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Title:
ACYL BICYCLIX DERIVATIVES OF PYRROL
Document Type and Number:
WIPO Patent Application WO/2003/097646
Kind Code:
A1
Abstract:
The invention relates to anti-viral agents of Formula (I); wherein: RA represents OR1, NR1R2, or R1 wherein R1 and R2 independently represent hydrogen, C1-6alkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl; or R1 and R2 together with the nitrogen atom to which they are attached form a 5 or 6 membered saturated cyclic group; RB represents C(O)R3 wherein R3 represents aryl or heteroaryl; RC represents C1-6alkyl, aryl, heteroaryl or heterocyclyl; RD represents hydrogen and RE represents hydrogen, OR4 or SR4, or RD and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; when RE is hydrogen, OR4 or SR4, RG and RH are both hydrogen; when RD and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, RG represents hydrogen and RH represents hydrogen, OR4 or SR4, or RG and RH together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; R4 represents hydrogen, C1-6alkyl or aryl; when RD and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, and RG and RH are both hydrogen or RG and RH together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, then RF represents O, S, NR5 or CR6R7, otherwise RF represents CR6R7; R5 represents hydrogen, C1-6alkyl, arylalkyl or aryl;R6 and R7 independently represent hydrogen, C1-6alkyl, arylalkyl or heteroarylalkyl;RJ represents hydrogen, C1-6alkyl, heterocyclylalkyl, arylalkyl or heteroarylalkyl; and salts, solvates and enantiomers thereof;provided that when RA is OR1 then R1 is other than tert-butyl, for use in medical therapy. A process for the preparation of compounds of Formula (I) and methods of using them in HCV treatment are provided.

