A1 Adenosine Receptor Allosteric Enhancers

Ai ADENOSINE RECEPTOR ALLOSTERIC ENHANCERS

Government Rights

The present invention was made with the assistance of U.S. Government funding (National Heart, Blood, and Lung Institute Grant HL5611 (J.L.)). The U.S. Government may have certain rights in this invention.

Field of Invention

The present invention relates generally to chemical compounds and methods for their use and preparation. In particular, the invention relates to chemical compounds which may possess useful therapeutic activity for treating conditions where the promotion of angiogensis (blood vessel formation) is beneficial, use of these compounds in therapy and the manufacture of medicaments as well as compositions containing these compounds.

Background of the Invention

Adenosine is an important endogenous tissue-protective compound released during ischaemia, hypoxia or inflammation. Adenosine interacts with extracellular G protein- coupled receptors to regulate adenylate cyclase, and potassium and calcium ion channels. Four receptor subtypes (Ai, A2A, A2B and A3) have been defined based on pharmacological properties and molecular cloning. Considerable effort has been directed toward developing therapeutic agents targeting these receptors. Adenosine (marketed as Adenocard™) was approved for use in the treatment of supraventricular tachycardia in the early 1990's. A new synthetic Ai adenosine receptor (AiAR) agonist, Tecadenosin™, is in clinical development as an anti-arrhythmic agent, while the mixed A]/A2AR agonist, AMP-579, reached phase II clinical trials as a cardioprotective agent. Despite these advances, development of adenosine receptor agonists as therapeutic agents has been limited by side-effects associated with actions at adenosine receptors located in tissues away from the desired site(s) of action, and the propensity of agonists to cause receptor desensitization upon prolonged exposure. Such problems need to be addressed in order to take advantage of the enormous therapeutic potential of the adenosine receptor system. In this respect, allosteric modulators may prove clinically valuable, with improved therapeutic indices owing to their site and event-selective actions. Allosteric enhancers bind to an allosteric site, potentiating responses to agonist binding at the primary binding domain (or orthosteric site). Since adenosine production is highest in ischaemic or hypoxic tissue, enhancers that selectively amplify the actions of endogenous adenosine would be selective for ischaemic tissue. Since extracellular adenosine is very rapidly degraded to inactive metabolites, within the circulation and interstitial compartments, amplifying the effects of endogenous adenosine would localize its actions to those cells undergoing ischemic stress. Agents inducing such site and event specific effects clearly offer a therapeutic advantage.

Routine screening for adenosine antagonists by Parke-Davis identified a series of 2-amino- 3-benzoylthiophenes that enhanced agonist radioligand binding at A1ARs (see Bruns, et al., MoI. Pharmacol, 1990, 38, 939-949 & 950-958). In particular, these compounds were found to increase binding of [3H]N6-cyclohexyladenosine (CHA) to adenosine A1 receptors and cause a functional enhancement of the effects of adenosine A1 receptor activation in tissue. It appears that these "allosteric enhancers" enhance the A1 adenosine receptor function by stabilising the high affinity state of the receptor-G-protein complex. The above mentioned allosteric enhancers offer many therapeutic benefits, as adenosine receptor A1 agonists in general promote angiogensis (blood vessel formation) and selective Ai allosteric enhancers may selectively stimulate angiogensis in ischemic or hypoxic tissues that produce high levels of adenoside, as opposed to tissue where the adenosine concentration is low. The most effective enhancer in this series was PD81,723 (1) which proved highly selective for A]ARs, having no major effect on agonist binding at the other adenosine receptor subtypes or at the other G-protein coupled receptors that were investigated (M2 muscarinic, α2 adrenergic or γ-opiate receptors). The initial structure- activity study performed by Parke-Davis established that the amino and ketone groups were important in maintaining good activity. More detailed structure-activity relationships of 2-aniinothiophene, 2-amino-4,5,6,7-tetrahydrobenzo[δ]thiophene and 2-amino-6- benzyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridine cores have subsequently been reported (see, for instance, Figler, H., et al., MoI. Pharmacol, 2003, 64, 1557-64; van der Klein, P.A.M, et al., J Med. Chem. 1999, 42, 3629-3635; Kourounakis, A.P., et al., Drug Dev. Res. 2000, 49, 227-237; Baraldi, P.G., et al., Bioorg. Med. Chem. Lett. 2000, 10, 1953-1957; Tranberg, C.E., et al., J Med. Chem. 2002, 45, 382-389; Lϋtjens, H., et al., J Med. Chem. 2003, 46, 1870-1877; Baraldi, P.G., et al., Eur. J. Med. Chem. 2004, 39, 855-65; and Figler, H., et al., MoI. Pharmacol. 2003, 64, 1557-64.).

(1)

The present invention provides novel substituted thiophenes as useful Ai adenosine receptor allosteric enhancers.

Summary of the Invention

The present invention provides compounds of formula (I) and salts thereof;

wherein: n and m are independently an integer from 0 to 3; and each Ri and R2 independently represents carboxyl, cyano, dihalomethoxy, halogen, hydroxy, nitro, pentahaloethyl, phosphono, phosphorylamino, phosphinyl, thio, - A -

sulfinyl, sulfonyl, trihaloethenyl, trihalomethanethio, trihalomethoxy, trihalomethyl, optionally substituted acyl, optionally substituted acylamino, optionally substituted acylimino, optionally substituted acyliminoxy, optionally substituted acyloxy, optionally substituted arylalkyl, optionally substituted arylalkoxy, optionally substituted alkenyl, optionally substituted alkenyloxy, optionally substituted alkoxy, optionally substituted alkyl, optionally substituted alkynyl, optionally substituted alkynyloxy, optionally substituted amino, optionally substituted aminoacyl, optionally substituted aminoacyloxy, optionally substituted aminosulfonyl, optionally substituted aminothioacyl, optionally substituted aryl, optionally substituted arylamino, optionally substituted aryloxy, optionally substituted cycloalkenyl, optionally substituted cycloalkyl, optionally substituted heteroaryl, optionally substituted heterocyclyl, optionally substituted oxyacyl, optionally substituted oxyacylamino, optionally substituted oxyacyliniino, optionally substituted oxyacyloxy, optionally substituted oxysulfmylamino, optionally substituted oxysulfonylamino, optionally substituted oxythioacyl, optionally substituted oxythioacyloxy, optionally substituted sulfmyl, optionally substituted sulfmylamino, optionally substituted sulfonyl, optionally substituted sulphonylamino, optionally substituted thio, optionally substituted thioacyl, optionally substituted thioacylamino, or optionally substituted thioacyloxy.

The present invention further provides compounds of formula (II) and salts thereof;

wherein: n is an integer from 0 to 3;

Ri independently represents carboxyl, cyano, dihalomethoxy, halogen, hydroxy, nitro, pentahaloethyl, phosphono, phosphorylamino, phosphinyl, thio, sulfinyl, sulfonyl, trihaloethenyl, trihalomethanethio, trihalomethoxy, trihalomethyl, optionally substituted acyl, optionally substituted acylamino, optionally substituted acylimino, optionally substituted acyliminoxy, optionally substituted acyloxy, optionally substituted arylalkyl, optionally substituted arylalkoxy, optionally substituted alkenyl, optionally substituted alkenyloxy, optionally substituted alkoxy, optionally substituted alkyl, optionally substituted alkynyl, optionally substituted alkynyloxy, optionally substituted amino, optionally substituted aminoacyl, optionally substituted aminoacyloxy, optionally substituted aminosulfonyl, optionally substituted aminothioacyl, optionally substituted aryl, optionally substituted arylamino, optionally substituted aryloxy, optionally substituted cycloalkenyl, optionally substituted cycloalkyl, optionally substituted heteroaryl, optionally substituted heterocyclyl, optionally substituted oxyacyl, optionally substituted oxyacylamino, optionally substituted oxyacylimino, optionally substituted oxyacyloxy, optionally substituted oxysulfmylamino, optionally substituted oxysulfonylamino, optionally substituted oxythioacyl, optionally substituted oxythioacyloxy, optionally substituted sulfmyl, optionally substituted sulfinylamino, optionally substituted sulfonyl, optionally substituted sulphonylamino, optionally substituted thio, optionally substituted thioacyl, optionally substituted thioacylamino, or optionally substituted thioacyloxy;

R3 represents halogen; and R4 represents Ci-3 alkyl.

Brief Description of the Figures

Figure 1 - depicts a graph of Ai adenosine receptor-mediated ERKl /2 phosphorylation in response to the agonist, R-PIA (relative to that mediated by an internal control of 3% FBS stimulation), in the absence or presence of various concentrations of Example 1.

Figure 2 - depicts a graph of Ai adenosine receptor-mediated [35S]GTPyS binding in response to the agonist, R-PIA, in the absence or presence of various concentrations of Example 1.

Figure 3 - depicts a graph of Aj adenosine receptor-mediated ERKl /2 phosphorylation in response to the agonist, R-PIA (relative to that mediated by an internal control of 3% FBS stimulation), in the absence or presence of two concentrations of each of the indicated Example compounds.

Description of Preferred Embodiments

"Alkyl" refers to monovalent alkyl groups which may be straight chained or branched and preferably have from 1 to 10 carbon atoms or more preferably 1 to 6 carbon atoms and most preferably 1 to 3 carbon atoms. Examples of such alkyl groups include methyl, ethyl, π-propyl, wo-propyl, «-butyl, wo-butyl, «-hexyl, and the like.

"Aryl" refers to an unsaturated aromatic carbocyclic group having a single ring (eg. phenyl) or multiple condensed rings (eg. naphthyl or anthryl), preferably having from 6 to 14 carbon atoms. Examples of aryl groups include phenyl, naphthyl and the like.

"Aryloxy" refers to the group aryl-O- wherein the aryl group is as described above.

"Arylalkyl" refers to -alkylene-aryl groups preferably having from 1 to 10 carbon atoms in the alkylene moiety and from 6 to 10 carbon atoms in the aryl moiety. Such arylalkyl groups are exemplified by benzyl, phenethyl and the like.

"Arylalkoxy" refers to the group arylalkyl-O- wherein the arylalkyl group are as described above. Such arylalkoxy groups are exemplified by benzyloxy and the like.

"Alkoxy" refers to the group alkyl-O- where the alkyl group is as described above. Examples include, methoxy, ethoxy, n-propoxy, zsø-propoxy, n-bntoxy, tert-bntoxy, sec- butoxy, rø-pentoxy, n-hexoxy, 1 ,2-dimethylbutoxy, and the like. "Alkenyl" refers to a monovalent alkenyl group which may be straight chained or branched and preferably have from 2 to 10 carbon atoms and more preferably 2 to 6 carbon atoms and have at least 1 and preferably from 1-2, carbon to carbon, double bonds. Examples include ethenyl (-CH=CH2), rc-propenyl (-CH2CH=CH2), ijo-propenyl (-C(CH3)OH2), but-2-enyl (-CH2CH=CHCH3), and the like.

"Alkenyloxy" refers to the group alkenyl-O- wherein the alkenyl group is as described above.

"Alkynyl" refers to alkynyl groups preferably having from 2 to 10 carbon atoms and more preferably 2 to 6 carbon atoms and having at least 1, and preferably from 1-2, carbon to carbon, triple bonds. Examples of alkynyl groups include ethynyl (-C≡ CH), propargyl (-CH2C= CH), pent-2-ynyl (-CH2C=CCH2-CH3), and the like.

"Alkynyloxy" refers to the group alkynyl-O- wherein the alkynyl groups is as described above.

"Acyl" refers to groups H-C(O)-, alkyl-C(O)-, cycloalkyl-C(O)-, aryl-C(O)-, heteroaryl- C(O)- and heterocyclyl-C(O)-, where alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl are as described herein.

"Oxyacyl" refers to groups alkyl-OC(O)-, cycloalkyl-OC(O)-, aryl-OC(O)-, heteroaryl- OC(O)-, and heterocyclyl-OC(O)-, where alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl are as described herein.

"Amino" refers to the group -NR*R* where each R* is independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl and where each of alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl is as described herein.

"Aminoacyl" refers to the group -C(0)NR*R* where each R* is independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl and where each of alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl is as described herein.

"Acylamino" refers to the group -NR* C(O)R* where each R* is independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl and where each of alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl are as described herein.

"Acyloxy" refers to the groups -OC(O)-alkyl, -OC(O)-aryl, -OC(O)-heteroaryl, and -OC(O)-heterocyclyl where alkyl, aryl, heteroaryl and heterocyclyl are as described herein.

"Aminoacyloxy" refers to the groups -OC(O)NR*-alkyl, -OC(O)NR* -aryl, -OC(O)NR* -heteroaryl, and -OC(O)NR* -heterocyclyl where R* is independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl and where each of alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl is as described herein.

"Oxyacylamino" refers to the groups -NR*C(0)0-alkyl, -NR*C(O)O-aryl, -NR*C(O)O-heteroaryl, and NR*C(O)O-heterocyclyl where R* is independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl and where each of alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl is as described herein.

"Oxyacyloxy" refers to the groups -OC(O)O-alkyl, -OC(O)O-aryl, -OC(O)O- heteroaryl, and -OC(O)O-heterocyclyl where alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl are as described herein.

"Acylimino" refers to the groups -C(NR*)-R* where each R* is independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl and where each of alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl are as described herein.

"Acyliminoxy" refers to the groups -0-C(NR*)-R* where each R* is independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl and where each of alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl are as described herein. "Oxyacylimino" refers to the groups -C(NR*)-OR* where each R* is independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl and where each of alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl are as described herein.

"Cycloalkyl" refers to cyclic alkyl groups having a single cyclic ring or multiple condensed rings, preferably incorporating 3 to 8 carbon atoms. Such cycloalkyl groups include, by way of example, single ring structures such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, and the like, or multiple ring structures such as adamantanyl, and the like.

"Cycloalkenyl" refers to cyclic alkenyl groups having a single cyclic ring and at least one point of internal unsaturation, preferably incorporating 4 to 8 carbon atoms. Examples of suitable cycloalkenyl groups include, for instance, cyclobut-2-enyl, cyclopent-3-enyl, cyclohex-4-enyl, cyclooct-3-enyl and the like.

"Halo" or "halogen" refers to fluoro, chloro, bromo and iodo.

"Heteroaryl" refers to a monovalent aromatic heterocyclic group which fulfils the Huckel criteria for aromaticity (ie. contains 4n + 2 π electrons) and preferably has from

2 to 10 carbon atoms and 1 to 4 heteroatoms selected from oxygen, nitrogen, selenium, and sulfur within the ring (and includes oxides of sulfur, selenium and nitrogen). Such heteroaryl groups can have a single ring (eg. pyridyl, pyrrolyl or N-oxides thereof or furyl) or multiple condensed rings (eg. indolizinyl, benzoimidazolyl, coumarinyl, quinolinyl, isoquinolinyl or benzothienyl).

"Heterocyclyl" refers to a monovalent saturated or unsaturated group having a single ring or multiple condensed rings, preferably from 1 to 8 carbon atoms and from 1 to 4 hetero atoms selected from nitrogen, sulfur, oxygen, selenium or phosphorous within the ring. Examples of heterocyclyl and heteroaryl groups include, but are not limited to, oxazole, pyrrole, imidazole, pyrazole, pyridine, pyrazine, pyrimidine, pyridazine, indolizine, isoindole, indole, indazole, purine, quinolizine, isoquinoline, quinoline, phthalazine, naphthylpyridine, quinoxaline, quinazoline, cinnoline, pteridine, carbazole, carboline, phenanthridine, acridine, phenanthroline, isothiazole, phenazine, isoxazole, isothiazole, phenoxazine, phenothiazine, imidazolidine, imidazoline, piperidine, piperazine, indoline, phthalimide, 1,2,3,4-tetrahydroisoquinoline, 4,5,6,7-tetrahydrobenzo[b]thiophene, thiazole, thiadiazoles, oxadiazole, oxatriazole, tetrazole, thiazolidine, thiophene, benzo[b]thiophene, morpholino, piperidinyl, pyrrolidine, tetrahydrofuranyl, triazole, and the like.

"Thio" refers to groups H-S-, alkyl-S-, cycloalkyl-S-, aryl-S-, heteroaryl-S-, and heterocyclyl-S-, where alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl are as described herein.

"Thioacyl" refers to groups H-C(S)-, alkyl-C(S)-, cycloalkyl-C(S)-, aryl-C(S)-, heteroaryl-C(S)-, and heterocyclyl-C(S)-, where alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl are as described herein.