Inventors:
SLATER MARTIN JOHN (GB)
HOWES PETER DAVID (GB)
Application Number:
PCT/GB2003/002105
Publication Date:
November 27, 2003
Filing Date:
May 15, 2003
Export Citation:
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Assignee:
GLAXO GROUP LTD (GB)
SLATER MARTIN JOHN (GB)
HOWES PETER DAVID (GB)
International Classes:
A61K31/407; A61K31/427; A61P31/12; A61P31/14; C07D417/04; C07D487/04; C07D491/04; C07D491/048; (IPC1-7): C07D487/04; A61K31/407; A61P31/12; C07D417/04; C07D491/04
Domestic Patent References:
WO2001085720A12001-11-15
WO2003037895A12003-05-08
Foreign References:
Other References:
BICKNELL A J ET AL: "Synthesis of a highly functionalized rigid template by solid phase azomethine ylide cycloaddition", BIOORGANIC & MEDICINAL CHEMISTRY LETTERS, OXFORD, GB, vol. 6, no. 20, 22 October 1996 (1996-10-22), pages 2441 - 2444, XP004135854, ISSN: 0960-894X
GRIGG R ET AL: "N-Prop-2-ynylmaleimide. Application to Sequential One-pot Rh(I) Catalysed [2+2+2]-Alkyne Cyclotrimerisation-Imine Cycloaddition", TETRAHEDRON, ELSEVIER SCIENCE PUBLISHERS, AMSTERDAM, NL, vol. 56, no. 45, 3 November 2000 (2000-11-03), pages 8967 - 8976, XP004238552, ISSN: 0040-4020
Attorney, Agent or Firm:
Crawley, Karen (980 Great West Road Brentford, Middlesex TW8 9GS, GB)
Download PDF:
Claims:
Claims
1. A compound of Formula (I) wherein: RA represents OR1, NR1R2, or R'wherein R'and R independently represent hydrogen, C16alkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl ; or R'and R2 together with the nitrogen atom to which they are attached form a 5 or 6 membered saturated cyclic group; RB represents C (O) R3 wherein R3 represents aryl or heteroaryl ; RC represents C16alkyl, aryl, heteroaryl or heterocyclyl ; R° represents hydrogen and RE represents hydrogen, OR4 or SR4, or R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; when RE is hydrogen, OR4 or SR4, R and R"are both hydrogen; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, R represents hydrogen and R"represents hydrogen, OR4 or SR4, or RG and R"together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; R4 represents hydrogen, C16alkyl or aryl ; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, and RG and R"are both hydrogen or RG and R" together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, then RF represents O, S, NR5 or CR6R7, otherwise RF represents CR6R7 ; R5 represents hydrogen, C16alkyl, arylalkyl or aryl ; R6 and R7 independently represent hydrogen, C16alkyl, arylalkyl or heteroarylalkyl ; R''represents hydrogen, C, _6alkyl, heterocyclylalkyl, arylalkyl or heteroarylalkyl ; and salts, solvates and enantiomers thereof; provided that when RA is OR'then R'is other than tertbutyl, for use in medical therapy.
2. Compounds of Formula (I), represented by Formula (A) wherein: RA represents OR', NR1R2, or R'wherein R'and R independently represent hydrogen, C16alkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl ; or R'and R2 together with the nitrogen atom to which they are attached form a 5 or 6 membered saturated cyclic group; RB represents C (O) R3 wherein R3 represents aryl or heteroaryl ; RC represents C, 6alkyl, aryl, heteroaryl or heterocyclyl ; R° represents hydrogen and RE represents hydrogen, OR4 or SR4, or RD and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; when RE is hydrogen, OR4 or SR4, RG and RH are both hydrogen; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, R represents hydrogen and R"represents hydrogen, OR4 or SR4, or RG and R"together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; R4 represents hydrogen, C » alkyl or aryl ; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, and RG and R"are both hydrogen or RG and R" together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, then RF represents O, S, NR5 or CR6R, otherwise R represents CR6R7 ; R5 represents hydrogen, C16alkyl, arylalkyl or aryl ; R6 and R 7independently represent hydrogen, C16alkyl, arylalkyl or heteroarylalkyl ; R''represents hydrogen, C16alkyl, heterocyclylalkyl, arylalkyl or heteroarylalkyl ; and salts, solvates and enantiomers thereof; provided that i) when RA is OR'then R'is other than tertbutyl, and ii) a compound of Formula (A) is other than rel(3aS,6aR)1((1Himidazol5yl)methyl)2(cyclopropylbenzoyl)3(4methoxyphenyl) 5methyloctahydro4, 6dioxopyrrolo [3,4c] pyrrole1carboxylic acid; or rel (1S, 3R, 3aS, 6aR)1methyl2benzoyl3 (4methoxyphenyl)5phenyloctahydro4, 6 dioxopyrrolo [3,4c] pyrrole1carboxylic acid; or rel(1S, 3R, 3aS, 6aR)1methyl2benzoyl3(4nitrophenyl)5methyloctahydro4, 6 dioxopyrrolo [3,4c] pyrrole1carboxylic acid; or rel(1S, 3R, 3aS, 6aR)1benzyl2(phenylethanoyl)3(4methoxyphenyl)5methyl octahydro4, 6dioxopyrrolo [3,4c] pyrrole1carboxylic acid; or rel(1S, 3R, 3aS, 6aR)1(2methylpropyl)2ethanoyl3(4methoxyphenyl)5methyl octahydro4, 6dioxopyrrolo [3, 4c]pyrrole1carboxylic acid; or rel (1S, 3R, 3aS, 6aR)1methyl2ethanoyl3(4methoxyphenyl)5methyloctahydro4, 6 dioxopyrrolo [3,4c] pyrrole1carboxylic acid.
3. A compound as claimed in claim 1 or claim 2 wherein RA is OR1,.
4. A compound as claimed in any of claims 13 wherein RA is OH.
5. A compound as claimed in any of claims 14 wherein R3 is phenyl, optionally substituted by halo, C, _alkyl or C13alkoxy,.
6. A compound as claimed in any of claims claim 15 wherein R3 is 4tertbutylphenyl optionally 3substituted by halo, C, _3alkyl or C13alkoxy.
7. A compound as claimed in any of claims 16 wherein R3 is 4tertbutylphenyl, 3 bromo4tertbutylphenyl or 4tertbutyl3methoxyphenyl,.
8. A compound as claimed in any of claims 17 wherein Rc is heteroaryl.
9. A compound as claimed in any of claims 18 wherein Rc is 1, 3thiaol2yl or pyridin 2yl.
10. A compound as claimed in claim 1 selected from the group consisting of: rel (1 S, 3R, 3aS, 6aR)1Isobutyl2 (4tertbutylbenzoyl)3 (1, 3thiazol2yl)5propyl octahydro4, 6dioxopyrrolo [3,4c] pyrrole1carboxylic acid; rel (1S, 3R, 3aS, 6aR)1isobutyl2 (4tertbutylbenzoyl)3 (1, 3thiazol2yl)5benzyl octahydro4, 6dioxopyrrolo [3,4c] pyrrole1carboxylic acid; rel (1 S, 3R, 3aS, 6aR)1Isobutyl2(4teffbutylbenzoyl)3(1, 3thiazol2yl)5methyl octahydro4, 6dioxopyrrolo [3,4c] pyrrole1carboxylic acid; rel(1 S, 3R, 3aS, 6aR)1Isobutyl2(4teffbutylbenzoyl)3(1, 3thiazol2yl)octahydro4 oxocyclopenta [c] pyrrole1carboxylic acid; rel(3aR, 4S, 6R,6aS)4Isobutyl5(4tertbutylbenzoyl)6(1,3thiazol2yl)hexahydro furo [3,4c] pyrrol1oxo4carboxylic acid; rel (1 S, 3R, 3aS, 6aR)1Isobutyl2(3methoxy4tertbutylbenzoyl)3(1,3thiazol2yl) octahydro4oxocyclopenta [c] pyrrole1carboxylic acid ; rel (1 S, 3R, 3aS, 6aR)1Isobutyl2(3bromo4tertbutylbenzoyl)3(1,3thiazol2yl)5 propyloctahydro4, 6dioxopyrrolo [3,4c] pyrrole1carboxylic acid ; rel (1 S, 3R, 3aS, 6aR)1Isobutyl2 (3bromo4tertbutylbenzoyl)3 (1, 3pyridin2yl)5 propyloctahydro4, 6dioxopyrrolo [3,4c] pyrrole1carboxylic acid ; rel (1 S, 3R, 3aS, 6aR)1Isobutyl2 (4tertbutylbenzoyl)3 (pyridin2yl)5propyl octahydro4, 6dioxopyrrolo [3,4c] pyrrole1carboxylic acid; rel (1 S, 3R, 3aS, 6aR)1Isobutyl2(3methoxy4tertbutylbenzoyl)3(1,3thiazol2yl) octahydro4oxo5, 5dimethylcyclopenta [c] pyrrole1carboxylic acid ; rel(1 S, 3R, 3aS, 6aR)1Isobutyl2(3methoxy4tertbutylbenzoyl)3(5methyl1, 3 thiazol2yl)octahydro4oxocyclopenta [c] pyrrole1carboxylic acid ; and salts, solvates and enantiomers thereof.