"Oxythioacyl" refers to groups HO-C(S)-, alkylO-C(S)-, cycloalkylO-C(S)-, arylO- C(S)-, heteroarylO-C(S)-, and heterocyclylO-C(S)-, where alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl are as described herein.

"Oxythioacyloxy" refers to groups HO-C(S)-O-, alkylO-C(S)-O-, cycloalkylO-C(S)-O-, arylO-C(S)-O-, heteroarylO-C(S)-O-, and heterocyclylO-C(S)-O-, where alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl are as described herein.

"Phosphorylamino" refers to the groups -NR* -P(O)(R* *)(OR***) where R* represents H, alkyl, cycloalkyl, alkenyl, or aryl, R** represents OR*** or is hydroxy or amino and R*** is alkyl, cycloalkyl, aryl or arylalkyl, where alkyl, amino, alkenyl, aryl, cycloalkyl, and arylalkyl are as described herein. "Thioacyloxy" refers to groups H-C(S)-O-, alkyl-C(S)-O-, cycloalkyl-C(S)-O-, aryl- C(S)-O-, heteroaryl-C(S)-O-, and heterocyclyl-C(S)-O-, where alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl are as described herein.

"Sulfinyl" refers to groups H-S(O)-, alkyl-S(O)-, cycloalkyl-S(O)-, aryl-S(O)-, heteroaryl-S(O)-, and heterocyclyl-S(O)-, where alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl are as described herein.

"Sulfonyl" refers to groups H-S(O)2-, alkyl-S(O)2-, cycloalkyl-S(O)2-, aryl-S(O)2-, heteroaryl-S(O)2-, and heterocyclyl-S(O)2-, where alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl are as described herein.

"Sulfmylamino" refers to groups H-S(O)-NR*-, alkyl-S(O)-NR*-, cycloalkyl-S(O)- NR*-, aryl-S(O)-NR*-, heteroaryl-S(O)-NR*-, and heterocyclyl-S(O)-NR*-, where R* is independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl and where each of alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl is as described herein.

"Sulfonylamino" refers to groups H-S(O)2-NR*-, alkyl-S(O)2-NR*-, cycloalkyl-S(O)2- NR*-, aryl-S(O)2-NR*-, heteroaryl-S(O)2-NR*-, and heterocyclyl-S(O)2-NR*-, where R* is independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl and where each of alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl is as described herein.

"Oxy sulfmylamino" refers to groups HO-S(O)-NR*-, alkylO-S(O)-NR*-, cycloalkylO- S(O)-NR*-, arylO-S(O)-NR*-, heteroarylO-S(O)-NR*-, and heterocyclylO-S(O)-NR*-, where R* is independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl and where each of alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl is as described herein. "Oxysulfonylamino" refers to groups HO-S(O)2-NR*-, alkylO-S(O)2-NR% cycloalkylO-S(O)2-NR*-, arylO-S(O)2-NR*-, heteroarylO-S(O)2-NR*-, and heterocyclylO-S(O)2-NR*-, where R* is independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl and where each of alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl is as described herein.

"Aminothioacyl" refers to groups R*R*N-C(S)-, where each R* is independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclic and where each of alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl is as described herein.

"Thioacylamino" refers to groups H-C(S)-NR*-, alkyl-C(S)-NR*-, cycloalkyl-C(S)- NR*-, aryl-C(S)-NR*-, heteroaryl-C(S)-NR% and heterocyclyl-C(S)-NR*-, where R* is independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl and where each of alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl is as described herein.

"Aminosulfinyl" refers to groups R*R*N-S(0)-, where each R* is independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclic and where each of alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl is as described herein.

"Aminosulfonyl" refers to groups R*R*N-S(O)2-, where each R* is independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, and heterocyclic and where each of alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl is as described herein.

In this specification "optionally substituted" is taken to mean that a group may or may not be further substituted or fused (so as to form a condensed polycyclic group) with one or more groups selected from hydroxyl, acyl, alkyl (which may be further substituted by amino, aminoacyl, oxyacyl, hydroxy, aryl and nitro), alkoxy, alkenyl, alkenyloxy, alkynyl, alkynyloxy, amino, aminoacyl, thio, arylalkyl, arylalkoxy (which may be further substituted by halogen, hydroxy, alkyl, nitro, alkoxy, acyl and amino), aryl (which may be further substituted by halogen, hydroxy, alkyl, nitro, alkoxy, acyl and amino), aryloxy (which may be further substituted by halogen, hydroxy, alkyl, nitro, alkoxy, acyl and amino), carboxyl, acylamino, cyano, halogen, nitro, phosphono, sulfo, phosphoryl amino, phosphinyl, heteroaryl, heteroaryloxy, heterocyclyl, heterocyclyloxy, oxyacyl, oxime, oxime ether, hydrazone, oxyacylamino, oxysulfonylamino, aminoacyloxy, trihalomethyl, trialkylsilyl, pentafluoroethyl, trifluoromethoxy, difluoromethoxy, trifluoromethanethio, trifluoroethenyl, mono- and di-alkylamino, mono-and di-(substituted alkyl)amino, mono- and di-arylamino, mono- and di-heteroarylamino, mono- and di-heterocyclyl amino, and unsymmetric di- substituted amines having different substituents selected from alkyl, aryl, heteroaryl and heterocyclyl, and the like, and may also include a bond to a solid support material, (for example, substituted onto a polymer resin).

In some embodiments R1 includes the following groups: lower alkoxy; nitro; trihalomethyl, including trifluoromethane; and halogen, including chloro, bromo and fluoro.

In an embodiment of the compounds of formulae (I) and (II) n is 1 or 2 and in another embodiment n is 1.

In some embodiments R2 includes the following groups: halogen, preferably chloro.

In some embodiments of compounds of formula (I) m is 0 or 1 and in another embodiment m is 0. In a further embodiment n is 1 or 2 and m is 0 or 1, in other embodiments of compounds of formula (I) n is 1 and m is 0, n is 2 and m is 0, n is 1 and m is 1, or n is 2 and m is 1.

In a further more preferred embodiment of the compounds of formulae (I) and (II) n is 1 or 2 and each Ri when present is an electron withdrawing group. Most preferred electron withdrawing groups for Rj include halogen, nitro, trihaloethenyl, trihalomethanethio, trihalomethoxy, and trihalomethyl. More preferably R1 is nitro, halo, trihalomethyl, and even more preferably R1 is nitro, trifluoromethyl, bromo, chloro, or fluoro.

Preferably the Ri group is positioned ortho or meta (more preferably meta) on the phenyl ring relative to the point of attachment to the thiophene (i.e. for example 3-Cl, 3-F, 3-CF3 or 3,5-di-CF3).

Accordingly, in a preferred embodiment n is 1 or 2 and R1 is nitro, halo, trifluoromethane, wherein R1 is positioned meta on the phenyl ring relative to the point of attachment to the thiophene.

With specific reference to formula (I) most preferably n is 1 , R1 is halo or trifluoromethane (wherein R] is positioned meta on the phenyl ring relative to the point of attachment to the thiophene (i.e., for example, 3-F or 3-CF3)) and m is 0 or 1.

In an embodiment formula (I) is a compound of formula (F) or salt thereof:

Wherein

R1 a and R^ are each independently selected from hydrogen, halo, and trifluoromethyl, provided that not both Rla and Rib are hydrogen; and R2a is selected from hydrogen or halo.

In one embodiment, for compounds of formula (I1), Ri3 is Cl, F5 or CF3 and R]b is hydrogen and R2a is hydrogen or chloro. In another embodiment, for compounds of formula (I1), R1 a and R^ are both CF3.

In yet another embodiment of compounds of formula (I1), Rla is CF3, Cl, or F, Ru, is hydrogen and R2a is hydrogen.

In yet another embodiment of compounds of formula (I1), Ri3 is CF3, Cl, or F, Rj b is hydrogen and R2a is chloro.

For compounds of formula (II) most preferably R3 is halogen and R4 is ethyl or methyl. Even more preferably the halogen is positioned para on the phenyl ring relative to the point of attachment to the thiophene. More preferably R3 is chloro (wherein R3 is positioned para on the phenyl ring relative to the point of attachment to the thiophene, (i.e. 4-chloro)) and R4 is ethyl.

The compounds of formulae (I) and (II) may be prepared by the reaction sequence depicted in Scheme 1 below (wherein R5 is -OR4 or -Ph-(-R2)m; R6 is -Ph-(-R3); Pr is a protecting group and X is Br or I).

(iii)

(6) (5) - 17 -

few steps. Accordingly, it would be appreciated that the reaction sequence depicted in Scheme 1 provides not only easy access to compounds of formula I and II but also provides the artisan with access to a range of variously 5-substituted 2-amino-thiophenes for further investigating the structure activity relationship of the 5 -position.

Accordingly, the invention also provides a method of preparing compounds of formula (III) and salts thereof:

said method comprising the steps of:

a) coupling a compound of formula (Ilia) with a substituted acetonitrile of formula (HJb)

(HIa) (nib)

to form a compound of formula (UIc)

b) cyclising the compound of formula (IHc) in the presence of elemental sulphur to form a thiophene of formula (HId) - 16 -

Scheme 1. (i) R5C(O)CH2CN, TiCl4, pyridine, CH2Cl2; (ii) sulphur, Et2NH, EtOH or THF; (iii) Boc2O, DMAP, dioxane; (iv) NBS, AcOH/CH2Cl2; (v) Method A: R6B(OH)2, 3 mol% Pd[P(Ph)3]4, K3PO4, DMFVH2O or Method B: R6B(OH)2, 3 mol% Pd(PPh3)2Cl2, K3PO4, toluene/H2O, boronic acid, 150 0C MW; (vi) TFA, CH2Cl2 or 6M HCl, EtOH.

Scheme 1 represents a linear synthetic sequence which may prepare both compounds of formula (I) (steps (i) and (ii)) and compounds of formula (II) (including additional steps (iii)-(vi)).

As depicted in Scheme 1 the thiophene core may be formed via a two step Gewald synthesis in which a substituted acetophenone (2) may be initially reacted with either a substituted benzoylacetonitrile or a Cj-3 alkyl cyanoacetate, in the presence of titanium(IV)chloride to afford the corresponding Knoevenagel product (3). This olefin may be subsequently cyclised with sulphur under basic conditions to yield the desired 2- aminothiophene (for instance, compounds of formula I where R5 is -Ph-(-R2)m). The free amino product (4) may be optionally protected before proceeding, for instance using any suitable amino protecting group such as Boc protection using BoC2O and catalytic DMAP in dioxane or phthaloyl protection. Other suitable protecting groups are known to those skilled in the art, for example, as described in Protective Groups in Organis Synthesis (T.W Greene and P.G.M Wutz, Wiley Interscience, New York, 3rd edition). The protected 2-aminothiophene (5) may then be converted to the corresponding 5-halo-analog (6) using a suitable halogenating agent such as N-bromosuccinimide. The R6 group may be introduced by a Pd mediated cross coupling reaction such as using Suzuki-Miyaura cross coupling conditions in DMF/H20 mixtures with tribasic potassium phosphate and catalytic Pd(PPh3)4 in an inert atmosphere (N2) with heating (70-80 °C) in a 24 h period or alternatively under microwave irradiation. The resultant protected cross coupled product may then be deprotected, if required, to afford (7) (compounds of formula II, when R6 is - Ph-(-R3) and R5 is -OR4). The crude isolated product (7) may be purified by recrystallisation or column chromatography.

In the above described sequence the 5-substituent on the thiophene is installed in the last and optionally protecting the 2-amino group on the compound of formula (HId);

c) halogenating the 5-position of the compound of formula (HId) to form a compound of formula (HIe)

d) coupling the compound of formula (HIe) with a compound of formula (HIf) in the presence of a palladium coupling agent R7-Z CIHf) and optionally deprotecting the 2-amino group to form a compound of formula (III);

wherein: n is an integer from 0 to 3; each Rj independently represents carboxyl, cyano, dihalomethoxy, halogen, hydroxy, nitro, pentahaloethyl, phosphono, phosphorylamino, phosphinyl, thio, sulfinyl, sulfonyl, trihaloethenyl, trihalomethanethio, trihalomethoxy, trihalomethyl, optionally substituted acyl, optionally substituted acylamino, optionally substituted acyliniino, optionally substituted acyliminoxy, optionally substituted acyloxy, optionally substituted arylalkyl, optionally substituted arylalkoxy, optionally substituted alkenyl, optionally substituted alkenyloxy, optionally substituted alkoxy, optionally substituted alkyl, optionally substituted alkynyl, optionally substituted alkynyloxy, optionally substituted amino, optionally substituted aminoacyl, optionally substituted aminoacyloxy, optionally substituted aminosulfonyl, optionally substituted aminothioacyl, optionally substituted aryl, optionally substituted arylamino, optionally substituted aryloxy, optionally substituted cycloalkenyl, optionally substituted cycloalkyl, optionally substituted heteroaryl, optionally substituted heterocyclyl, optionally substituted oxyacyl, optionally substituted oxyacylamino, optionally substituted oxyacylimino, optionally substituted oxyacyloxy, optionally substituted oxysulfmylamino, optionally substituted oxysulfonylamino, optionally substituted oxythioacyl, optionally substituted oxythioacyloxy, optionally substituted sulfinyl, optionally substituted sulfinylamino, optionally substituted sulfonyl, optionally substituted sulphonylamino, optionally substituted thio, optionally substituted thioacyl, optionally substituted thioacylamino, or optionally substituted thioacyloxy; R5 is (1) -Ph-(R2)Oi where m is an integer from 0 to 3 and each R2 independently represents carboxyl, cyano, dihalomethoxy, halogen, hydroxy, nitro, pentahaloethyl, phosphono, phosphorylamino, phosphinyl, thio, sulfinyl, sulfonyl, trihaloethenyl, trihalomethanethio, trihalomethoxy, trihalomethyl, optionally substituted acyl, optionally substituted acylamino, optionally substituted acylimino, optionally substituted acyliminoxy, optionally substituted acyloxy, optionally substituted arylalkyl, optionally substituted arylalkoxy, optionally substituted alkenyl, optionally substituted alkenyloxy, optionally substituted alkoxy, optionally substituted alkyl, optionally substituted alkynyl, optionally substituted alkynyloxy, optionally substituted amino, optionally substituted aminoacyl, optionally substituted aminoacyloxy, optionally substituted aminosulfonyl, optionally substituted aminothioacyl, optionally substituted aryl, optionally substituted arylamino, optionally substituted aryloxy, optionally substituted cycloalkenyl, optionally substituted cycloalkyl, optionally substituted heteroaryl, optionally substituted heterocyclyl, optionally substituted oxyacyl, optionally substituted oxyacylamino, optionally substituted oxyacylimino, optionally substituted oxyacyloxy, optionally substituted oxysulfmylamino, optionally substituted oxysulfonylamino, optionally substituted oxythioacyl, optionally substituted oxythioacyloxy, optionally substituted sulfinyl, optionally substituted sulfinylamino, optionally substituted sulfonyl, optionally substituted sulphonylamino, optionally substituted thio, optionally substituted thioacyl, optionally substituted thioacylamino, or optionally substituted thioacyloxy; or (2) -OR4' where R4' represents optionally substituted C)-3 alkyl, optionally substituted aryl;

R7 is optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkenyl, optionally substituted alkyl, optionally substituted alkynyl; Hal is chloro, bromo or iodo; and

Z is halogen, triflate, sulfonate, BrZn, Sn(alkyl)3, Sn(aryl)3 or B(OR8)2 where Rs is H or alkyl.

In relation to step d) above, the coupling of formulae (UIe) and (IHf) may be carried out under a range of conditions known to those skilled in art of Pd based coupling reactions.

Apart from the Suzuki-Miyaura conditions discussed earlier, compounds where R7 is an optionally substituted alkenyl or optionally substituted alkynyl may be prepared using standard Stille (with reactive stannanes), Hiyama or Sonogashira (with catalytic Cu) reaction conditions. Negishi conditions with organozinc reagents may afford R7 substituents which are optionally substituted aryl.

Examples of suitable Pd coupling agents which may be employed in the reaction conditions discussed above include: Pd(PPli3)2Cl2, Pd(PPh3)4, Pd(dibenzylideneacetone)3, PdCl2(CH3CN)2, Pd(OAc)2, and the like.

Past work by Brans (see, for instance, MoI. Pharmacol,, 1990, 38, 939) has shown that certain 2-amino-3-aroylthiophenes enhance adenosine binding and the functional activation of the Ai receptor in cardiovascular and heart tissue. The compounds of the present invention have been found to have improved activity at the Ai receptor, in particular, in comparison to the compound of formula (1) which was investigated as part of the work reported by Brans and co-workers.