11. A method for the treatment of a human or animal subject with viral infection, comprising administering to said human or animal subject an effective amount of a compound of Formula (I) wherein: represents OR', NR'R, or R'wherein R'and R2 independently represent hydrogen, C16alkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl ; or R'and R2 together with the nitrogen atom to which they are attached form a 5 or 6 membered saturated cyclic group; RB represents C (O) R3 wherein R3 represents aryl or heteroaryl ; RC represents C16alkyl, aryl, heteroaryl or heterocyclyl ; R° represents hydrogen and RE represents hydrogen, OR4 or SR4, or R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; when RE is hydrogen, OR4or SR 4, RGand R Hare both hydrogen; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, R represents hydrogen and R"represents hydrogen, OR4 or SR4, or RG and R together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; R4 represents hydrogen, C, _6alkyl or aryl ; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, and RG and RH are both hydrogen or RG and R" together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, then RF represents O, S, NR5 or CR6R7, otherwise RF represents CR 6R7 ; R5 represents hydrogen, C16alkyl, arylalkyl or aryl ; R6 and R 7independently represent hydrogen, C16alkyl, arylalkyl or heteroarylalkyl ; RJ represents hydrogen, C »6alkyl, heterocyclylalkyl, arylalkyl or heteroarylalkyl ; and salts, solvates and enantiomers thereof; provided that when RA is OR'then R'is other than tertbutyl.
12. A method as claimed in claim 11 wherein the viral infection is HCV.
13. A compound as claimed in claim 1 wherein the medical therapy is the treatment of a viral infection.
14. A compound as claimed in claim 13 wherein the viral infection is HCV.
15. Use of a compound of Formula (I) wherein: RA represents OR', NR'R2, or R'wherein R'and R independently represent hydrogen, C16alkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl ; or R'and R2 together with the nitrogen atom to which they are attached form a 5 or 6 membered saturated cyclic group; RB represents C (O) R3 wherein R3 represents aryl or heteroaryl ; RC represents C, 6alkyl, aryl, heteroaryl or heterocyclyl ; represents hydrogen and RE represents hydrogen, OR or SR4, or RD and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; when RE is hydrogen, OR4 or SR4, RG and RH are both hydrogen; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, RG represents hydrogen and R"represents hydrogen, OR4 or SR4, or RG and R"together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; R4 represents hydrogen, Chalky) or aryl ; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, and RG and RH are both hydrogen or RG and R" together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, then RF represents O, S, NR5 or CR6R, otherwise RF represents CR6R7 ; R5 represents hydrogen, Cl6alkyl, arylalkyl or aryl ; R6 and R7 independently represent hydrogen, C16alkyl, arylalkyl or heteroarylalkyl ; RJ represents hydrogen, Cl6alkyl, heterocyclylalkyl, arylalkyl or heteroarylalkyl ; and salts, solvates and enantiomers thereof ; provided that when RA is OR'then R'is other than tertbutyl, in the manufacture of a medicament for the treatment of a viral infection.
16. Use as claimed in claim 15, wherein the viral infection is HCV.
17. A pharmaceutical composition comprising a compound as claimed in any of claims 111 or a physiologically acceptable salt, solvate or enantiomer thereof in admixture with one or more physiological acceptable diluents or carriers.
18. A process for the preparation of compounds of Formula (I) as claimed in claim 1, comprising reaction of a compound of Formula (II) in which RA, RC, R°, RE, RF, RG, RH and RJ are as defined for Formula (I) with an acylating agent.
19. A process for the preparation of compounds of Formula (I) wherein RA is OH, comprising hydrolysis of a compound of Formula (V) wherein RA is OR1 and R1 is C16alkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl and RB, RC, RD, RE, RF, RG, RH and RJ are as defined in claim 1 for Formula (I), with an acid.
20. Intermediate compounds of Formula (II) wherein RA represents OR', NR'R2, or R'wherein R'and R independently represent hydrogen, C16alkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl ; or R'and R2 together with the nitrogen atom to which they are attached form a 5 or 6 membered saturated cyclic group; RC represents C1. 6alkyl, aryl, heteroaryl or heterocyclyl ; R° represents hydrogen and RE represents hydrogen, OR4 or SR4, or R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; when RE is hydrogen, OR4 or SR4, RG and RH are both hydrogen; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, R represents hydrogen and R"represents hydrogen, OR4 or SR4, or RG and R together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; R4 represents hydrogen, C16alkyl or aryl ; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, and RG and RH are both hydrogen or RG and R" together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, then RF represents O, S, NR5 or CR6R7, otherwise RF represents CR6R7 ; R5 represents hydrogen, C16alkyl, arylalkyl or aryl ; R6 und R7 independently represent hydrogen, C16alkyl, arylalkyl or heteroarylalkyl ; R''represents hydrogen, C16alkyl, heterocyclylalkyl, arylalkyl or heteroarylalkyl ; provided that i) when RA is OR'and OR'is OH, and Rc is 4fluorophenyl, 2, 4dichlorophenyl, 2furanyl, 4carboxymethylphenyl, 3indolyl, 4 methoxyphenyl, 4 (dimethylamino) phenyl, 2thienyl, 2pyrrolyl or 2pyridyl, and R° and RE together with the carbon atom to which they are attached form a carbonyl group, and RF is 4bromophenyl, phenyl or methyl, and RG and RH together with the carbon atom to which they are attached form a carbonyl group, then RJ is other than (1 Himidazol5yl) methyl, and ii) a compound of Formula (II) is other than rel(3aS,6aR)1((1Himidazol5yl)methyl)3(2furanyl)octahydro4,6dioxopyrrolo [3,4 c] pyrrole1carboxylic acid; or rel(3aS,6aR)1((1Himidazol5yl)methyl)3(2pyrryl)octahydro4,6dioxopyrrolo [3,4 c] pyrrole1carboxylic acid ; or rel(1S, 3R, 3aS, 6aR)1methyl3 (4methoxyphenyl)5phenyloctahydro4, 6dioxo pyrrolo [3,4c] pyrrole1carboxylic acid; or rel (1S, 3R, 3aS, 6aR)1methyl3 (4nitrophenyl)5phenyloctahydro4, 6dioxo pyrrolo [3,4c] pyrrole1carboxylic acid; or rel(1S, 3R, 3aS, 6aR)1benzyl3(4methoxyphenyl)5phenyloctahydro4,6dioxo pyrrolo [3,4c] pyrrole1carboxylic acid; or rel(1S, 3R, 3aS, 6aR)1benzyl3 (4nitrophenyl)5phenyloctahydro4, 6dioxo pyrrolo[3, 4c] pyrrole1carboxylic acid; or rel(1S, 3R, 3aS, 6aR)1(2methylpropyl)3(4methoxyphenyl)5methyloctahydro4, 6 dioxopyrrolo [3, 4c]pyrrole1carboxylic acid; or rel (1S, 3R, 3aS, 6aR)1 (2methylpropyl)3 (4nitrophenyl)5methyloctahydro4, 6dioxo pyrrolo [3,4c] pyrrole1carboxylic acid; or rel(1S, 3R, 3aS, 6aR)1methyl3 (4methoxyphenyl)5methyloctahydro4, 6dioxo pyrrolo [3,4c] pyrrole1carboxylic acid; or rel (1S, 3R, 3aS, 6aR)1methyl3(4nitrophenyl)5methyloctahydro4,6dioxo pyrrolo [3,4c] pyrrole1carboxylic acid.
21. Intermediate compounds of Formula (V) wherein RA is OR1 and R1 is C16alkyl, aryl, hetroaryl, arylalkyl or heteroarylalkyl and RB, RC, RD, RE, RF, RG, RH and RJ are as defined above for Formula (I).
Description:
ACYL BICYCLIC DERIVATIVES OF PYRROL FIELD OF THE INVENTION The present invention relates to novel acyl bicyclic derivatives of pyrrole useful as anti- viral agents. Specifically, the present invention involves novel HCV inhibitors.