Without wishing to be bound by theory it is believed that the improved activity of the present invention may be as a result of the present compounds possessing enhanced allosteric effects while also minimising antagonistic activity at adenosine Aj receptors. It has now been found that the activity of thiophene based allosteric enhancers may be improved by selecting particular substitution patterns. For instance, improved activity has been found in compounds of formula (I) where the 5-position of 2-aminothiophenes is unsubstituted, the 3-position bears an optionally substituted benzoyl moiety, and the 4- position bears an optionally substituted aryl moiety, Improved activity has also been found in compounds of formula (II) where the 5-position of 2-aminothiophenes bears a 4- halophenyl moiety, the 3-position bears a Ci-3 alkyl carboxylate, and the 4-position bears an optionally substituted aryl moiety.

Accordingly, as the compounds of the invention serve to enhance adenosine binding and functional activation at the Aj receptor they may be useful in general cardioprotective therapies which respond well to the promotion of angiogenesis. Such cardioprotective therapies may include protection against conditions such as hypoxia, ischemia (including strokes, heart disease, and peripheral vascular disease), induced injury as well as adenosine-sensitive cardiac arrthythmias and seizures.

Similar thiophene based compounds have also been found (see Pan et al, Anesthesiology, 2001, 95, 416) to be capable of mitigating allodynia and therefore may also find use in managing chronic, neuropathic and acute pain states.

Thus, the invention also provides for the use of a compound of formulae (I) or (II) in the manufacture of a medicament for treating or managing pain or as a cardioprotective agent.

There is also provided a method of treating or managing pain or providing cardioprotection comprising the administration of an effective amount of a compound of formula (I) or (II) to a subject in need thereof.

The compounds of the invention may be particularly useful in combination therapy, eg. combining the treatment with other chemotherapeutic treatments. For instance, the compounds of the present invention may be used in combination with an orthosteric agonist, thus boosting the latter's efficacy. However, it will be understood that the compounds of the invention can be used in the treatment of any disease state for which the enhancement of adenosine binding and functional activation of Ai adenosine receptors may be beneficial.

Compounds of the present invention can be formulated as a composition, particularly a pharmaceutical composition, together with a pharmaceutically acceptable additive.

The compounds of the invention are administered to the subject in a treatment effective amount. As used herein, a treatment effective amount is intended to include at least partially attaining the desired effect, or delaying the onset of, or inhibiting the progression of, or halting or reversing altogether the onset or progression of the particular disease of condition being treated.

As used herein, the term "effective amount" relates to an amount of compound which, when administered according to a desired dosing regimen, provides the desired therapeutic activity. Dosing may occur at intervals of minutes, hours, days, weeks, months or years or continuously over any one of these periods. Suitable dosages lie within the range of about 0.1 ng per kg of body weight to 1 g per kg of body weight per dosage. The dosage may be in the range of 1 μg to 1 g per kg of body weight per dosage, such as is in the range of 1 mg to 1 g per kg of body weight per dosage. In one embodiment, the dosage may be in the range of 1 mg to 500 mg per kg of body weight per dosage. In another embodiment, the dosage may be in the range of 1 mg to 250 mg per kg of body weight per dosage. In yet another preferred embodiment, the dosage may be in the range of 1 mg to 100 mg per kg of body weight per dosage, such as up to 50 mg per body weight per dosage.

Suitable dosage amounts and dosing regimens can be determined by the attending physician and may depend on the particular condition being treated, the severity of the condition as well as the general age, health and weight of the subject. The active ingredient may be administered in a single dose or a series of doses. While it is possible for the active ingredient to be administered alone, it is preferable to present it as a composition, preferably as a pharmaceutical composition. The formulation of such compositions is well known to those skilled in the art. The composition may contain any suitable carriers, diluents or excipients. These include all conventional solvents, dispersion media, fillers, solid carriers, coatings, antifungal and antibacterial agents, dermal penetration agents, surfactants, isotonic and absorption agents and the like. It will be understood that the compositions of the invention may also include other supplementary physiologically active agents.

The carrier must be pharmaceutically "acceptable" in the sense of being compatible with the other ingredients of the composition and not injurious to the subject. Compositions include those suitable for oral, rectal, nasal, topical (including buccal and sublingual), vaginal or parental (including subcutaneous, intramuscular, intravenous and intradermal) administration. The compositions may conveniently be presented in unit dosage form and may be prepared by any methods well known in the art of pharmacy. Such methods include the step of bringing into association the active ingredient with the carrier which constitutes one or more accessory ingredients. In general, the compositions are prepared by uniformly and intimately bringing into association the active ingredient with liquid carriers or finely divided solid carriers or both, and then if necessary shaping the product.

Compositions of the present invention suitable for oral administration may be presented as discrete units such as capsules, sachets or tablets each containing a predetermined amount of the active ingredient; as a powder or granules; as a solution or a suspension in an aqueous or non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil liquid emulsion. The active ingredient may also be presented as a bolus, electuary or paste.

A tablet may be made by compression or moulding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine the active ingredient in a free-flowing form such as a powder or granules, optionally mixed i with a binder (e.g inert diluent, preservative disintegrant (e.g. sodium starch glycolate, cross-linked polyvinyl pyrrolidone, cross-linked sodium carboxymethyl cellulose) surface- active or dispersing agent. Moulded tablets may be made by moulding in a suitable machine a mixture of the powdered compound moistened with an inert liquid diluent. The tablets may optionally be coated or scored and may be formulated so as to provide slow or controlled release of the active ingredient therein using, for example, hydroxypropylmethyl cellulose in varying proportions to provide the desired release profile. Tablets may optionally be provided with an enteric coating, to provide release in parts of the gut other than the stomach.

Compositions suitable for topical administration in the mouth include lozenges comprising the active ingredient in a flavoured base, usually sucrose and acacia or tragacanth gum; pastilles comprising the active ingredient in an inert basis such as gelatine and glycerin, or sucrose and acacia gum; and mouthwashes comprising the active ingredient in a suitable liquid carrier.

Compositions suitable for topical administration to the skin may comprise the compounds dissolved or suspended in any suitable carrier or base and may be in the form of lotions, gel, creams, pastes, ointments and the like. Suitable carriers include mineral oil, propylene glycol, polyoxyethylene, polyoxypropylene, emulsifying wax, sorbitan monostearate, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water. Transdermal patches may also be used to administer the compounds of the invention.

Compositions for rectal administration may be presented as a suppository with a suitable base comprising, for example, cocoa butter, glycerin, gelatine or polyethylene glycol.

Compositions suitable for vaginal administration may be presented as pessaries, tampons, creams, gels, pastes, foams or spray formulations containing in addition to the active ingredient such carriers as are known in the art to be appropriate. Compositions suitable for parenteral administration include aqueous and non-aqueous isotonic sterile injection solutions which may contain anti-oxidants, buffers, bactericides and solutes which render the composition isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents. The compositions may be presented in unit-dose or multi-dose sealed containers, for example, ampoules and vials, and may be stored in a freeze-dried (lyophilised) condition requiring only the addition of the sterile liquid carrier, for example water for injections, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets of the kind previously described.

Preferred unit dosage compositions are those containing a daily dose or unit, daily sub- dose, as herein above described, or an appropriate fraction thereof, of the active ingredient.

It should be understood that in addition to the active ingredients particularly mentioned above, the compositions of this invention may include other agents conventional in the art having regard to the type of composition in question, for example, those suitable for oral administration may include such further agents as binders, sweeteners, thickeners, flavouring agents disintegrating agents, coating agents, preservatives, lubricants and/or time delay agents. Suitable sweeteners include sucrose, lactose, glucose, aspartame or saccharine. Suitable disintegrating agents include cornstarch, methylcellulose, polyvinylpyrrolidone, xanthan gum, bentonite, alginic acid or agar. Suitable flavouring agents include peppermint oil, oil of wintergreen, cherry, orange or raspberry flavouring. Suitable coating agents include polymers or copolymers of acrylic acid and/or methacrylic acid and/or their esters, waxes, fatty alcohols, zein, shellac or gluten. Suitable preservatives include sodium benzoate, vitamin E, alpha-tocopherol, ascorbic acid, methyl paraben, propyl paraben or sodium bisulphite. Suitable lubricants include magnesium stearate, stearic acid, sodium oleate, sodium chloride or talc. Suitable time delay agents include glyceryl monostearate or glyceryl distearate. Preferably, the compounds of the present invention may be administered to a subject as a pharmaceutically acceptable salt. It will be appreciated however that non- pharmaceutically acceptable salts also fall within the scope of the present invention since these may be useful as intermediates in the preparation of pharmaceutically acceptable salts. Suitable pharmaceutically acceptable salts include, but are not limited to salts of pharmaceutically acceptable inorganic acids such as hydrochloric, sulphuric, phosphoric, nitric, carbonic, boric, sulfamic, and hydrobromic acids, or salts of pharmaceutically acceptable organic acids such as acetic, propionic, butyric, tartaric, maleic, hydroxymaleic, fumaric, maleic, citric, lactic, mucic, gluconic, benzoic, succinic, oxalic, phenylacetic, methanesulphonic, toluenesulphonic, benezenesulphonic, salicyclic sulphanilic, aspartic, glutamic, edetic, stearic, palmitic, oleic, lauric, pantothenic, tannic, ascorbic and valeric acids.

Base salts include, but are not limited to, those formed with pharmaceutically acceptable cations, such as sodium, potassium, lithium, calcium, magnesium, ammonium and alkylammonium. In particular, the present invention includes within its scope cationic salts eg sodium or potassium salts, or alkyl esters (eg methyl, ethyl) of the phosphate group.

Basic nitrogen-containing groups may be quarternised with such agents as lower alkyl halide, such as methyl, ethyl, propyl, and butyl chlorides, bromides and iodides; dialkyl sulfates like dimethyl and diethyl sulfate; and others.

It will be appreciated that any compound that is a prodrug of a compound of formula (I) is also within the scope and spirit of the invention. The term "pro-drug" is used in its broadest sense and encompasses those derivatives that are converted in vivo to the compounds of the invention. Such derivatives would readily occur to those skilled in the art, and include, for example, compounds where a free hydroxy group (for instance at the

Ri or R2 position) is converted into an ester, such as an acetate or phosphate ester, or where a free amino group is (for instance at the C-2 position of the thiophene or a Ri or R2 group) converted into an amide (eg. α-aminoacid amide). Procedures for esterifying, eg. acylating, the compounds of the invention are well known in the art and may include treatment of the compound with an appropriate carboxylic acid, anhydride or chloride in the presence of a suitable catalyst or base.

The compounds of the invention may be in crystalline form either as the free compounds or as solvates (e.g. hydrates) and it is intended that both forms are within the scope of the present invention. Methods of solvation are generally known within the art.

It will also be recognised that compounds of the invention may possess asymmetric centres and are therefore capable of existing in more than one stereoisomeric form. The invention thus also relates to compounds in substantially pure isomeric form at one or more asymmetric centres eg., greater than about 90% ee, such as about 95% or 97% ee or greater than 99% ee, as well as mixtures, including racemic mixtures, thereof. Such isomers may be prepared by asymmetric synthesis, for example using chiral intermediates, or mixtures may be resolved by conventional methods, eg., chromatography, or use of a resolving agent.

Furthermore, depending on the substitution pattern the compounds of the present invention may be capable of undergoing tautomerism. Accordingly, all possible tautomers of a compound of the present invention fall within the scope and spirit of the invention.

The synthetic methods and processes described herein to prepare the compounds of the present invention are amenable to solid phase synthetic techniques and/or combinatorial chemistry to produce individual compounds or libraries of compounds.

Traditionally, drug candidates have been synthesised individually, this being a time consuming and laborious process if the synthetic sequence contains even just a few steps and large numbers of compounds are to be evaluated for their biological activity. Combinatorial synthesis is an emerging technique for effecting the generation of large libraries of molecules and has been successfully exploited in the synthesis and evaluation of small organic libraries. These libraries and their starting substrates may exist as molecules in free solution or preferably, linked to a solid support, for example, beads, pins, microtitre plates (wells) or microchips which can be polymeric, glass, silica or other suitable substrate. Chemical diversity can be achieved by either parallel or split (split and mix) syntheses wherein each step has the potential to afford a multitude of compounds. Solution phase libraries may be prepared via parallel syntheses wherein different compounds are synthesised in separate reaction vessels in parallel, often in an automated fashion. Alternatively, attachment of the individual components employed in a synthetic sequence to an appropriate solid phase support allows for the further creation of chemical diversity by utilising not only parallel synthesis but also split synthesis wherein the solid support containing the compounds prepared in the prior step can be split into a number of batches, treated with the appropriate reagent and recombined.

The substrates can be attached to a solid support surface by any linkers known in the art. The linkers may be any component capable of being cleaved to release the substrate or final compound from the support.

Preferably, the solid support is a polymer support. Examples of polymeric supports currently used in solid phase synthesis include: alkenyl resins: eg. REM resins; BHA resins: eg. benzhydrylamine (polymer-bound hydrochloride, 2% crosslinked), benzhydryl chloride (polymer bound); Br- functionalised resins: eg. brominated PPOA resin, brominated Wang resin; Chloromethyl resins: eg. 4-methoxybenzhydryl chloride (polymer bound); CHO-functionalised resins: eg. indole resin, formylpolystyrene; Cl-functionalised resins: eg. Merrifield's resin, chloroacetyl (polymer bound); CChH-functionalised resins: eg. carboxypolystyrene; I-functionalised resins: eg. 4-iodophenol (polymer bound); Janda Jels™; MBHA resins: eg. 4-methylbenzhydrylamine hydrochloride (polymer bound), 4- hydroxymethylbenzoic acid-4-methyl benzhydrylamine (polymer bound); Amine- functionalised resins: eg. (aminomethyl)polystyrene, PAL resin, Sieber amide resin; Nitrophenyl carbonate resins: eg. 4-nitrophenyl carbonate (polymer bound); OH- functionalised resins: eg. 4-benzyloxybenzyl alcohol (polymer bound); Hydroxy methyl resins: eg. benzyl alcohol (polymer bound); HMBA resin; Oxime resins; Rink acid resin; Triazine-based resin; Trityl amine resins; Trityl resins: eg. trityl-chloride (polymer bound), 2-chlorotrityl alcohol, 1,3-diaminepropane trityl.

Thus, individual compounds or libraries of compounds can be synthesised by initially attaching the first compound substrate to a solid support surface which can be performed by providing a plurality of solid support surfaces, suitably derivatising each of the surfaces with groups capable of reacting with either the compound substrate or a linker moiety attached thereto. The various support surfaces with the attached first compound substrate can then be subjected to various reaction conditions and second compound substrates to provide a library of attached compounds, which may, if necessary, be reacted further with third and subsequent compound substrates or varying reactions conditions. Attachment and detachment of substrates and products can be performed under conditions similar to those as described in Johnson, M.G., et al, Tetrahedron, 1999, 55, 11641; Han Y., et al. Tetrahedron 1999, 55, 11669; and Collini, M.D., et al, Tetrahedron Lett, 1997, 58, 7963.

Those skilled in the art will appreciate that the invention described herein in susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications which fall within the spirit and scope. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any two or more of said steps or features.

Certain embodiments of the invention will now be described with reference to the following examples which are intended for the purpose of illustration only and are not intended to limit the scope of the generality hereinbefore described.

Examples

Table 1 summarises the effects of certain 2-aminothiophenes.

The allosteric score (0-100%) is a measure of the maximum allosteric effect of each compound in preventing orthosteric radioligand dissociation. The potency (ED5o) of each compound as an allosteric enhancer, and orthosteric antagonist activities for each compound are also reported. In order to calculate the maximum score (Max in Table 1) and the ED50, we fit a dose response curve of enhancer score vs. enhancer concentration to a 4 parameter logistic equation using Graphpad Prism™ software. From the fit to these curves we calculate the ED50 of each AE, as a measure of potency, and the theoretical maximum score that would occur upon saturation of the AE binding site, a measure of maximum allosteric efficacy. In cases in which the ED5O of the AE is > 10 μM we could not accurately determine the maximum response, so we approximated the maximum response by the response measured at the highest dose of AE tested, 50 μM. In a practical sense the overall activity of an AE at a given dose depends on both its potency and efficacy - with the greatest activity by AE with low ED50 and high maximal response. The influence of the substituent in the 5-position on AE activity was evaluated in two series, where Z is phenyl and ethoxy. During this study, in the first series (where Z = Ph), the analog with no 5- substitutent (compound Example 1) proved to be the most effective allosteric enhancer with an AE score of nearly 77%. A range of substituted phenyl groups in the 5-position were also evaluated and all of these compounds had modest maximal AE scores ranging from 5 - 24%.

Table 1

Example/Reference Z Q Max AE Enhancer %

Example No. Score ED50 (μM) Inhibition*

±SEM

1 Ph H 76.8±8.5 15.8±2.8 61.1±2.0

2 OEt 4-ClPh 57.0±5.8 6.6±1.9 58.4±2.3

Ref l OEt H 7.8±0.7 9.4±1.5 93.0±3.2

Ref 2 Ph Ph 18.1±0.4 2.3±0.8 82.4±2.2 Example/Reference Z Q Max AE Enhancer %

Example No. Scoref ED50 (μM) Inhibition*

±SEM

Ref 3 Ph 3-AcPh 18.5±1.7 >10 33.1±2.0

Ref 4 Ph 4-AcPh 4.8±0.5 >10 25.6±6.8

Ref 5 Ph 4-NO2Ph 23.7±0.7 >10 34.8±1.4

Ref 6 Ph 4-ClPh 22.5±2.9 >10 59.1±0.4

Ref 7 Ph 4-MeOPh 7.4±0.8 >10 65.2±1.6

Ref 8 OEt Ph 13.2±0.7 >10 83.6±1.7

Ref 9 OEt 3-AcPh 14.4±1.5 >10 68.9±0.5

Ref lO OEt 4-AcPh 28.5±2.9 >10 64.6±1.8

Ref ll OEt 4-NO2Ph 10.3±1.7 >10 71.4±21.1

Ref l2 OEt 4-MeOPh 17.5±0.2 >10 81.5±3.8

Ref l3 OEt 4-CF3Ph 14.8±1.0 >10 48.5±4.6

Ref l4 OEt 4-pyridyl O >10 91.0±0.1

Ref l5 Ph Cl 22.2±1.8 >10 87.1±2.6

Ref lό Ph Br 53.5±2.2 >10 47.5±0.9

PD (I) 28±1.1 13.6±2.1 18.8±2.5

* For compounds with an ED50 < 10 μM this value is based on curve fitting relating AE score to AE concentration using the equation Score=ScoreMax*[AE]/(ED50 + [AE]). Data points are the mean ± sem, N=2-3. For compounds with ED5O values > 10 μM the score at 50 μM is recorded. *Orthosteric antagonistst activity, % Inhibition of specific [3H]CPX binding by 10 μM allosteric enhancer, N=3.

To further validate the functional relevance of the allosteric properties we identified in the binding assays, the most active compound (Example 1) was more rigorously characterized in a cell-based signalling assay of adenosine Ai receptor-mediated ERK1/2 phosphorylation. Figure 1 shows the results of these experiments, where it can be seen that Example 1 caused a concentration-dependent enhancement of the effects of the orthosteric agonist, R-PIA, in a recombinant cell line stably expressing the human A1 receptor. The curves superimposed on the datasets represent the best fit of an allosteric receptor model (Leach et al, Trends Pharmacol ScI 2007, 28, 382-389, which quantifies the effects of the enhancer in terms of two parameters: KB, the enhancer's dissociation constant for binding to the free receptor, and a "cooperativity factor" (CF), which quantifies the magnitude of the allosteric effect exerted by the modulator on the orthosteric agonist. CF values greater than 1 (or LogCF values greater than 0) denote allosteric enhancement, whereas CF values less than 1 (LogCF less than 0) denote allosteric inhibition. The estimated value of LogKβ = -6.39 means that the dissociation constant of Example 1 for the A1 allosteric site is approx. 0.4 μM, whereas LogCF of 0.39 implies an approx. allosteric 3-fold enhancement of agonist potency.

A contrasting situation was observed for the second series of compounds comprised of ethyl 2-amino-4-(3-trifluoromethylphenyl)thiophene-3-carboxylates (Z = OEt). In this series, the analog with no substituent in the 5-position (Reference Example 1) was less effective than most of the 5-phenylthiophenes that were evaluated (Reference Examples 2-6). The most efficacious and potent AE in this series was Example 2 which possessed a 4-chlorophenyl group in the 5-position (AE score = 57%, ED50 = 6.6 μM). The other 5- phenyl compounds had only modest AE scores ranging from 10 - 29%. Ethyl 2-amino-4- (3-(trifluoromethyl)phenyl)thiophene-3-carboxylate (reference Example 1) had a AE score of only 8% while the 5-pyridyl analog (Reference Example 14) was inactive at the test concentration.

All of these compounds have activity as orthosteric antagonists, although there was a wide variation in the ratio of AE activity to antagonist activity. For example, Reference Example 14 had an AE score of 0% and showed 91% inhibition of [ H]CPX binding while compound Example 1 had an AE score of 77% and at lOμM showed 61% inhibition of [3H]CPX binding.

1. Chemistry Experimental Melting points were determined with an Electrothermal melting point apparatus and are uncorrected. All NMR spectra were recorded on a Bruker Avance DPX 300 spectrometer. 1H and 13C NMR spectra were recorded at 300.13 and 75.4 MHz, respectively, and, unless stated otherwise, samples were dissolved in CDCl3. Thin-layer chromatography was conducted on 0.2 mm plates using Merck silica gel 60 F254. Column chromatography was achieved using Merck silica gel 60 (particle size 0.063-0.200 μm, 70-230 mesh).

General Protocol A:

(i) Substituted benzoylacetonitrile, TiCl4, pyridine, CH2Cl2; (ii) sulphur, Et2NH, THF.

The appropriate benzoylacetonitrile (3 mmol) and acetophenone (3.3 mmol) were dissolved in dry dichloromethane (12 mL) in a two neck flask in an N2 atmosphere and cooled to 0 0C with an ice bath. To the cooled solution was added dropwise neat TiCl4 (3.3 mmol, 362 μL). After approximately 10-30 minutes dry pyridine (215 μL) was added dropwise and the ice bath was removed. After 1 hr a further aliquot of dry pyridine (644 μL) is added dropwise and left to stir at room temperature overnight, The mixture is diluted with 2M HCl (30 mL) and the organic phase separated. The aqueous phase is extracted with dichloromethane (2 x 30 mL) and the combined organics were washed with water then brine, dried over MgSO4, filtered and concentrated to a resin. The resin was taken up in THF (6 mL) and elemental sulphur (3.3 mmol, 106 mg) was added followed by Et2NH (610 μL) and stirred at room temperature for 18 hr. The mixture is diluted with ethyl acetate and washed with water (x 2), then brine, dried over MgSO4, filtered and concentrated to a resin. The resin is chromatographed on silica gel eluting with 10-30% ethyl acetate, petroleum ether (40-60 0C), providing after concentration of the appropriate fractions a solid that is recrystallised from isopropanol, ethyl acetate or petroleum ether. (2-amino-4-(3-(trifluoromethyl)phenyI)thiophen-3-yI)(phenyI)methanone (Example 1)

Prepared by General Protocol A:

Yield 33%. Mp 139-141 0C. 1H NMR δ 7.29-7.26 (m, 2H, aromatic), 7.21-7.18 (m, 3H5 aromatic), 7.13-7.06 (m, 2H, aromatic), 7.00-6.95 (m, 2H, aromatic), 6.6 (bs, 2H, NH2), 6.21 (bs, IH, 5-H). 13C NMR δ 192.68, 166.34, 140.25, 139.87, 138.04, 131.45, 130.68, 130.23, 130.02, 129.81, 129.60, 128.63, 128.15, 127.42, 126.52, 125.40, 125.38, 124.71, 123.06, 123.04, 122.91, 121.10, 114.63, 106.37. HR-ESMS calcd for Ci8Hi3F3NOS+ (M+l) 348.0664, found 348.0660.

(2-amino-4-phenylthiophen-3-yl)(4-chlorophenyl)methanone (Example 3)

Prepared by General Protocol A:

Yield 24%. M.p 144-145 °C. 1H NMR δ 7.24 (d, J= 8.4 Hz, 2H, aromatic), 7.02-6.97 (m, 5H, aromatic), 6.94 (d, J = 8.4 Hz, 2H, aromatic), 6.59 (bs, 2H, NH2), 6.18 (s, IH, 5-H). 13C NMR δ 191.42, 166.30, 141.51, 138.39, 137.03, 136.54, 130.20, 128.53, 127.82, 127.45, 126.66, 114.76, 105.56. HR-ESMS calcd for C17Hi3ClNOS+ (M+l) 314.0401, found 314.0407.

(2-amino-4-(3-chlorophenyl)thiophen-3-yl)(4-chlorophenyl)methanone (Example 4)

Prepared by General Protocol A:

Yield 8%. 1H NMR δ 7.27-7.22 (m, 2H, aromatic), 7.03-6.87 (m, 6H, aromatic), 6.67 (bs,

2H5 NH2), 6.21 (s, IH, 5-H). 13C NMR δ 191.27, 166.35, 139.95, 138.69, 138.40, 136.70, 133.60, 129.84, 129.04, 128.70, 127.59, 126.60, 126.57, 114.47, 106.21. HR-ESMS calcd for C17Hi2Cl2NOS+ (M+l) 348.0011, found 348.0022.

(2-amino-4-(4-chlorophenyl)thiophen-3-yl)(4-chlorophenyI)methanone (Example 5)

Prepared by General Protocol A:

Yield 10%. 1H NMR δ 121-122 (m, 2H, aromatic), 7.04-6.90 (m, 6H, aromatic), 6.61 (bs, 2H5 NH2), 6.18 (s, IH, 5-H). 13C NMR <5 191.19, 166.16, 140.19, 138.21, 136.96, 135.54, 132.68, 130.14, 129.63, 127.93, 127.62, 114.61, 105.89. HR-ESMS calcd for CI7HI2CI2NOS+ (M+l) 348.0011, found 348.0020.

(2-amino-4-(4-bromophenyl)thiophen-3-yl)(4-chlorophenyl)methanone (Example 6)

Prepared by General Protocol A: Yield 21%. 1H NMR δ 124 (d, J = 8.7 Hz5 2H5 aromatic), 7.15 (d, J = 8.4 Hz, 2H5 aromatic), 7.02 (d, J= 8.4 Hz, 2H5 aromatic), 6.86 (d, J= 8.4 Hz5 2H5 aromatic), 6.62 (bs, 2H, NH2), 6.18 (s, IH, 5-H). 13C NMR (4:1 CDCl3^6DMSO) δ 194.72, 172.91, 144.23, 143.74, 141.28, 140.68, 135.42, 135.37, 134.92, 132.19, 132.15, 124.81, 117.59, 110.54, 110.50. HR-ESMS calcd for Ci7Hi2BrClNOS+ (M+l) 391.9506, found 391.9508.

(2-amino-4-(3-bromophenyl)thiophen-3-yl)(4-chlorophenyl)methanone (Example 7)

Prepared by General Protocol A:

Yield 4%. M.p 210-212 °C. 1H NMR δ 7.23 (d, J = 8.4 Hz, 2H, aromatic), 7.18-7.14 (m, IH, aromatic), 7.10-7.09 (m, IH, aromatic), 7.02 (d, J = 8.4 Hz, 2H, aromatic), 6.97-6.86 (m, 2H, aromatic), 6.68 (bs, 2H, NH2), 6.20 (s, IH, 5-H). 13C NMR δ 191.29, 166.33, 139.85, 138.91, 138.39, 136.70, 131.69, 129.79, 129.52, 129.29, 127.62, 126.95, 121.78, 114.47, 106.21. HR-ESMS calcd for Ci7H12BrClNOS+ (M+l) 391.9506, found 391.9516.

(2-amino-4-(2-fluorophenyl)thiophen-3-yl)(4-chlorophenyl)methanone (Example 8)

Prepared by General Protocol A:

Yield 3%. 1H NMR δ 7.25 (d, J = 9.0 Hz, 2H3 aromatic), 7.15-6.88 (m, 5H, aromatic), 6.63 (bs, 2H, NH2), 6.60-6.56 (m, IH, aromatic), 6.25 (s, IH, 5-H). 13C NMR δ 191.51, 165.37, 160.29, 157.02, 138.15, 136.45, 134.56, 130.54, 130.50, 129.92, 129.07, 128.96, 127.21, 123.84, 123.80, 115.29, 115.00, 107.20. HR-ESMS calcd for CI7HI2CIFNOS+ (M+l) 332.0307, found 332.0298.

(2-amino-4-(3-fluorophenyl)thiophen-3-yl)(4-chlorophenyl)methanone (Example 9)

Prepared by General Protocol A:

Yield 18%. 1H NMR δ 7.26 (d, J = 8.4 Hz, 2H, aromatic), 7.01 (d, J = 8.4 Hz, 2H, aromatic), 6.98-6.70 (m, 3H, aromatic), 6.63 (bs, 2H, NH2), 6.22 (s, IH5 5-H). 13C NMR δ 191.22, 166.29, 162.97, 161.34, 140.16, 139.19, 139.14, 138.41, 136.76, 129.98, 129.36 , 129.30, 127.58, 124.30, 115.41, 115.27, 114.49, 113.52, 113.38, 106.21. HR-ESMS calcd for C17Hi2ClFNOS+ (M+l) 332.0307, found 332.0299.

(2-amino-4-(4-fluorophenyl)thiophen-3-yl)(4-chlorophenyl)methanone (Example 10)

Prepared by General Protocol A:

Yield 7%. 1H NMR δ 124 (d, J = 8.7 Hz, 2H, aromatic), 7.01 (d, J = 8.4 Hz, 2H, aromatic), 6.98-6.94 (m, 2H, aromatic), 6.74-6.69 (m, 2H, aromatic), 6.60 (bs, 2H, NH2), 6.15 (s, IH, 5-H). 13C NMR δ 191.27, 166.20, 162.46, 160.83, 140.29, 138.28, 136.80, 133.19, 130.18, 130.00, 129.95, 127.56, 114.80, 114.73, 114.65, 105.54. HR-ESMS calcd for CI7HI2CIFNOS+ (M+l) 332.0307, found 332.0299.

(2-amino-4-(4-nitrophenyl)thiophen-3-yl)(4-chlorophenyl)methanone (Example 11)

Prepared by General Protocol A:

Yield 13%. 1H NMR δ 7.91-7.82 (m, 2H5 aromatic), 7.34-7.32 (m, IH, aromatic), 7.25- 7.17 (m, 3H, aromatic), 6.96 (d, J= 8.7 Hz, 2H, aromatic), 6.77 (bs, 2H, NH2), 6.30 (s, IH, 5-H). 13C NMR (4:1 CDCl3^6DMSO) δ 188.62, 167.27, 144.60, 143.09, 137.86, 137.55, 135.22, 129.00, 127.94, 126.51, 121.76, 111.51, 106.97. HR-ESMS calcd for Ci7H12ClN2O3S+ (M+l) 359.0252, found 359.0267.

(2-amino-4-(3-nitrophenyl)thiophen-3-yl)(4-chlorophenyl)methanone (Example 12)

Prepared by General Protocol A:

Yield 5%. 1H NMR δ 7.90 (d, J = 8.7 Hz, 2H, aromatic), 7.27 (d, J = 8.4 Hz, 2H, aromatic), 7.16 (d, J= 9.0 Hz, 2H, aromatic), 7.01 (d, J= 8.4 Hz, 2H, aromatic), 6.67 (bs, 2H, NH2), 6.32 (s, IH, 5-H). ). 13C NMR δ 190.87, 166.73, 147.47, 138.82, 138.61, 138.31, 136.89, 134.09, 129.97, 128.76, 127.70, 123.38, 121.30, 114.12, 107.24. HR- ESMS calcd for C17Hi2ClN2O3S+ (M+ 1) 359.0252, found 359.0267.

(2-amino-4-(3-methoxyphenyl)thiophen-3-yI)(4-chlorophenyl)methanone (Example 13)

Prepared by General Protocol A:

Yield 12%. 1H NMR δ 7.26 (d, J = 7.5 Hz5 2H, aromatic), 6.98 (d, J = 7.8 Hz, 2H, aromatic), 6.95-6.92 (m, IH, aromatic), 6.65-6.56 (m, 4H, aromatic and NH2), 6.49-6.48 (m, IH, aromatic), 6.21 (s, IH, 5-H), 3.65 (s, 3H, OMe). 13C NMR δ 191.41, 166.10, 158.90, 141.32, 138.50, 138.33, 136.55, 129.95, 128.95, 127.44, 121.16, 114.82, 114.32, 112.41, 105.59, 55.14. HR-ESMS calcd for Ci8H15ClNO2S+ (M+l) 344.0507, found 344.0515.