BACKGROUND OF THE INVENTION In the US, an estimated 4.5 million Americans are chronically infected with HCV.

Although only 30% of acute infections are symptomatic, greater than 85% of infected individuals develop chronic, persistent infection. Treatment costs for HCV infection have been estimated at $5.46 billion for the US in 1997. Worldwide over 200 million people are estimated to be infected chronically. HCV infection is responsible for 40-60% of all chronic liver disease and 30% of all liver transplants. Chronic HCV infection accounts for 30% of all cirrhosis, end-stage liver disease, and liver cancer in the U. S.

The CDC estimates that the number of deaths due to HCV will minimally increase to 38,000/year by the year 2010.

Due to the high degree of variability in the viral surface antigens, existence of multiple viral genotypes, and demonstrated specificity of immunity, the development of a successful vaccine in the near future is unlikely. Alpha-interferon (alone or in combination with ribavirin) has been widely used since its approval for treatment of chronic HCV infection. However, adverse side effects are commonly associated with this treatment: flu-like symptoms, leukopenia, thrombocytopenia, depression from interferon, as well as anemia induced by ribavirin (Lindsay, K. L. (1997) Hepatology 26 (suppl 1): 71S-77S). This therapy remains less effective against infections caused by HCV genotype 1 (which constitutes-75% of all HCV infections in the developed markets) compared to infections caused by the other 5 major HCV genotypes. Unfortunately, only ~50-80% of the patients respond to this treatment (measured by a reduction in serum HCV RNA levels and normalization of liver enzymes) and, of those treated, 50- 70% relapse within 6 months of cessation of treatment. Recently, with the introduction of pegylated interferon, both initial and sustained response rates have improved substantially, and combination treatment of Peg-IFN with ribavirin constitutes the gold standard for therapy. However, the side effects asociated with combination therapy and the impaired response in patients with genotype 1 present opportunities for improvement in the management of this disease.

First identified by molecular cloning in 1989 (Choo, Q-L et al. (1989) Science 244: 359- 362), hepatitis C virus (HCV) is now widely accepted as the most common causative agent of post-transfusion non A, non-B hepatitis (NANBH) (Kuo, G et a/. (1989) Science 244: 362-364). Due to its genome structure and sequence homology, this virus was assigned as a new genus in the Flaviviridae family. Like the other members of the Flaviviridae, such as flaviviruses (e. g. yellow fever virus and Dengue virus types 1-4)

and pestiviruses (e. g. bovine viral diarrhea virus, border disease virus, and classic swine fever virus) (Choo, Q-L et a/. (1989) Science 244: 359-3; Miller, R. H. and R. H. Purcell (1990) Proc. Natl. Acad. Sci. USA 87: 2057-2061), HCV is an enveloped virus containing a single strand RNA molecule of positive polarity. The HCV genome is approximately 9.6 kilobases (kb) with a long, highly conserved, noncapped 5'nontranslated region (NTR) of approximately 340 bases which functions as an internal ribosome entry site (IRES) (Wang CY et al.'An RNA pseudoknot is an essential structural element of the internal ribosome entry site located within the hepatitis C virus 5'noncoding region' [Article] Rna-A Publication of the Rna Society. 1 (5): 526-537,1995 Jul.). This element is followed by a region which encodes a single long open reading frame (ORF) encoding a polypeptide of-3000 amino acids comprising both the structural and nonstructural viral proteins.

Upon entry into the cytoplasm of the cell, this RNA is directly translated into a polypeptide of-3000 amino acids comprising both the structural and nonstructural viral proteins. This large polypeptide is subsequently processed into the individual structural and nonstructural proteins by a combination of host and virally-encoded proteinases (Rice, C. M. (1996) in B. N. Fields, D. M. Knipe and P. M. Howley (eds) Virology 2"d Edition, p931-960; Raven Press, N. Y. ). Following the termination codon at the end of the long ORF, there is a 3'NTR which roughly consists of three regions: an-40 base region which is poorly conserved among various genotypes, a variable length poly (U)/polypyrimidine tract, and a highly conserved 98 base element also called the"3' X-tail" (Kolykhalov, A. et al. (1996) J. Virology 70: 3363-3371; Tanaka, T. et al. (1995) Biochem Biophys. Res. Commun. 215: 744-749; Tanaka, T. et aL (1996) J. Virology 70: 3307-3312; Yamada, N. et al. (1996) Virology 223: 255-261). The 3'NTR is predicted to form a stable secondary structure which is essential for HCV growth in chimps and is believed to function in the initiation and regulation of viral RNA replication.

The NS5B protein (591 amino acids, 65 kDa) of HCV (Behrens, S. E. et a/. (1996) EMBO J. 15: 12-22), encodes an RNA-dependent RNA polymerase (RdRp) activity and contains canonical motifs present in other RNA viral polymerases. The NS5B protein is fairly well conserved both intra-typically (-95-98% amino acid (aa) identity across 1b isolates) and inter-typically (-85% aa identity between genotype 1a and 1b isolates).

The essentiality of the HCV NS5B RdRp activity for the generation of infectious progeny virions has been formally proven in chimpanzees (A. A. Kolykhalov et a/. (2000) Journal of Virology, 74 (4): 2046-2051). Thus, inhibition of NS5B RdRp activity (inhibition of RNA replication) is predicted to cure HCV infection.

Based on the foregoing, there exists a significant need to identify synthetic or biological compounds for their ability to inhibit HCV.

Certain bicyclic compounds have been synthesised and disclosed in the prior art; some of these compounds have been shown to have utility in a number of therapeutic areas, as outlined below.

B. Henkel et al. (2000) Bioorganic & Medicinal Chemistry Letters 10: 975-977 relates to a stereo-random synthesis of highly functionalised proline analogues by azomethine cycloaddition. It specifically discloses several 1, 5-diazobicyclo [3.3. 0] octane-2-carboxylic acid analogues of proline, but no therapeutic use is mentioned.

A. J. Bicknell et al. (1996) Bioorganic & Medicinal Chemistry Letters 6 (20): 2441-2444 similarly relates to the synthesis of a highly functionalised rigid template by solid phase azomethine ylide cycloaddition. It specifically discloses several 1,5- diazobicyclo [3.3. 0] octane-2-carboxylic acids, but no therapeutic use is mentioned.

WO 00/18772 A1 relates to condensed imidazolidinones as tRNA synthetase inhibitors.

It generically discloses a group of bicyclic compounds which exhibit tRNA synthetase inhibition.

US 5231083 (equivalent to DE 3926606) discloses compounds possessing certain bicylic systems having utility for the treatment of cardiac and of vascular hypertrophy and/or hyperplasia.

WO 02/18369 A2 discloses peptidometric compounds possessing certain bicyclic systems having utility as protease inhibitors, including as hepatitis C virus NS3 protease inhibitors.

WO 02/055491 A2 discloses 1,2-disubstituted cyclic matrix metalloproteases and tumour necrosis factor (TNF)-a inhibitors, which have utility in pathological conditions such as osteo-and rheumatiod arthritis, certain ulcerations, tumour metastasis or invasion, periodontal disease and bone disease.

The present invention discloses certain bicyclic compounds having potential to inhibit NS5B HCV polymerase activity and therefore having utility in the treatment of viral infection, especially HCV infection.

SUMMARY OF THE INVENTION The present invention involves compounds represented hereinbelow, pharmaceutical compositions comprising such compounds and use of the present compounds in treating viral infection, especially HCV infection.

DETAILED DESCRIPTION OF THE INVENTION The present invention provides compounds of Formula (I) :

wherein: RA represents OR', NR1R2, or R1 wherein R1 und R2 independently represent hydrogen, C1-6alkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl ; or R'and R2 together with the nitrogen atom to which they are attached form a 5 or 6 membered saturated cyclic group; RB represents C (O) R3 wherein R3 represents aryl or heteroaryl ; RC represents C1-6alkyl, aryl, heteroaryl or heterocyclyl ; represents hydrogen and RE represents hydrogen, OR4 or SR4, or RD and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; when RE is hydrogen, OR4 or SR4, R and R"are both hydrogen; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, R represents hydrogen and R"represents hydrogen, OR or SR4, or RG and RH together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; R4 represents hydrogen, C1-6alkyl or aryl ; when RD and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, and RG and R"are both hydrogen or RG and RH together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, then RF represents O, S, NR5 or CR6R7, otherwise RF represents CR6R7 ; R5 represents hydrogen, C1-6alkyl, arylalkyl or aryl ; R6 and R7 independently represent hydrogen, C1-6alkyl, arylalkyl or heteroarylalkyl ; RJ represents hydrogen, C1-6alkyl, hetrocyclylalkyl, arylalkyl or heteroarylalkyl ;

and salts, solvates and enantiomers thereof; provided that when RA is OR'then R'is other than tert-butyl, for use in medical therapy.

Thus, there is provided as one aspect of the present invention a compound of formula (I) or a physiologically acceptable salt, solvate or enantiomer thereof for use in human or veterinary medical therapy, particularly in the treatment of viral infection, particularly HCV infection.

It will be appreciated that reference herein to treatment includes, but is not limited to prevention, retardation, prophylaxis, therapy and cure of the disease. It will further be appreciated that references herein to treatment or prophylaxis of HCV infection includes treatment or prophylaxis of HCV-associated disease such as liver fibrosis, cirrhosis and hepatocellular carcinoma.

According to another aspect of the invention, there is provided the use of a compound of formula (I) or a physiologically acceptable salt, solvate or enantiomer thereof in the manufacture of a medicament for the treatment of viral infection, particularly HCV infection.

In a further aspect of the invention, there is provided a method for the treatment of a human or animal subject with viral infection, particularly HCV infection, which method comprises administering to said human or animal subject an effective amount of a compound of formula (I) or a physiologically acceptable salt, solvate or enantiomer thereof.

In another aspect of the invention, there is provided novel compounds of Formula (I), represented by Formula (A) wherein: RA represents OR', NR'R2, or R'wherein R'and R2 independently represent hydrogen, C16alkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl ; or R'and R2 together with the nitrogen atom to which they are attached form a 5 or 6 membered saturated cyclic group;

RB represents C (O) R3 wherein R3 represents aryl or heteroaryl ; RC represents C1-6alkyl, aryl, heteroaryl or heterocyclyl ; R° represents hydrogen and RE represents hydrogen, OR4 or SR4, or R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; when RE is hydrogen, OR4 or SR4, RG and RH are both hydrogen; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, R represents hydrogen and RH represents hydrogen, OR4 or SR4, or RG and R"together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; R4 represents hydrogen, C1-6alkyl or aryl ; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, and RG and R"are both hydrogen or RG and R" together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, then RF represents O, S, NR5 or CR6R7, otherwise RF represents CR 6R7 ; R5 represents hydrogen, C1-6alkyl, arylalkyl or aryl ; R6 and R7 independently represent hydrogen, C1-6alkyl, arylalkyl or heteroarylalkyl ; R''represents hydrogen, C1-6alkyl, hetrocyclyalkyl, arylalkyl or heteroarylalkyl ; and salts, solvates and enantiomers thereof; provided that i) when RA is OR'then R'is other than tert-butyl, and ii) a compound of Formula (A) is other than rel-(3aS,6aR)-1-((1H-imidazol-5-yl)methyl)-2-(cyclopropylben zoyl)-3-(4-methoxyphenyl)- 5-methyl-octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel- (1S, 3R, 3aS, 6aR)-1-methyl-2-benzoyl-3- (4-methoxyphenyl)-5-phenyl-octahydro-4, 6- dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or

rel-(1 S, 3R, 3aS, 6aR)-1-methyl-2-benzoyl-3-(4-nitrophenyl)-5-methyl-octahydro -4, 6- dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel- (1S, 3R, 3aS, 6aR)-1-benzyl-2-(phenylethanoyl)-3-(4-methoxyphenyl)-5-methy l- octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel-(1 S, 3R, 3aS, 6aR)-1-(2-methylpropyl)-2-ethanoyl-3-(4-methoxyphenyl)-5-met hyl- octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or re/-(1 S, 3R, 3aS, 6aR)-1-methyl-2-ethanoyl-3-(4-methoxyphenyl)-5-methyl-octahy dro-4, 6- dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid.