(2-amino-4-(4-methoxyphenyl)thiophen-3-yI)(4-chlorophenyl)methanone (Example 14)

Prepared by General Protocol A:

Yield 9%. 1H NMR δ 12A (d, J = 8.4 Hz3 2H, aromatic), 6.98 (d, J = 8.4 Hz, 2H, aromatic), 6.90 (d, J = 8.7 Hz, 2H, aromatic), 6.60 (bs, 2H5 NH2), 6.55 (d, J = 8.7 Hz, 2H, aromatic), 6.12 (s, IH, 5-H), 3.71 (s, 3H, OMe). 13C NMR δ 191.50, 166.10, 158.51, 141.06, 138.36, 136.44, 131.64, 130.21, 129.65, 127.40, 114.92, 113.36, 104.55, 55.37. HR-ESMS calcd for Ci8Hi5ClNO2S+ (M+ 1) 344.0507, found 344.0518.

(2-amino-4-(4-iodophenyl)thiophen-3-yl)(4-chlorophenyl)methanone (Example 15)

Prepared by General Protocol A:

Yield 11%. 1H NMR δ 7.35 (d, J = 8.4 Hz, 2H, aromatic), 7.22 (d, J = 8.4 Hz, 2H, aromatic), 7.01 (d, J= 8.4 Hz, 2H, aromatic), 6.72 (d, J= 8.4 Hz, 2H, aromatic), 6.65 (bs, 2H5 NH2), 6.18 (s, IH5 5-H). 13C NMR δ 191.18, 166.23, 140.31, 138.19, 137.00, 136.85, 136.59, 130.23, 130.08, 127.65, 114.47, 105.85, 92.01. HR-ESMS calcd for C17H12ClINOS+ (M+l) 439.9367, found 439.9382.

(2-amino-4-(3-(trifluoromethyl)phenyl)thiophen-3-yl)(4-chlorophenyl)methanone (Example 16)

Prepared by General Protocol A: Yield 7%. 1H NMR δ 7.30-7.27 (m, IH5 aromatic), 7.23-7.13 (m, 5H, aromatic), 6.96 (d, J = 8.1 Hz, 2H, aromatic), 6.73 (bs, 2H, NH2), 6.24 (s, IH, 5-H). 13C NMR (75.4 MHz) δ 191.22, 166.53, 140.01, 138.32, 137.91, 136.84, 131.51, 130.83, 130.41, 130.01, 129.55, 129.19, 128.43, 127.67, 125.59, 125.55, 123.32, 123.28, 121.98, 118.37, 114.57, 106.53. HR-ESMS calcd for C18Hi2ClF3NOS+ (M+l) 382.0275, found 382.0278.

(2-amino-4-(3,5-bis(trifluoromethyl)phenyl)thiophen-3-yI)(4-chlorophenyl)methanone (Example 17)

Prepared by General Protocol A:

Yield 8%. 1H NMR δ 7.54 (bs, IH, aromatic), 7.42 (bs, 2H, aromatic), 7.17 (d, J- 8.4 Hz, 2H, aromatic), 6.97 (d, J = 8.4 Hz, 2H, aromatic), 6.83 (bs, 2H, NH2), 6.31 (s, IH, 5-H). 13C NMR (75.4 MHz) δ 190.87, 166.97, 139.25, 139.41, 138.16, 137.13, 131.88, 131.44, 130.99, 130.55, 129.87, 128.50, 127.87, 124.80, 121.19, 120.22, 120.17, 120.13, 117.57, 114.21, 107.60. HR-ESMS calcd for C19Hn ClF6NO S+ (M+H) 450.0149, found 450.0163.

(2-amino-4-phenylthiophen-3-yI)(phenyl)methanone (Example 18)

Prepared by General Protocol A: Yield 30%. 1H NMR δ 7.34-7.32 (m, 2H, aromatic), 7.15-7.09 (m, IH, aromatic), 7.02- 6.92 (m, 7H, aromatic), 6.55 (bs, 2H, NH2), 6.19 (s, IH, 5-H). 13C NMR δ 192.93, 165.72, 141.84, 139.96, 137.25, 130.57, 128.85, 128.49, 127.64, 127.26, 126.42, 115.09, 105.45. HR-ESMS .calcd for Ci7Hi4NOS+ (M+l) 280.0791, found 280.0792.

(2-amino-4-(2-fluorophenyl)thiophen-3-yl)(phenyl)methanone (Example 19)

Prepared by General Protocol A:

Yield 23%. 1H NMR δ 7.34-7.32 (m, 2H, aromatic), 7.14-7.09 (m, 2H, aromatic), 7.03- 6.83 (m, 4H, aromatic), 6.60-6.54 (m, 3H3 aromatic and NH2), 6.25 (s, IH, 5-H). 13C NMR δ 192.94, 165.19, 159.44, 157.81, 139.70, 134.73, 130.51, 130.50, 130.41, 128.78, 128.72, 128.56, 127.02, 125.59, 125.49, 123.59, 115.03, 114.99, 114.89, 107.09. HR-ESMS calcd for CnH13FNOS+ (M+l) 298.0696, found 298.0698.

(2-amino-4-(3-fluorophenyl)thiophen-3-yl)(phenyl)methanone (Example 20)

Prepared by General Protocol A:

Yield 32%. 1H NMR δ 7.34-7.32 (m, 2H, aromatic), 7.19-7.14 (m, IH, aromatic), 7.07- 7.02 (m, 2H, aromatic), 6.95-6.88 (m, IH, aromatic), 6.79-6.62 (m, 3H, aromatic), 6.59 (bs, 2H, NH2), 6.21 (s, IH, 5-H). 13C NMR δ 192.72, 165.86, 162.90, 161.28, 140.50, 140.00, 139.41, 139.35, 130.74, 129.12, 129.07, 128.63, 127.39, 124.28, 124.26, 115.36, 115.22, 114.82, 113.31, 113.17, 106.10. HR-ESMS calcd for Ci7H13FNOS+ (M+l) 298.0696, found 298.0695.

(2-amino-4-(4-fluorophenyl)thiophen-3-yl)(phenyl)methanone (Example 21)

Prepared by General Protocol A:

Yield 29%. 1H NMR δ 7.31-7.25 (m, 2H, aromatic), 7.20-7.13 (m, IH, aromatic), 7.05-

6.92 (m, 4H, aromatic), 6.69-6.60 (m, 2H, aromatic), 6.58 (bs, 2H, NH2), 6.14 (s, IH, 5-H). 13C NMR δ 192.81, 165.86, 162.25, 160.63, 140.63, 139.86, 133.37, 130.69, 129.98, 129.93, 128.78, 127.36, 115.05, 114.57, 114.42, 105.36. HR-ESMS calcd for Ci7H13FNOS+ (M+l) 298.0696, found 298.0695.

(2-amino-4-(4-bromophenyl)thiophen-3-yl)(phenyl)methanone (Example 22)

Prepared by General Protocol A:

Yield 18%. 1H NMR δ 1.31-126 (m, 2H, aromatic), 7.22-7.17 (m, IH, aromatic), 7.10- 7.01 (m, 4H, aromatic), 6.86 (d, J= 8.4 Hz, 2H, aromatic), 6.59 (bs, 2H, NH2), 6.17 (s, IH, 5-H). 13C NMR (75.4 MHz) δ 192.74, 166.20, 140.54, 139.91, 136.28, 130.79, 130.72, 130.01, 128.82, 127.51, 120.43, 114.69, 105.82. HR-ESMS calcd for C]7H13BrNOS+ (M+l) 357.9896, found 357.9899.

(2-amino-4-(3-bromophenyl)thiophen-3-yl)(phenyI)methanone (Example 23)

Prepared by General Protocol A:

Yield 14%. 1H NMR δ 7.33-7.28 (m, 2H, aromatic), 7.19-7.13 (m, 2H, aromatic), 7.09- 7.03 (m, 3H, aromatic), 6.96-6.92 (m, IH, aromatic), 6.85-6.80 (m, IH, aromatic), 6.63 (bs, 2H, NH2), 6.20 (s, IH, 5-H). 13C NMR δ 192.77, 165.94, 140.18, 139.96, 139.13, 131.58, 130.73, 129.34, 129.09, 128.50, 127.43, 126.94, 121.63, 114.76, 106.13. HR- ESMS calcd for Ci7Hi3BrNOS+ (M+l) 357.9896, found 357.9899.

(2-amino-4-(3-chlorophenyl)thiophen-3-yl)(phenyϊ)methanone (Example 24)

Prepared by General Protocol A:

Yield 30%. 1H NMR δ 133-125 (m, 2H, aromatic), 7.19-7.14 (m, IH, aromatic), 7.07- 6.98 (m, 3H5 aromatic), 6.95-6.87 (m, 3H, aromatic), 6.62 (bs, 2H, NH2), 6.20 (s, IH, 5-H). 13C NMR δ 192.77, 166.02, 140.27, 140.00, 138.93, 133.41, 130.71, 128.83, 128.61, 128.53, 127.40, 126.56, 126.42, 114.70, 106.09. HR-ESMS calcd for C17Hi3ClNOS+ (M+l) 314.0401, found 314.0403.

(2-amino-4-(4-chlorophenyl)thiophen-3-yl)(phenyI)methanone (Example 25)

Prepared by General Protocol A:

Yield 38%. 1H NMR δ 7.32-7.29 (m, 2H, aromatic), 7.22-7.17 (m, IH, aromatic), 7.06- 7.01 (m, 2H, aromatic), 6.93 (s, 4H, aromatic), 6.59 (bs, 2H, NH2), 6.17 (s, IH, 5-H). 13C NMR (75.4 MHz) δ 192.78, 166.12, 140.53, 139.91, 135.83, 132.27, 130.79, 129.68, 128.83, 127.78, 127.49, 114.78, 105.81. HR-ESMS calcd for CI7HI3CINOS+ (M+l) 314.0401, found 314.0404.

(2-amino-4-(4-iodophenyI)thiophen-3-yl)(phenyl)methanone (Example 26)

Prepared by General Protocol A:

Yield 40%. 1H NMR δ 1.30-1.21 (m, 4H, aromatic), 7.23-7.18 (m, IH, aromatic), 7.06- 7.01 (m, 2H, aromatic), 6.73 (d, J= 8.1 Hz, 2H, aromatic), 6.60 (bs, 2H, NH2), 6.17 (s, IH5 5-H). 13C NMR ^ 192.71, 166.07, 140.60, 139.84, 136.79, 136.62, 130.68, 130.18, 128.75, 127.46, 114.66, 105.74, 91.84. HR-ESMS calcd for C17H13INOS+ (M+l) 405.9757, found 405.9767.

(2-amino-4-(4-methoxyphenyl)thiophen-3-yl)(phenyl)methanone (Example 27)

Prepared by General Protocol A:

Yield 9%. 1H NMR δ 7.32 (d, J = 7.5 Hz, 2H, aromatic), 7.17-7.12 (m, IH, aromatic), 7.04-6.98 (m, 2H, aromatic), 6.94-6.91 (m, 2H, aromatic), 6.52-6.49 (m, 4H, aromatic and NH2), 6.12 (s, IH, 5-H), 3.67 (s, 3H, OMe). 13C NMR δ 193.00, 165.72, 158.16, 141.35, 139.93, 130.53, 129.95, 129.57, 128.88, 127.26, 115.16, 113.16, 104.46, 55.22. HR-ESMS calcd for C18H16NO2S+ (M+l) 310.0896, found 310.0901.

(2-amino-4-(3-methoxyphenyl)thiophen-3-yl)(phenyl)methanone (Example 28)

Prepared by General Protocol A:

Yield 24%. 1H NMR δ 7.37-7.34 (m, 2H, aromatic), 7.18-7.13 (m, IH, aromatic), 7.05- 6.99 (m, 2H, aromatic), 6.94-6.89 (m, IH, aromatic), 6.69-6.66 (m, IH, aromatic), 6.58 (bs, 2H, NH2), 6.53-6.50 (m, 2H, aromatic), 6.21 (s, IH, 5-H), 3.62 (s, 3H, OMe). 13C NMR δ 192.87, 165.87, 158.76, 141.61, 140.10, 138.61, 130.64, 128.76, 128.69, 127.28, 121.09, 114.99, 113.77, 112.77, 105.53, 55.06. HR-ESMS calcd for C18H16NO2S+ (M+l) 310.0896, found 310.0898.

(2-amino-4-(3-nitrophenyl)thiophen-3-yl)(phenyl)methanone (Example 29)

Prepared by General Protocol A:

Yield 19%. 1H NMR δ 7.83-7.79 (m, 2H, aromatic), 7.34-7.30 (m, 2H, aromatic), 7.16- 7.07 (m, 3H, aromatic), 7.01-6.98 (m, 2H, aromatic), 6.76 (bs, 2H, NH2), 6.28 (s, IH, 5-H). 13C NMR δ 192.39, 166.52, 147.34, 139.93, 139.14, 138.79, 134.12, 130.73, 128.55, 128.51, 127.49, 123.40, 121.16, 114.34, 107.04. HR-ESMS calcd for CnHi3N2O3S+ (M+ 1) 325.0641, found 325.0642.

(2-amino-4-(4-nitrophenyl)thiophen-3-yl)(phenyl)methanone (Example 30)

Prepared by General Protocol A:

Yield 22%. 1H NMR δ 7.84 (d, J = 8.7 Hz, 2H, aromatic), 7.33-7.30 (m, 2H, aromatic), 7.17-7.13 (m, 3H, aromatic), 7.05-6.99 (m, 2H, aromatic), 6.69 (bs, 2H, NH2), 6.31 (s, IH, 5-H). ). 13C NMR (3:2 CDCl3:d6DMSO) δ 189.85, 166.67, 144.24, 143.01, 139.15, 137.65, 129.16, 127.64, 127.26, 126.15, 121.34, 111.43, 106.57. HR-ESMS calcd for Ci7Hi3N2O3S+ (M+l) 325.0641, found 325.0642.

(2-amino-4-(3,5-bis(trifluoromethyl)phenyl)thiophen-3-yl)(phenyl)methanone (Example 31)

Prepared by General Protocol A:

Yield 4%. 1H NMR δ 7.44-7.42 (m, 3H, aromatic), 7.26-7.23 (m, 2H, aromatic), 7.15-7.10

(m, IH, aromatic), 7.02-6.97 (m, 2H, aromatic), 6.80 (bs, 2H, NH2), 6.29 (s, IH, 5-H). 13C NMR (75.4 MHz) δ 192.38, 166.62, 139.75, 139.39, 138.76, 131.60, 131.16, 130.91, 130.72, 130.28, 128.54, 128.43, 127.66, 124.84, 121.23, 120.09, 120.05, 120.00, 117.61, 114.40, 107.42. HR-ESMS calcd for Ci9Hi2F6NOS+ (M+l) 416.0544, found 416.0545.

(5)

(iv)

(iii) BoC2O5 DMAP, dioxane; (iv) NBS, AcOH/CH2Cl2; (v) Method A: R6B(OH)2, 3 mol% Pd[P(Ph)3J4, K3PO4, DMFVH2O or Method B: R6B(OH)2, 3 mol% Pd(PPh3)2Cl2, K3PO4, toluene/H2O, boronic acid, 150 0C MW; (vi) TFA, CH2Cl2 or 6M HCl, EtOH.

Ethyl 2-Amino-4-(3-(trifluoromethyl)phenyl)thiophene-3-carboxylate (Reference Example 1)

3'-(Trifluoromethyl)acetophenone (0.8 mL, 5.32 mmol) and ethyl cyanoacetate (0.77 mL, 6.42 mmol) were dissolved in dry CH2Cl2 (25 mL) in a three necked flask, fitted with a rubber septum and flushed with N2 gas. The solution was cooled to 0 °C with an ice bath and neat TiCl4 (1.17 mL, 10.64 mmol) was added in a dropwise fashion. Pyridine (360 μL) was added after 10 min. After the addition was complete, the ice bath was removed and the solution left to stir at room temperature. After 30 min, another aliquot of pyridine (1.08 mL) was added dropwise and stirring was continued overnight. The mixture was diluted with EtOAc (150 mL) and washed with 2M HCl (2 x 100 mL), H2O (200 mL) and finally with brine. The organic layer was dried (MgSO4), filtered and evaporated to provide 1.49 g of yellow resin that slowly solidified. The resin was taken up in dry THF (10 niL) and elemental sulphur (200 mg) was added followed by N5N-diethylamine (2 mL) and the solution was stirred at room temperature for 1.5 h. The reaction mixture was then diluted with water and extracted with CH2Cl2 (3 x 50 mL). The combined organic extracts were washed with water and then brine, dried (MgSO4), filtered and evaporated to dryness. The crude product was chromatographed on silica gel eluting with EtOAcφet ether (15:85), providing a pale yellow resin that solidified upon standing (1.52 g, 91%). Mp 65-66 0C. 1H NMR δ 7.58-7.40 (m, 4H, aromatic), 6.14 (bs, 2H, NH2), 6.09 (s, IH, 5-H), 4.04 (q, J= 7.2 Hz, 2H, CH2CH3), 0.89 (t, J= 7.2 Hz, 3H, CH2CH3). MS (APCI): m/z = 316.2 (100%) (M + H)+. HR-MS (ESI) calcd for C14H13F3NO2S+ (M+l) 316.0614, found 316.0611.