In one group of compounds of Formula (I), RA represents OR'or R'wherein R'is hydrogen, or RA represents NR1R2 wherein R'and R2 are as defined in Formula (I) above, and RB, RC, R°, RE, RF, RG and RH are as defined in Formula (I) above.

In another group of compounds of Formula (I), when R° represents hydrogen; RE represents hydrogen, OR4 or SR4 ; RF represents CR6R7 ; RG represents hydrogen; R" represents hydrogen and RA, RB and RJ are as defined in Formula (I) above, then Rc represents aryl, heteroaryl or heterocyclyl.

In one group of compounds of Formula (A), RA represents OR'or R'wherein R'is hydrogen, or RA represents NR'R2 wherein R'and R2 are as defined in Formula (A) above, and RB, RC, RD, RE, RF, RG and R"are as defined in Formula (A) above.

In another group of compounds of Formula (A), when RD represents hydrogen; RE represents hydrogen, OR4 or SR4 ; RF represents CR6R7 ; RG represents hydrogen; R" represents hydrogen and RA, RB and RJ are as defined in Formula (A) above, then Rc represents aryl, heteroaryl or heterocyclyl.

Preferably, the ring junction in Formula (I) is cis-fused, as shown in Formula (la) : It will be appreciated by the person skilled in the art that Formula (la) indicates the relative stereochemistry of the two chiral centres at the ring junction.

In another aspect of the invention, there is provided compounds of Formula (I) represented by Formula (lb) :

wherein: RA represents OR', NR1R2, or R1 wherein R1 and R2 independently represent C1-6alkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl ; or R'and R2 together with the nitrogen atom to which they are attached form a 5 or 6 membered saturated cyclic group; RB represents C (O) R3 wherein R3 represents C16alkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl ; RC represents C1-6alkyl, aryl, hetroaryl or heterocyclyl ; R° represents hydrogen and RE represents hydrogen, OR4 or SR4, or R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; when RE is hydrogen, OR4 or SR4, RG and R"are both hydrogen; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, RG represents hydrogen and R"represents hydrogen, OR4 or SR4, or RG and R"together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; R4 represents hydrogen, C1-6alkyl or aryl ; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, and RG and R"are both hydrogen or RG and R" together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, then RF represents O, S, NR5 or CR6R7, otherwise RF represents CR6R7 ; R5 represents hydrogen, C, 6alkyl, arylalkyl or aryl ; R6 and R 7independently represent hydrogen, C1-6alkyl, arylalkyl or heteroarylalkyl ; R''represents hydrogen, C1-6alkyl, heterocyclyalkyl, arylalkyl or heteroarylalkyl ;

and salts and solvates thereof; provided that when RA is OR'then R'is other than tert-butyl.

In yet another aspect of the invention, there is provided compounds of Formula (I) represented by Formula (Ic) : wherein: RA represents OH; RB represents C (O) R3 wherein R3 represents C1-6alkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl ; RC represents C1-6alkyl, aryl, heteroaryl or heterocyclyl ; R° represents hydrogen and RE represents hydrogen, OR4 or SR4, or R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; when RE is hydrogen, OR4 or SR4, R and RH are both hydrogen; when RD and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, R represents hydrogen and R"represents hydrogen, OR4 or SR4, or RG and RH together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; R4 represents hydrogen, C1-6alkyl or aryl ; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, and RG and RH are both hydrogen or RG and R" together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, then RF represents O, S, NR5 or CR6R7, otherwise RF represents CR6R ; R5 represents hydrogen, Chalky), arylalkyl or aryl ;

R6 and R 7independently represent hydrogen, C1-6alkyl, arylalkyl or heteroarylalkyl ; R''represents hydrogen, C1-6alkyl, heterocyclylalkyl, arylalkyl or heteroarylalkyl ; and salts and solvates thereof.

In yet another aspect of the invention, there is provided compounds of Formula (I) represented by Formula (Id) : wherein: RA represents OR', NR'R2, or R'wherein R'and R2 independently represent C1-6alkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl ; or R1 and R2 together with the nitrogen atom to which they are attached form a 5 or 6 membered saturated cyclic group; RB represents C (O) R3 wherein R3 represents aryl or heteroaryl ; RC represents C1-6alkyl, aryl, heteroaryl or heterocyclyl ; R° represents hydrogen and RE represents hydrogen, OR4 or SR4, or R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; when RE is hydrogen, oR4 or SR4, RG and RH are both hydrogen; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, RG represents hydrogen and R"represents hydrogen, OR4 or SR4, or RG and R together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; R4 represents hydrogen, C1-6alkyl or aryl ; when RD and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, and RG and R"are both hydrogen or RG and R" together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, then RF represents O, S, NR5 or CR6R7, otherwise R represents CR6R7 ; R5 represents hydrogen, C16alkyl, arylalkyl or aryl ; R6 and R7 independently represent hydrogen, C1-6alkyl, arylalkyl or heteroarylalkyl ; RJ represents hydrogen, Cl-6alkyl, heterocyclylalkyl, arylalkyl or heteroarylalkyl ; and salts and solvates thereof; provided that when RA is OR'then R'is other than tert-butyl, and i) when RA is OR'then R'is other than tert-butyl, and ii) a compound of Formula (Id) is other than rel-(3aS,6aR)-1-((1H-imidazol-5-yl)methyl)-2-(cyclopropylben zoyl)-3-(4-methoxyphenyl)- 5-methyl-octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel-(1S, 3R, 3aS, 6aR)-1-methyl-2-benzoyl-3- (4-methoxyphenyl)-5-phenyl-octahydro-4, 6- dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel-(1 S, 3R, 3aS, 6aR)-1-methyl-2-benzoyl-3-(4-nitrophenyl)-5-methyl-octahydro -4, 6- dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel-(1S, 3R, 3aS, 6aR)-1-benzyl-2-(phenylethanoyl)-3-(4-methoxyphenyl)-5-methy l- octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel-(1S, 3R, 3aS, 6aR)-1-(2-methylpropyl)-2-ethanoyl-3-(4-methoxyphenyl)-5-met hyl- octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel-(1S, 3R, 3aS, 6aR)-1-methyl-2-ethanoyl-3-(4-methoxyphenyl)-5-methyl-ocatah ydro-4, 6- dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid.