[2-Amino-4-(3-(trifluoromethyl)phenyl)thiophen-3-yI]phenyl methanone (Example 1)

3'-(Trifluoromethyl)acetophenone (3 mL, 3.71 g, 19.69 mmol) and benzoylacetonitrile (3.00 g, 20.67 mmol) were dissolved in dry CH2Cl2 (75 mL) in a three necked flask, fitted with a rubber septum and flushed with N2 gas. The solution was cooled to 0 °C with an ice bath and neat TiCl4 (4.6 mL, 42.27 mmol) was added in a dropwise fashion. Pyridine (1.41 mL) was added after 10 min. After the addition was complete, the ice bath was removed and the solution left to stir at room temperature. A further aliquot of pyridine (4.23 mL) was added after 1 h and the reaction mixture was stirred overnight. The reaction mixture was diluted with EtOAc (250 mL) and washed with 2M HCl (2 x 200 mL), H2O (300 mL) and finally with brine. The organic layer was dried (MgSO4), filtered and evaporated to provide an orange resin (7.42 g). This resin was dissolved in dry THF (40 mL), elemental sulphur (667 mg) and JV,iV-diethylamme (4 mL) were added and the reaction was stirred at room temperature overnight. The solution was diluted with water and extracted with CH2Cl2 (3 x 100 mL). The combined organic extracts were washed with water and then brine, dried (MgSO4), filtered and concentration to a red/brown residue (8.03 g). The crude product was chromatographed on silica gel eluting with EtOAc :pet ether (20:80), supplying an orange resin that was triturated with ,sec-butanol/H2O (80/20) to afford orange crystals (1.81 g, 26%). Mp 135-138 0C. 1H NMR δ 7.29-7.26 (m, 2H, aromatic), 7.21-7.18 (m, 3H, aromatic), 7.13-7.06 (m, 2H, aromatic), 7.00-6.95 (m, 2H, aromatic), 6.6 (bs, 2H, NH2), 6.21 (bs, IH, 5-H). MS (APCI): m/z = 348.1 (100%) (M + H)+. HR-MS (ESI) calcd for Ci8H13F3NOS+ (M+l) 348.0664, found 348.0660.

Ethyl 5-Bromo-2-(tert-butoxycarbonylamino)-4-(3-

(trifluoromethyl)phenyl)thiophene-3-carboxylate (Intermediate A) Reference Example 1 (3.84 g, 12.18 mmol) was dissolved in dioxane (45 mL) and BoC2O (2.79 g, 12.79 mmol) was added to the solution followed by DMAP (148 mg, 10 mol%). The homogeneous solution was heated on an oil bath at 70 -80 0C for 2 h. After cooling, the solution was diluted with ether and washed with water (x 2) and then brine. The organic layer was dried (MgSO4), filtered and evaporated to give a reddish brown oil (4.9 g). This oil was chromatographed on silica gel column using EtOAc.-pet ether (5:95) as an eluent to afford a clear colourless resin (2.27 g, 45%). The resin (1.93 g, 4.65 mmol) was dissolved in 25 mL of CH2Cl2:Ac0H (1 :1) and cooled in an ice salt bath (~ -16 to -18 0C). NBS (0.91 g, 5.11 mmol) was added and the reaction mixture was stirred for 0.5 h on an ice/salt bath. The solution was diluted with water (200 mL) and extracted with ether. The organic phase was washed with saturated NaHCO3 solution (until gas evolution ceased) and finally with brine. The organic layer was dried (MgSO4), filtered from insoluble material and concentrated to a solid, that was recrystallised from MeOH/H2O (95/5), to afford a white solid (2.2 g, 96%). 1H NMR δ 10.43 (bs, IH, NH), 7.63-7.61 (m, IH, aromatic), 7.53-7.48 (m, 2H, aromatic), 7.41-7.39 (m, IH, aromatic), 3.95 (q, J = 7.2 Hz, 2H, C//2CH3), 1.49 (bs, 9H, C(CH3)3), 0.78 (t, J = 7.2 Hz, 3H, CH2CH3). MS (APCI): m/z = 492.0 (48%), 494.0 (100%) (M H)-. HR-MS (ESI) calcd for Ci9Hi9BrF3NNaO4S+ (M+Na) 516.0062, found 516.0070.

[5-Bromo-2-(tert-butoxycarbonylamino)-4-(3-(trifluoromethyl)phenyl)thiophen-3- yl] phenyl methanone (Intermediate B)

Example 1 (1.00 g, 2.88 mmol) was dissolved in dioxane (20 mL) and Boc2O (0.66 g, 3.02 mmol) was added to the solution followed by DMAP (35 mg, 10 mol%). The homogeneous solution was heated on an oil bath at 70 to 80 0C for 2 h. After cooling, the solution was diluted with ether and washed with water (x 2) and then brine. The organic layer was dried (MgSO4), filtered from insoluble material and evaporated to give an orange oil (1.84 g). This oil was chromatographed on silica gel column using EtOAcφet ether (5:95) as an eluent to afford a pale yellow resin (0.75 g, 58%). The resin (494 mg, 1.10 mmol) was dissolved in 7 mL of CH2C|2:Ac0H (1 :1) and cooled in an ice salt bath (~ -16 to -18 0C). NBS (216 mg, 1.21 mmol) was added and the reaction mixture was stirred for 0.5 h on an ice/salt bath. The solution was diluted with water (100 mL) and extracted with ether. The organic phase was washed with saturated NaHCO3 solution (until gas evolution ceases) and finally with brine. The organic layer was dried (MgSO4), filtered from insoluble material and concentrated to afford a pale yellow solid. This solid was recrystallised from MeOH/H2O (95:5) resulting in a white solid (0.58 g, 99%). 1H NMR δ 10.55 (bs, IH, NH), 7.26-7.22 (m, 5H, aromatic), 7.18-7.12 (m, 2H, aromatic), 7.02-6.97 (m, 2H, aromatic), 1.53 (bs, 9H, C(CH3)3). HR-MS (ESI) calcd for C23Hi9BrF3NNaO3S+ (M+Na) 548.0113, found 548.0120.

General Protocol B:

Method A: Intermediate A or B (100 mg) was dissolved in 4:1 DMF / 2M K3PO4 (1 mL, previously sonicated for 30 min) under an atmosphere of N2. The appropriate boronic acid (1.2 eq) and Pd(PPh)3 )4 (6.6. mg, 5.70 μmol, 3 mol%) were added and the reaction was heated at 70-80 °C for 24 h. The solution was cooled and diluted with EtOAc (20 mL) and washed with water. The aqueous layer was extracted with EtOAc and the combined organics were washed with water (x 3) and finally with brine. The organic layer was dried (MgSO4), filtered from insoluble material and concentrated to a residue. The residue is filtered through a silica gel plug eluting with CHCl3 and concentrated to a residue which is subjected to silica gel chromatography.

Method B: Intermediate A or B (200 mg) was dissolved in 4:1 DMF / 2M K3PO4 (2 mL, previously sonicated for 30 min) in a sealed vial (microwave pressure tube). The appropriate boronic acid (1.2 eq) and Pd(PPh3)2Cl2 (8.0 mg, 11.40 μmol, 3 mol%) were added and the mixture was heated with stirring to 150 0C for 15 min. If the reaction was incomplete (by TLC), a further equivalent of boronic acid and 3 mol% of catalyst were added and microwave heating was continued for 10 min at 150 0C. The solution was cooled and the toluene layer was filtered through a silica plug eluting with EtOAc and finally chloroform and concentrated to a residue.

[2-Amino-5-phenyl-4-(3-trifluoromethyIphenyl)thiophen-3-yl]phenyl methanone (Reference Example 2) Method B. The residue obtained was sufficiently pure for the subsequent deprotection step. It was dissolved in CH2Cl2 (1 niL), TFA (1 mL) was added and the reaction was stirred at room temperature. After 3 h the mixture was diluted with CHCl3 (10 mL) and concentrated to give a reddish brown residue. The residue was chromatographed on a silica gel column eluting with EtOAc:pet ether (15:85), to provide a light yellow resin which slowly crystallised upon standing at 4 0C. Complete crystallisation was induced by sonicating in a minimum of methanol, to afford a yellow powder (74 mg, 45%). Mp 86-89 °C. 1H NMR δ 7.23-6.93 (m, 14H, aromatic), 3.15 (bs, 2H, NH2).

[5-(3-Acetylphenyl)-2-amino-4-(3-trifluoromethylphenyl)thiophen-3-yl]phenyl methanone (Reference Example 3)

Method A. The crude product was chromatographed on silica gel eluting with EtOAc:pet ether (5:95) to provide 40 mg of clear pale yellow resin that was triturated with MeOH / water. The resultant solid was filtered and washed with H2O providing pale yellow powder (38 mg, 35%). This cross coupled product (30 mg, 53.04 μmol) was dissolved in CH2C12 (1 mL) and TFA (400 μ L) was added at room temperature. After 1.5 h, the mixture was diluted with CHCl3 (10 mL), evaporated and chromatographed on silica gel eluting with CHCl3 to provide 26 mg of yellow resin. The resin was slowly crystallised from MeOH with careful addition of water to give a pale brown powder (15 mg, 61%). Mp 160-164 0C. 1H NMR δ 7.77-7.74 (m, IH, aromatic), 7.56 (m, IH, aromatic), 7.27-6.95 (m, HH, aromatic), 2.35 (s, 3H, Ac), 1.88 (bs, 2H5 NH2). HR-MS (ESI) calcd for C26Hi9F3NO2S+ (M+l) 466.1083, found 466.1081.

[5-(4-Acetylphenyl)-2-amino-4-(3-trifluoromethylphenyl)thiophen-3-yl]phenyl methanone (Reference Example 4) Method A. The residue obtained was chromatographed on silica gel eluting with EtOAc :pet ether (5:95) to provide a clear pale yellow resin that was crystallised from MeOH/H2O (90:10). The solid obtained was filtered and washed with H2O to give a pale yellow powder (54 mg, 50%). This cross coupled product (40 mg, 70.72 μmol) was dissolved in CH2Cl2 (1 rnL), TFA (300 μ L) was added and the reaction was stirred at room temperature. After 2 h the mixture was diluted with CHCl3 (10 mL), evaporated and chromatographed on silica gel eluting with CHCl3 providing a yellow powder (19 mg, 58%). Mp 190-196 0C. 1H NMR δ 7.74 (d, J= 8.4 Hz, 2H, aromatic), 7.20-6.91 (m, 1 IH, aromatic), 2.52 (s, 3H, Ac), 1.90 (bs, 2H, NH2). HR-MS (ESI) calcd for C26Hi9F3NO2S+ (M+l) 466.1083, found 466.1081.

[2-amino-5-(4-nitrophenyl)-4-(3-trifluoromethy]phenyl)thiopheπ-3-yl]phenyl methanone (Reference Example 5)

Method A. The residue obtained was dissolved in a minimum of MeOH and crystallised upon the addition of water. The resultant solid was filtered and washed with H2O to provide a yellow powder (75 mg, 69%). This cross coupled product (50 mg, 87.94 μmol) was dissolved in CH2Cl2 (1 mL), TFA (1 mL) was added and the reaction was stirred at room temperature. After 2 h, the mixture was diluted with CHCl3 (10 mL) and concentrated to a solid that was filtered and washed with water (43 mg). The solid was chromatographed on silica gel eluting with EtOAc:pet ether (20:80) to afford a semi-solid that was triturated with 80% MeOH/H2O to give an orange solid (22 mg, 41%). Mp 221- 229 °C. 1H NMR δ = 8.01 (d, J = 8.7 Hz, 2H, aromatic), 7.19-7.17 (m, 3H, aromatic), 7.12-7.04 (m, 6H, aromatic), 6.98-6.93 (m, 2H, aromatic), 2.31 (bs, 2H, NH2). HR-MS (ESI) calcd for C24H16F3N2O3S+ (M+l) 469.0828, found 469.0828.

[2-Amino-5-(4-chlorophenyI)-4-(3-trifluoromethyIphenyl)thiophen-3-yl]phenyl methanone (Reference Example 6)

Method A. The residue obtained was crystallised from MeOH. The solid was filtered and washed with ice-cold MeOH to provide a tan coloured powder (51 mg, 48%). This cross coupled product (46 mg, 82.44 μmol) was dissolved in CH2Cl2 (1 mL), TFA (200 μL) was added and the reaction was stirred at room temperature. After 1.5 h, the mixture was diluted with CHCl3 (10 mL) and evaporated to give a reddish brown residue. The residue was triturated with a minimum amount of ice-cold MeOH and the resultant solid was filtered and washed with MeOH/H2O (60:40) to afford a yellow powder (31 mg, 82%). Mp 185-194 °C. 1H NMR δ 7.20-6.90 (m, 13H5 aromatic), 5.21 (bs, 2H, NH2). MS (APCI): m/z = 60.0 (40%), 458.0 (100%) (M + H)+. HR-MS (ESI) calcd for C24H16ClF3NOS+ (M+l) 458.0588, found 458.0591.

[2-Amino-5-(4-methoxyphenyI)-4-(3-trifluoromethylphenyl)thiophen-3-yl]phenyl methanone (Reference Example 7)

Method B. The residue obtained was sufficiently pure for the next step. It was dissolved in CH2Cl2 (1 rnL), TFA (1 niL) was added and the reaction was stirred at room temperature. After 3 h, the mixture was diluted with CHCl3 (10 mL) and evaporated to give a reddish brown residue. Chromatography on a silica gel column, eluting with 15:85 EtOAc:pet ether (15:85), yielded a light yellow resin. This material was crystallised by sonicating in a minimum of methanol to afford a yellow powder (36 mg, 22%). Mp 68-71 0C. 1H NMR δ 7.21-7.19 (m, 2H, aromatic), 7.09-6.91 (m, 9H5 aromatic), 6.77-6.72 (m, 2H, aromatic), 3.74 (bs, 3H, CH3O) 2.25 (bs, 2H, NH2).

Ethyl 2-Amino-5-phenyl-4-(3-trifluoromethylphenyl)thiophene-3-carboxylate

(Reference Example 8)

Method B. The residue obtained was sufficiently pure for the next step. It was dissolved in CH2Cl2 (1 mL), TFA (1 mL) was added and the reaction was stirred at room temperature.

After 3 h, the mixture was diluted with CHCl3 (10 mL) and evaporated to give a reddish brown residue. This residue was chromatographed on a silica gel column eluting with

EtOAc:pet ether (15:85) to provide a pink resin (141 mg), which solidified upon standing.

Complete crystallisation was induced by sonicating in 50% aqueous methanol to yield a pink powder (76 mg, 48%). Mp 113116 0C. 1H NMR δ 7.53 (bs, 2H, aromatic), 7.38-7.30

(m, 2H, aromatic), 7.20-6.95 (m, 5H, aromatic), 4.00 (bs, 2H, NH2), 3.95 (q, J = 7.2 Hz,

2H, CH2CH3), 0.80 (t, J= 7.2 Hz, 3H, CH2CH3).

Ethyl 5-(3-Acetylphenyl)-2-amino-4-(3-trifluoromethylphenyl)thiophene-3- carboxylate (Reference Example 9)

Method A. The residue obtained was crystallised from MeOH. The solid was filtered and washed with ice-cold MeOH to give an off white powder (75 mg, 69%). This cross coupled product (75 mg, 140.57 μmol) was dissolved in CH2Cl2 (1 mL), TFA (200 μ L) was added and the reaction was stirred at room temperature. After 3 h, the mixture was diluted with CHCl3 (10 mL) and concentrated to a brown/red residue. The residue was chromatographed on a silica gel column eluting with EtOAc:pet ether (15:85), to provide a brown semi-solid (35 mg). The solid was dissolved in a minimum of MeOH and precipitated by the addition of water, yielding an off white powder (33 mg, 54%). Mp 164- 170 °C. 1H NMR δ 7.70 (m, IH, aromatic), 7.56-7.54 (m, 3H, aromatic), 7.41-7.31 (m, 2H, aromatic), 7.26-7.23 (m, 2H, aromatic), 4.12 (bs, 2H, NH2), 3.95 (q, J - 7.2 Hz, 2H, CH2CH3), 2.32 (s, 3H, Ac), 0.79 (t, J = 7.2 Hz, 3H, CH2CH3). ΗR-MS (ESI) calcd for C22H19F3NO3S+ (MHhI) 434.1032, found 434.1031.

Ethyl 5-(4-Acetylphenyl)-2-amino-4-(3-trifluoromethylphenyl)thiophene-3- carboxylate (Reference Example 10) Method A. The residue obtained was crystallised from MeOH. The solid was filtered and washed with ice-cold MeOH to give a peach coloured powder (100 mg, 93%). This cross coupled product (100 mg, 187.42 μmol) was dissolved in CH2Cl2 (1 mL), TFA (400 μ L) was added and the reaction was stirred at room temperature. After 2 h, the mixture was diluted with CHCl3 (10 mL) and concentrated to a black/green residue. The residue was chromatographed on a silica gel column eluting with CHCl3, providing a yellow resin (54 mg) that solidified upon standing. The solid was recrystallised from MeOH to afford a yellow powder (13.5 mg, 16%). Mp 167-170 °C. 1H NMR δ 7.71 (d, J = 8.4 Hz, 2H, aromatic), 7.58-7.53 (m, 2H, aromatic), 7.41-7.30 (m, 2H, aromatic), 7.05 (d, J = 8.4 Hz, 2H, aromatic), 3.93 (q, J= 12 Hz, 2H, CH2CH3), 2.51 (s, 3H, Ac), 0.79 (t, J= 7.2 Hz, 3H, CH2CH3). ΗR-MS (ESI) calcd for C22H19F3NO3S+(MH-I) 434.1032, found 434.1030.

Ethyl 2-Amino-5-(4-nitrophenyl)-4-(3-trifluoromethyIphenyl)thiophene-3-carboxylate (Reference Example 11)

Method A. The residue obtained was crystallised from MeOH. The solid was filtered and washed with ice-cold MeOH to give a brownish yellow powder (75 mg, 69%). This cross coupled product (75 mg, 139.79 μmol) was dissolved in CH2Cl2 (1 mL), TFA (200 μL) was added and the reaction was stirred at room temperature. After 3 h, the mixture was diluted with CHCl3 (10 niL) and concentrated to a reddish brown residue. The residue was chromatographed on a silica gel column eluting with EtOAc:pet ether (15:85), providing a reddish brown resin (82 mg). The resin was crystallised from MeOH / water to afford a reddish brown powder (33 mg, 54%). Mp 178-184 0C. 1H NMR δ 7.97 (d, J= 8.7 Hz5 2H, aromatic), 7.60 (d, J = 7.8 Hz, IH, aromatic), 7.53 (s, IH, aromatic), 7.42 (t, J= 7.7 Hz, IH, aromatic), 7.32 (d, J- 7.5 Hz, IH, aromatic), 7.08 (d, J= 8.7 Hz, 2H, aromatic), 3.95 (q, J = 7.2 Hz, 2H, CH2CH3), 0.79 (t, J = 7.2 Hz, 3H5 CH2CH3). ΗR-MS (ESI) calcd for C20H16F3N2O4S+ (M+l) 437.0777, found 437.0781.

Ethyl 2-Amino-5-(4-chlorophenyl)-4-(3-trifluoromethylphenyl)thiophene-3- carboxylate (Example 2)

Method A. The residue obtained was crystallised from MeOH. The solid was filtered and washed with ice-cold MeOH to give a white powder (102 mg, 96%). This cross coupled product (100 mg, 190.13 μmol) was dissolved in CH2Cl2 (1 mL), TFA (1 mL) was added and the reaction was stirred at room temperature. After 3 h, the mixture was diluted with CHCl3 (10 mL) and concentrated to a reddish brown residue. The residue was chromatographed on a silica gel column eluting with EtOAc:pet ether (10:90) to give a pink resin (70 mg). The resin was recrystallised from EtOH / water to afford a pink powder (57 mg, 70%). Mp 127-129 0C. 1H NMR δ 7.55-7.48 (m, 2H, aromatic), 7.39-7.26 (m, 2H, aromatic), 7.16-6.91 (m, 4H, aromatic), 3.94 (q, J= 7.2 Hz, 2H, CH2CH3), 0.78 (t, J= 7.2 Hz, 3H, CH2CH3). ΗR-MS (ESI) calcd for C20Hi6ClF3NO2S+ (M+l) 426.0537, found 426.0552.

Ethyl 2-Amino-5-(4~methoxyphenyl)-4-(3-trifluoromethylphenyl)thiophene-3- carboxylate (Reference Example 12)

Method B. The residue obtained was sufficiently pure for the next step. It was dissolved in CH2Cl2 (1 mL), TFA (1 mL) was added and the reaction was stirred at room temperature. After 3 h, the mixture was diluted with CHCl3 (10 mL) and concentrated to a reddish brown residue. The residue was chromatographed on a silica gel column eluting with EtOAc:pet ether (15:85), to provide a light purple resin which slowly solidified upon standing. Complete crystallisation was induced by sonication in 50% aqueous methanol, giving a light purple powder (91 mg, 49%). Mp 112-116 °C. 1H NMR δ 7.51-7.49 (m, 2H, aromatic), 7.37-7.27 (m, 2H5 aromatic), 7.10-6.65 (m, 4H, aromatic), 3.94 (q, J = 7.2 Hz, 2H, CH2CH3), 3.73 (bs, 3H, CH3O) 0.79 (t, J= 7.2 Hz, 3H, CH2CH3).

[2-amino-4-(3-trifluoromethylphenyl)-5-(4-trifluoromethyIphenyl)thiophen-3- yl] phenyl methanone (Reference Example 13)

Method A. The residue obtained was crystallised from MeOH. The solid was filtered and washed with ice-cold MeOH to give a light brown powder (100 mg, 88%). This cross coupled product (100 mg, 178.73 μmol) was dissolved in CH2Cl2 (1 mL), TFA (400 μL) was added and the reaction was stirred at room temperature. After 2 h, the mixture was diluted with CHCl3 (10 mL) and concentrated to a reddish brown residue. The residue was chromatographed on a silica gel column eluting with CHCl3, providing a brown solid (55 mg). The solid was triturated with a minimum of ice-cold 80% MeOH/H2O to yield a brown powder (35 mg, 43%). Mp 135-140 °C. 1H NMR δ 7.57-7.53 (m, 2H, aromatic), 7.41-7.36 (m, 3H, aromatic), 7.32-7.29 (m, IH, aromatic), 7.08 (d, J = 8.1 Hz, 2H, aromatic), 3.94 (q, J= 7.2 Hz, 2H, CH2CH3), 2.04 (bs, 2H, NH2), 0.79 (t, J= 7.2 Hz, 3H, CH2CH3). ΗR-MS (ESI) calcd for C21Hi6F6NO2S+ (M+l) 460.0800, found 460.0800.

Ethyl 2-Amino-5-(4-pyridyl)-4-(3-trifluoromethylphenyl)thiophene-3-carboxylate (Reference Example 14)

Method A. The residue obtained was chromatographed on silica gel eluting with EtOAc:pet ether (15:85) to give a clear colourless resin (32 mg). The resin was crystallised by dissolving MeOH and precipitating with water. The solid was washed with water to provide a white powder (26 mg, 26%). This cross coupled product (25 mg, 50.76 μmol) was dissolved in EtOH (1 mL), 6M HCl (200 μL) was added and the reaction was stirred at room temperature. After 2 h, the mixture was heated on an oil bath at 50-60 °C for 24 h. The solution was concentrated to a green/yellow solid. The solid was recrystallised from EtOH/ether to afford a green solid as the hydrochloride salt (21 mg, 96%). Mp 164-170 0C. 1H NMR (DMSO): δ 8.44 (d, J= 6.0 Hz, 2H, aromatic), 8.36 (bs, 2H, NH2), 7.84 (d, J= 7.5 Hz, IH, aromatic), 7.71-7.66 (m, 2H, aromatic), 7.56 (d, J= 7.5 Hz, IH, aromatic), 7.11 (d, J= 6.3 Hz, 2H, aromatic), 3.86 (m, 2H, CH2CH3), 0.72 (t, J = 7.2 Hz, 3H, CH2CH3). ΗR-MS (ESI) calcd for Ci9Hi6F3N2O2S+ (M+l) 393.0879, found 393.0868.

[2-Amino-5-chIoro-4-(3-(trifluoromethyl)phenyl)thiophen-3-yl]phenyl methanone (Reference Example 15)

Example 1 (0.65 mg, 1.86 mmol) and phthalic anhydride (0.33 g, 2.23 mmol) were dissolved in 17 mL of glacial acetic and refluxed overnight. The solution was concentrated and the resultant solid was recrystallised from 5rec-butanol/H2O (80:20) to give compound phthaloyl protected product as a pale yellow solid (661 mg). This crude product (200 mg, 0.42 mmol) was dissolved in 50:50 CHCl3:AcOH (4 mL) and NCS (67 mg, 0.50 mmol) was added. After 10 min, DMF (0.5 mL) was also added to solubilise all solids. The homogeneous solution was stirred at room temperature for 3 h. An additional portion NCS (67 mg, 0.50 mmol) was added and the reaction mixture was stirred overnight. The solution was diluted with water and extracted with EtOAc. The organic phase was washed with dilute sodium bicarbonate solution then water. The organic layer was dried (MgSO4), filtered and concentrated to a yellow resin. The resin was filtered through a silica gel plug eluting with diethyl ether to give a pale yellow foam that was crystallised from MeOH (142 mg, 66%). The resultant solid (140 mg, 0.27 mmol) was dissolved in 2 mL of dioxane / EtOH (1 :1) and vigorously stirred at room temperature. Hydrazine hydrate (18.6 μL, 0.38 mmol) was added and stirring was continued for 2.5 h. The mixture was concentrated and chromatographed on silica gel eluting with CHCl3, to afford a yellow resin (60 mg). This material was dissolved in a minimum of MeOH and precipitated with water (21 mg, 20%). Mp 139-141 0C. 1H NMR δ 7.24-7.06 (m, 9H, aromatic and NH2), 6.99-6.93 (m, 2H, aromatic). HR-MS (ESI) calcd for Ci8H12ClF3NOS+ (M+l) 382.0275, found 382.0276.

[2-Amino-5-bromo-4-(3-(trifluoromethyl)phenyl)thiophen-3-yl]phenyI methanone (Reference Example 16)

The phthaloyl protected product as described above in Reference Example 15 (60 mg, 0.13 mmol) was dissolved in 50:50 CH2Cl2:Ac0H (1 mL) and cooled to 0 0C with ice bath. NBS (27 mg, 0.15 mmol) was added and the reaction mixture was stirred at room temperature for 1.5 h. The solution was concentrated to a residue and then taken up in EtOAc. The EtOAc solution was washed with 5% sodium bicarbonate solution (x 2), water and brine. The organic layer was dried (MgSO4), filtered and concentrated to give a pale yellow solid (65 mg, 93%). HR-MS (ESI) calcd for C26Hi4BrF3NO3S+ (M+l) 555.9824, found 555.9824. The crude product (50 mg, 0.09 mmol) was dissolved in 0.5 mL of EtOH and vigorously stirred at room temperature. Hydrazine hydrate (6.0 μL, 0.124 mmol) was added slowly and dropwise. After stirring at room temperature for 20 min, dioxane (0.5 mL) was added to solubilise all materials and was left to stir overnight. The next day a further 5 μL of hydrazine hydrate was added and after 1 min a precipitate formed. The solution was immediately concentrated and the residue obtained was filtered through a silica gel plug eluting with 50:50 EtOAc :pet ether to provide a pale yellow resin that solidifies upon standing at 4 0C. Complete crystallisation was induced by dissolving in a minimum of MeOH and adding water to afford a green solid (37 mg, 96%). Mp 122-124 °C. 1H NMR δ 7.25-7.06 (m, 7H, aromatic), 6.98-6.93 (m, 2H, aromatic), 6.35 (bs, 2H, NH2). MS (APCI): m/z = 426.0 (90%), 428.0 (100%) (M + H)+. HR-MS (ESI) calcd for Ci8Hi2BrF3NOS+ (M+l) 425.9770, found 425.9770.

2. Pharmacology Experimental Binding Kinetic assay of AE Activity. The binding kinetic assay of AE activity consisted of three phases: (1) binding to equilibrium of the agonist, 125I-ABA to the AiAR-G protein ternary complex; (2) stabilization of that complex by adding vehicle or AE for 30 min, and (3) dissociation of the complex by adding a combination of an A1AR antagonist, 100 μM BW-1433, and 25 μM GTPγS for 10 min. Compounds were scored between 0% (no different than AE vehicle) and 100% (complete abolition of 125I-ABA dissociation). The assay employed membranes from CHO-Kl cells stably expressing the ILA1AR. For agonist binding to equilibrium (phase 1) the buffer consisted of 10 mM HEPES, pH 7.2, containing 0.5 mM MgCl2, 1 LVmL adenosine deaminase, 0.5 nM 125I-ABA and 10 μg of membrane protein in a final volume of 100 μL applied to 96 well Millipore GF/C glass fiber filter plates. After 90 minutes at room temperature the addition of 50 μL of AE (0.1 - 50 μM, final) initiated stabilization of the ternary complex (phase 2). Thirty minutes later 50 μL solution containing BW- 1433 and GTPγS was added to initiate the dissociation of the ternary complex. Ten minutes later membranes were filtered, washed, dried and counted for residual 125I-ABA. The percentage of specifically bound agonist remaining after 10 minutes of dissociation served as an index of AE activity:

% AE score = 100 x (B-B0) / (Beq-B0)

Where B = residual binding (cpm) bound at the end of 10 minutes of dissociation in the presence of an AE, B0 = residual binding (cpm) at the end of 10 minutes of dissociation in the absence of an AE and Beq = cpm bound at the end of 90 minutes of equilibrium binding.

The percentage of specific binding remaining after 10 minutes of dissociation constitutes an index of AE activity for ranking candidate compounds. A score of 100 % means no dissociation and a score of zero means complete dissociation.

Assay of AiR Antagonist Activity.

CHOKl membranes expressing human Ai adenosine receptors were resuspended at 400μg/mL in HE buffer containing lU/mL adenosine deaminase. 50 μL of membrane solution was added to 50 μL HE buffer containing [3H] CPX (2 nM). 100 μL of HE buffer with either vehicle, enhancer or NECA (to define non-specific) was added. The final drug concentrations were 10 μM for enhancer and 100 μM for NECA. Samples were incubated for 90 minutes at room temperature, filtered and counted on a liquid scintillation counter. Binding was performed in triplicate and expressed as % inhibition as compared to control binding.

[35S]-GTPyS Binding Assay

Membrane Preparation - When CHO-FIpIn cells, stably expressing the human adenosine

A] receptor, were approximately 90% confluent, they were harvested using trypsinization and centrifuged (300 g, 3 minutes). The pellet was then resuspended in HEPES homogenization buffer (5OmM HEPES, 2.5mM MgCl2, 2mM EGTA) and the centrifugation procedure repeated. The intact cell pellet was resuspended in HEPES homogenization buffer and homogenized using a Polytron homogenizer for two 10-second intervals at maximum setting, with 30 second cooling periods on ice between each burst. The homogenate was centrifuged (1000 g, 10 min, 25°), the pellet discarded and the supernatant recentrifuged (30,000 g, 30 min, 40C). The resulting pellet was resuspended in 5mL assay buffer (1OmM HEPES, 10OmM NaCl, 1OmM MgCl2; pH 7.4 at 30°C) and the protein content determined using the method of Bradford (1976).

Membrane homogenates (15μg) were equilibrated in a 500μL total volume of assay buffer containing 1 OμM guanosine 5 '-diphosphate (GDP) and a range of concentrations of R-PIA (O.OlnM - lOμM) in the absence or presence of VCP171 (0.1 μM to 3μM) at 30°C for 60 minutes. After this time, 50μL of [35S]-GTPyS (InM) was added and incubation continued for 30 minutes at 3O0C. Incubation was terminated by rapid filtration through Whatman GF/B filters using a Brandell cell harvester (Gaithersburg, MD). Filters were washed three times with 3 mL aliquots of ice-cold 0.9% NaCl buffer and dried before the addition of 4 mL of scintillation cocktail (Ultima Gold; Packard Bioscience, Meriden, CT). Vials were then left to stand until the filters became uniformly translucent before radioactivity was determined in DPM using scintillation counting.