In yet another aspect of the invention, there is provided compounds of Formula (I) represented by Formula (le) : wherein: RA represents OH;

RB represents C (O) R3 wherein R3 represents aryl or heteroaryl ; RC represents C16alkyl, aryl, heteroaryl or heterocyclyl ; R° represents hydrogen and RE represents hydrogen, OR4 or SR4, or R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; when RE is hydrogen, OR4 or SR4, RG and RH are both hydrogen; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, RG represents hydrogen and R"represents hydrogen, OR4 or SR4, or RG and RH together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group; R4 represents hydrogen, C1-6alkyl or aryl ; when R° and RE together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, and RG and Rare both hydrogen or RG and R" together with the carbon atom to which they are attached form a carbonyl group or a thiocarbonyl group, then RF represents O, S, NR5 or CR6R7, otherwise RF represents CR6R7 ; R5 represents hydrogen, Cl-6alkyl, arylalkyl or aryl ; R and R 7independently represent hydrogen, C1-6alkyl, arylalkyl or heteroarylalkyl ; R1 represents hydrogen, C1-6alkyl, heterocyclyalkyl, arylalkyl or heteroarylalkyl ; and salts and solvates thereof; provided that when RA is OR'then R'is other than terf-butyl, and i) when RA is OR'then R'is other than tert-butyl, and ii) a compound of Formula (le) is other than rel-(3aS,6aR)-1-((1H-imidazol-5-yl)methyl)-2-(cyclopropylben zoyl)-3-(4-methoxyphenyl)- 5-methyl-octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel- (1S, 3R, 3aS, 6aR)-1-methyl-2-benzoyl-3-(4-methoxyphenyl)-5-phenyl-octahyd ro-4, 6- dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel-(1S, 3R, 3aS, 6aR)-1-methyl-2-benzoyl-3-(4-nitrophenyl)-5-methyl-octahydro -4, 6- dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or

rel-(1S, 3R, 3aS, 6aR)-1-benzyl-2-(phenylethanoyl)-3-(4-methoxyphenyl)-5-methy l- octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel- (1S, 3R, 3aS, 6aR)-1-(2-methylpropyl)-2-ethanoyl-3-(4-methoxyphenyl)-5-met hyl- octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel-(1S, 3R, 3aS, 6aR)-1-methyl-2-ethanoyl-3-(4-methoxyphenyl)-5-methyl-octahy dro-4, 6- dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid.

The following R groups are preferred, where applicable, in respect of each of Formulae I, la, Ib, Ic, Id, le and A: Preferably, RA is OR', more preferably RA is OH; Preferably, R3 is aryl, more preferably R3 is phenyl, optionally substituted by halo, Cl- 6alkyl or C1-3alkoxy. Especially preferred is 4-tert-butylphenyl, optionally 3-substituted by halo, C1-3alkyl or C13alkoxy, especially bromo, chloro, methyl or methoxy; most preferably R3 is 4-tert-butylphenyl, 3-bromo-4-tert-butylphenyl or 4-tert-butyl-3- methoxyphenyl ; Preferably, RC represents C16alkyl, aryl or heteroaryl ; more preferably Rc represents heteroaryl, especially preferred are pyridin-2-yl, pyrazin-2-yl, 1, 3-thiazol-2-yl, 5-methyl- 1, 3-thiazol-2-yl or 1, 3-thiazol-4-yl ; most preferred are Rc is 1, 3-thiazol-2-yl, 5-methyl-1, 3- thiazol-2-yl or pyridin-2-yl ; Preferably, R° and RE together with the carbon atom to which they are attached form a carbonyl group; Preferably, RG and RH are both hydrogen or RG and Together with the carbon atom to which they are attached form a carbonyl group; Preferably, RF is O, NR5 or CR6R7, more preferably RF is O, NCH3, N-benzyl, CH2 or C (CH3) 2 ; Preferably, RJ is C16alkyl, more preferably RJ is isobutyl.

It is to be understood that the present invention covers all combinations of suitable, convenient and preferred groups described herein.

As used herein,"alkyl"refers to an optionally substituted hydrocarbon group. The alkyl hydrocarbon group may be linear, branched or cyclic, saturated or unsaturated. Where the alkyl hydrocarbon group is cyclic, it will be understood that there will be a minimum of 3 carbon atoms in the group. Preferably, the group is saturated. Preferred alkyl moieties are C1-4alkyl. Optional subsituents include C16alkyl, halo, OR8, C (O) NR9R'°,

C02R3, NR9R10, NHC (O) R3, NHCO2R3, NHC (O) NR'R2, S02NR'R, S02R3, nitro, oxo, and heterocyclyl.

R8 represents hydrogen, C16alkyl, arylalkyl, or heteroarylalkyl ; R9 and R10 are independently selected from hydrogen, Chalky), aryl and heteroaryl.

As used herein,"aryl"refers to an optionally substituted aromatic group with at least one ring having a conjugated pi-electron system, containing up to two conjugated or fused ring systems."Aryl"includes carbocyclic aryl and biaryl groups, all of which may be optionally substituted. Preferred"aryl"moieties are C614aryl. Preferred"aryl"moieties are unsubstituted, monosubstituted, disubstituted or trisubstituted phenyl. Preferred "aryl"substituents are selected from the group consisting of C1-6alkyl, halo, OR8, C (O) NR9R'°, CO2R3, NR9R10, NHC (O) R3, NHC02R3, NHC (O) NR'R2, S02NR'R2, SO2R#, nitro, heterocyclyl, OC14alkyl, CF3, pyridine and phenyl.