AiAR-Mediated ERK 1/2 Phosphorylation Assays

CHO-FIpIn cells stably expressing the human adenosine A1 receptor were seeded into 96- well plates at a density of 50 000 cells/well. After 4 hours, cells were washed twice with PBS and maintained in DMEM containing 16mM HEPES and 50U/mL penicillin- streptomycin for at least 4 hours before assaying. Assays investigating the time course of action of ERK 1/2 phosphorylation were generated by the addition of ligand for various time periods (200μL final volume) at 370C. The agonist R-PIA peaked at 5min while Example 1 peaked at 1 Omin. The time of stimulation when constructing concentration- response curves was chosen from the time to peak response as determined in the time course assays, lOmin for the allosteric stimulation and 5min for the agonist stimulation. Stimulation of cells was terminated by the removal of media and the addition of lOOμL of SureFire™ lysis buffer to each well. The plate was then agitated for 1-2 minutes. A 4:1 v/v dilution of Lysate:SureFire™ activation buffer was made in a total volume of 50μL. A 1:100:120 v/v dilution of AlphaScreen™ beads activated lysate mixtwQ-.SureFire™ reaction buffer in a l lμL total volume was then transferred to a white opaque 384-well Proxiplate™ in diminished light. This plate was then incubated in the dark at 37°C for 1.5 hours after which time the fluorescence signal was measured by a Fusion-α™ plate reader (PerkinElmer), using standard AlphaScreen™ settings. Full concentration-response curves of R-PIA in presence of increasing concentration of Example 1 were expressed as a percentage of the ERK 1/2 phosphorylation mediated after a 6 minutes exposure to DMEM containing 3% FBS, and screening interaction studies with a single concentration of R-PIA and two concentrations of VCP ligands were expressed as a percentage of maximal effect of R-PIA.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

CLAIMS:

1. A compound of formula (I) or a salt thereof;

wherein: n and m are independently an integer from 0 to 3; and each Ri and R2 independently represents carboxyl, cyano, dihalomethoxy, halogen, hydroxy, nitro, pentahaloethyl, phosphono, phosphorylamino, phosphinyl, thio, sulfinyl, sulfonyl, trihaloethenyl, trihalomethanethio, trihalomethoxy, trihalomethyl, optionally substituted acyl, optionally substituted acylamino, optionally substituted acylimino, optionally substituted acyliminoxy, optionally substituted acyloxy, optionally substituted arylalkyl, optionally substituted arylalkoxy, optionally substituted alkenyl, optionally substituted alkenyloxy, optionally substituted alkoxy, optionally substituted alkyl, optionally substituted alkynyl, optionally substituted alkynyloxy, optionally substituted amino, optionally substituted aminoacyl, optionally substituted aminoacyloxy, optionally substituted aminosulfonyl, optionally substituted aminothioacyl, optionally substituted aryl, optionally substituted arylamino, optionally substituted aryloxy, optionally substituted cycloalkenyl, optionally substituted cycloalkyl, optionally substituted heteroaryl, optionally substituted heterocyclyl, optionally substituted oxyacyl, optionally substituted oxyacylamino, optionally substituted oxyacylimino, optionally substituted oxyacyloxy, optionally substituted oxysulfmylamino, optionally substituted oxysulfonylamino, optionally substituted oxythioacyl, optionally substituted oxythioacyloxy, optionally substituted sulfinyl, optionally substituted sulfmylamino, optionally substituted sulfonyl, optionally substituted sulphonylamino, optionally substituted thio, optionally substituted thioacyl, optionally substituted thioacylamino, or optionally substituted thioacyloxy.

2. A compound of formula (II) or a salt thereof;

wherein: n is an integer from 0 to 3; Ri independently represents carboxyl, cyano, dihalomethoxy, halogen, hydroxy, nitro, pentahaloethyl, phosphono, phosphorylamino, phosphinyl, thio, sulfmyl, sulfonyl, trihaloethenyl, trihalomethanethio, trihalomethoxy, trihalomethyl, optionally substituted acyl, optionally substituted acylamino, optionally substituted acylimino, optionally substituted acyliminoxy, optionally substituted acyloxy, optionally substituted arylalkyl, optionally substituted arylalkoxy, optionally substituted alkenyl, optionally substituted alkenyloxy, optionally substituted alkoxy, optionally substituted alkyl, optionally substituted alkynyl, optionally substituted alkynyloxy, optionally substituted amino, optionally substituted aminoacyl, optionally substituted aminoacyloxy, optionally substituted aminosulfonyl, optionally substituted aminothioacyl, optionally substituted aryl, optionally substituted arylamino, optionally substituted aryloxy, optionally substituted cycloalkenyl, optionally substituted cycloalkyl, optionally substituted heteroaryl, optionally substituted heterocyclyl, optionally substituted oxyacyl, optionally substituted oxyacylamino, optionally substituted oxyacylimino, optionally substituted oxyacyloxy, optionally substituted oxysulfinylamino, optionally substituted oxysulfonylamino, optionally substituted oxythioacyl, optionally substituted oxythioacyloxy, optionally substituted sulfinyl, optionally substituted sulfϊnylamino, optionally substituted sulfonyl, optionally substituted sulphonylamino, optionally substituted thio, optionally substituted thioacyl, optionally substituted thioacylamino, or optionally substituted thioacyloxy; R3 represents halogen; and R4 represents C1-3 alkyl.

3. A method of preparing a compound of formula (III) or a salt thereof:

said method comprising the steps of:

a) coupling a compound of formula (Ilia) with a substituted acetonitrile of formula (HIb)

(HIa) (HIb)

to form a compound of formula (HIc)

b) cyclising the compound of formula (IIIc) in the presence of elemental sulphur to form a thiophene of formula (HId) and optionally protecting the 2-amino group on the compound of formula (HId);

c) halogenating the 5 -position of the compound of formula (HId) to form a compound of formula (HIe)

d) coupling the compound of formula (HIe) with a compound of formula (LUf) in the presence of a palladium coupling agent R7-Z (IHf) and optionally deprotecting the 2-amino group to form a compound of formula (III);

wherein: n is an integer from 0 to 3; each R1 independently represents carboxyl, cyano, dihalomethoxy, halogen, hydroxy, nitro, pentahaloethyl, phosphono, phosphorylamino, phosphinyl, thio, sulfinyl, sulfonyl, trihaloethenyl, trihalomethanethio, trihalomethoxy, trihalomethyl, optionally substituted acyl, optionally substituted acylamino, optionally substituted acylimino, optionally substituted acyliminoxy, optionally substituted acyloxy, optionally substituted arylalkyl, optionally substituted arylalkoxy, optionally substituted alkenyl, optionally substituted alkenyloxy, optionally substituted alkoxy, optionally substituted alkyl, optionally substituted alkynyl, optionally substituted alkynyloxy, optionally substituted amino, optionally substituted aminoacyl, optionally substituted aminoacyloxy, optionally substituted aminosulfonyl, optionally substituted aminothioacyl, optionally substituted aryl, optionally substituted arylamino, optionally substituted aryloxy, optionally substituted cycloalkenyl, optionally substituted cycloalkyl, optionally substituted heteroaryl, optionally substituted heterocyclyl, optionally substituted oxyacyl, optionally substituted oxyacylamino, optionally substituted oxyacylimino, optionally substituted oxyacyloxy, optionally substituted oxysulfϊnylamino, optionally substituted oxysulfonylamino, optionally substituted oxythioacyl, optionally substituted oxythioacyloxy, optionally substituted sulfinyl, optionally substituted sulfinylamino, optionally substituted sulfonyl, optionally substituted sulphonylamino, optionally substituted thio, optionally substituted thioacyl, optionally substituted thioacylamino, or optionally substituted thioacyloxy; R5 IS (1) -Ph-(R.2)m where m is an integer from 0 to 3 and each R2 independently represents carboxyl, cyano, dihalomethoxy, halogen, hydroxy, nitro, pentahaloethyl, phosphono, phosphorylamino, phosphinyl, thio, sulfinyl, sulfonyl, trihaloethenyl, trihalomethanethio, trihalomethoxy, trihalomethyl, optionally substituted acyl, optionally substituted acylamino, optionally substituted acylimino, optionally substituted acyliminoxy, optionally substituted acyloxy, optionally substituted arylalkyl, optionally substituted arylalkoxy, optionally substituted alkenyl, optionally substituted alkenyloxy, optionally substituted alkoxy, optionally substituted alkyl, optionally substituted alkynyl, optionally substituted alkynyloxy, optionally substituted amino, optionally substituted aminoacyl, optionally substituted aminoacyloxy, optionally substituted aminosulfonyl, optionally substituted aminothioacyl, optionally substituted aryl, optionally substituted arylamino, optionally substituted aryloxy, optionally substituted cycloalkenyl, optionally substituted cycloalkyl, optionally substituted heteroaryl, optionally substituted heterocyclyl, optionally substituted oxyacyl, optionally substituted oxyacylamino, optionally substituted oxyacylimino, optionally substituted oxyacyloxy, optionally substituted oxysulfinylamino, optionally substituted oxysulfonylamino, optionally substituted oxythioacyl, optionally substituted oxythioacyloxy, optionally substituted sulfinyl, optionally substituted sulfinylamino, optionally substituted sulfonyl, optionally substituted sulphonylamino, optionally substituted thio, optionally substituted thioacyl, optionally substituted thioacylamino, or optionally substituted thioacyloxy; or (2) -OR4' where R4' represents optionally substituted C1-3 alkyl, optionally substituted aryl;

R7 is optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkenyl, optionally substituted alkyl, optionally substituted alkynyl; Hal is chloro, bromo or iodo; and

Z is halogen, triflate, sulfonate, BrZn, Sn(alkyl)3, Sn(aryl)3 or B(OR8)2 where R8 is H or alkyl.

4. A compound of formula (I) or a salt thereof according to claim 1 wherein m is 0 or 1 and n is 1 or 2.

5. A compound of formula (I) or a salt thereof according to claim 1 wherein m is 0 and n is 1.

6. A compound of formula (I) or a salt thereof according to claim 4 or claim 5 wherein Ri in each instance, is an electron withdrawing group.

7. A compound of formula (I) or a salt thereof according to claim 6 wherein Ri is selected from halogen, nitro, trihaloethenyl, trihalomethanethio, trihalomethoxy and trihalomethyl.

8. A compound of formula (I) or a salt thereof according to claim 1 wherein m is 0, n is 1, and Ri is 3-CF3.

9. A compound of formula (F) or salt thereof:

(I1) wherein

Ria and Rib are each independently selected from hydrogen, halo, and trifluoromethyl, provided that not both R1 a and Rib are hydrogen; and R2a is selected from hydrogen or halo.

10. A compound of formula (V) according to claim 9 wherein, Ri a is Cl, F, or CF3, R1I, is hydrogen and R2a is hydrogen or chloro.

11. A compound of formula (V) according to claim 9 wherein, Rj3 and Rib are both CF3.

12. A compound of formula (F) according to claim 9 wherein, Ri3 is CF3, Cl, or F, Rib is hydrogen and R2a is hydrogen.

13. A compound of formula (I1) according to claim 9 wherein, Ria is CF3, Cl, or F, Rib is hydrogen and R2a is chloro.

14. A compound of formula (II) or a salt thereof according to claim 2 wherein n is 1.

15. A compound of formula (II) or a salt thereof according to claim 14 wherein Ri is an electron withdrawing group.

16. A compound of formula (II) or a salt thereof according to claim 15 wherein Ri is selected from halogen, nitro, trihaloethenyl, trihalomethanethio, trihalomethoxy and trihalomethyl.

17. A compound of formula (II) or a salt thereof according to any one of claims 14 to 16 wherein R3 is chloro.

18. A compound of formula (II) or a salt thereof according to any one of claims 14 to 17 wherein R4 is ethyl or methyl.

19. A compound of formula (II) or a salt thereof according to claim 2 wherein n is 1, Ri is 3-CF3, R3 is 4-Cl and R4 is ethyl.

20. A compound selected from:

(2-amino-4-(3-(trifluoromethyl)phenyl)thiophen-3-yl)(phenyl)methanone; (2-amino-4-phenylthiophen-3-yl)(4-chlorophenyl)methanone; (2-amino-4-(3-chlorophenyl)thiophen-3-yl)(4-chlorophenyl)methanone; (2-amino-4-(4-chlorophenyl)thiophen-3-yl)(4-chlorophenyl)methanone;

(2-amino-4-(4-bromophenyl)thiophen-3-yl)(4-chlorophenyl)methanone;

(2-amino-4-(3-bromophenyl)thiophen-3-yl)(4-chlorophenyl)methanone;

(2-amino-4-(2-fluorophenyl)thiophen-3-yl)(4-chlorophenyl)methanone;

(2-amino-4-(3-fluorophenyl)thiophen-3-yl)(4-chlorophenyl)methanone; (2-amino-4-(4-fluorophenyl)thiophen-3 -yl)(4-chlorophenyl)methanone;

(2-amino-4-(3-nitrophenyl)thiophen-3-yl)(4-chlorophenyl)methanone;

(2-amino-4-(3-nitrophenyl)thiophen-3-yl)(4-chlorophenyl)methanone;

(2-amino-4-(3-methoxyphenyl)thiophen-3-yl)(4-chlorophenyl)methanone;

(2-amino-4-(4-methoxyphenyl)thiophen-3-yl)(4-chlorophenyl)methanone; (2-amino-4-(4-iodophenyl)thiophen-3-yl)(4-chlorophenyl)methanone;

(2-amino-4-(3-(trifluoromethyl)phenyl)thiophen-3-yl)(4-chlorophenyl)methanone;

(2-amino-4-(3,5-bis(trifluoromethyl)phenyl)thiophen-3-yl)(4-chlorophenyl)methanone;

(2-amino-4-phenylthiophen-3-yl)(phenyl)methanone;

(2-amino-4-(2-fluorophenyl)thiophen-3-yl)(phenyl)methanone; (2-amino-4-(3-fluorophenyl)thiophen-3-yl)(phenyl)methanone;

(2-amino-4-(4-fluorophenyl)thiophen-3-yl)(phenyl)methanone;

(2-amino-4-(4-bromophenyl)thiophen-3-yl)(phenyl)methanone;

(2-amino-4-(3 -bromophenyl)thiophen-3 -yl)(phenyl)methanone;

(2-amino-4-(3-chlorophenyl)thiophen-3-yl)(phenyl)methanone; (2-amino-4-(4-chlorophenyl)thiophen-3 -yl)(phenyl)methanone;

(2-amino-4-(4-iodophenyl)thiophen-3-yl)(phenyl)methanone; (2-amino-4-(4-methoxyphenyl)thiophen-3-yl)(phenyl)methanone; (2-amino-4-(3-methoxyphenyl)thiophen-3-yl)(phenyl)methanone; (2-amino-4-(3 -nitrophenyl)thiophen-3 -yl)(phenyl)methanone; (2-amino-4-(4-nitrophenyl)thiophen-3 -yl)(phenyl)methanone; and (2-amino-4-(3,5-bis(trifluoromethyl)phenyl)thiophen-3-yl)(phenyl)niethanone.

21. A compound selected from :

(2-amino-4-(3-(trifluoromethyl)phenyl)thiophen-3-yl)(phenyl)methanone; (2-amino-4-(3-chlorophenyl)thiophen-3-yl)(4-chlorophenyl)methanone; (2-amino-4-(2-fluorophenyl)thiophen-3-yl)(4-chlorophenyl)methanone;

(2-amino-4-(3-fluorophenyl)thiophen-3-yl)(4-chlorophenyl)methanone;

(2-amino-4-(3-(trifluoromethyl)phenyl)thiophen-3-yl)(4-chlorophenyl)methanone;

(2-amino-4-(3,5-bis(trifluoromethyl)phenyl)thiophen-3-yl)(4-chlorophenyl)methanone; and (2-amino-4-(3,5-bis(trifluoromethyl)phenyl)thiophen-3-yl)(phenyl)methanone.

22. A method of treating or managing pain or providing cardioprotection comprising the administration of an effective amount of a compound of formula (I) or (II) according to any one of claims 1 to 21 to a subject in need thereof.

23. Use of a compound of formula (I) or (II) or a salt thereof according to any one of claims 1 to 21 in the manufacture of a medicament for treating or managing pain or providing cardioprotection.

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