As used herein,"heteroaryl"refers to an optionally substituted, 5 or 6 membered, aromatic group comprising one to four heteroatoms selected from N, O and S, with at least one ring having a conjugated pi-electron system, containing up to two conjugated or fused ring systems. Preferred"heteroaryl"moieties are unsubstituted, monosubstituted, disubstituted or trisubstituted thienyl and thiazolyl. Preferred "heteroaryl"substituents are selected from the group consisting of Chalky), halo, OR8, C (O) NR9R10, C02R3, NR9R10, NHC (O) R3, NHC02R3, NHC (O) NR'R2, SO2NR1R2, so2R3, nitro, heterocyclyl, OC14alkyl, CF3, pyridine and phenyl.

As used herein,"heterocyclic","heterocyclyl"and"5 or 6 membered saturated cyclic group"refer to an optionally substituted, 5 or 6 membered, saturated cyclic hydrocarbon group containing one to four heteroatoms selected from N, optionally substituted by hydrogen, C16alkyl, C (O) R3, SO2R3, aryl or heteroaryl ; O ; and S, optionally substituted by one or two oxygen atoms.

Preferred compounds useful in the present invention are selected from the group consisting of: rel- (1 S, 3R, 3aS, 6aR)-1-Isobutyl-2- (4-tert-butylbenzoyl)-3- (1, 3-thiazol-2-yl)-5-propyl- octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; rel- (1 S, 3R, 3aS, 6aR)-1-Isobutyl-2- (4-terf-butylbenzoyl)-3- (1, 3-thiazol-2-yl)-5-benzyl- octahydro-4, 6-dioxo-pyrrolo [3, 4-c] pyrrole-1-carboxylic acid ; rel- (1S, 3R, 3aS, 6aR)-1-Isobutyl-2-(4-tert-butylbenzoyl)-3-(1,3-thiazol-2-yl) -5-methyl- octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid ; rel- (1 S, 3R, 3aS, 6aR)-1-Isobutyl-2- (4-tert-butylbenzoyl)-3- (1, 3-thiazol-2-yl)-octahydro-4- oxo-cyclopenta [c] pyrrole-1-carboxylic acid; rel-(3aR, 4S, 6R,6aS)-4-Isobutyl-5-(4-tert-butylbenzoyl)-6-(1,3-thiazol-2- yl)-hexahydro- furo [3,4-c] pyrrol-1-oxo-4-carboxylic acid;

rel- (1 S, 3R, 3aS, 6aR)-1-Isobutyl-2- (3-methoxy-4-tert-butylbenzoyl)-3- (1, 3-thiazol-2-yl)- octahydro-4-oxo-cyclopenta [c] pyrrole-1-carboxylic acid; rel- (1S, 3R, 3aS, 6aR)-1-lsobutyl-2-(3-bromo-4-teff-butylbenzoyl)-3-(1, 3-thiazol-2-yl)-5- propyl-octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid ; re/- (1 S, 3R, 3aS, 6aR)-1-lsobutyl-2-(3-bromo-4-teff-butylbenzoyl)-3-(1, 3-pyridin-2-yl)-5- propyl-octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid ; rel (1S, 3R, 3aS, 6aR)-1-Isobutyl-2- (4-tert-butylbenzoyl)-3- (pyridin-2-yl)-5-propyl- octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; rel- (1 S, 3R, 3aS, 6aR)-1-Isobutyl-2- (3-methoxy-4-tert-butylbenzoyl)-3- (1, 3-thiazol-2-yl)- octahydro-4-oxo-5, 5-dimethyl-cyclopenta [c] pyrrole-1-carboxylic acid ; rel- (1 S, 3R, 3aS, 6aR)-1-Isobutyl-2- (3-methoxy-4-tert-butylbenzoyl)-3- (5-methyl-1, 3- thiazol-2-yl)-octahydro-4-oxo-cyclopenta [c] pyrrole-1-carboxylic acid ; and salts, solvates and enantiomers thereof.

Also included in the present invention are pharmaceutical acceptable salt complexes.

The present invention also covers the physiologically acceptable salts of the compounds of formula (I). Suitable physiologically acceptable salts of the compounds of formula (1) include acid salts, for example sodium, potassium, calcium, magnesium and tetraalkylammonium and the like, or mono-or di-basic salts with the appropriate acid for example organic carboxylic acids such as acetic, lactic, tartaric, malic, isethionic, lactobionic and succinic acids; organic sulfonic acids such as methanesulfonic, ethanesulfonic, benzenesulfonic and p-toluenesulfonic acids and inorganic acids such as hydrochloric, sulfuric, phosphoric and sulfamic acids and the like.

The present invention also relates to solvates of the compounds of Formula (I), for example hydrates.

It will be appreciated that the compounds of the present invention may contain one or more asymmetric carbon atoms and may exist in racemic and optically active forms. All of these compounds and diastereomers are contemplated to be within the scope of the present invention.

It will further be appreciated that certain compounds of the present invention may exist in different tautomeric forms. All tautomers are contemplated to be within the scope of the present invention.

Compounds of Formula (I) may be prepared by reaction of a compound of Formula (II)

in which RA, RC, RD, RE, RF, RG, RH and RJ are as defined above for Formula (I) with a suitable acylating agent; for example (R3CO) 20 or R3C (O)-X, wherein X is a halo atom, preferably chloro or bromo. Preferably the reaction is carried out in a suitable solvent, for example dichloromethane, tetrahydrofuran, acetonitrile or dimethylformamide in the presence of a suitable base, for example triethylamine, pyridine or diisopropylethylamine.

Compounds of Formula (II) may be prepared by reaction of a compound of Formula (III) wherein RA, RC, and RJ are as defined for Formula (I) above; with a compound of Formula (IV) wherein RD, RE, RF, RG and RH are as defined for Formula (I), providing that RD and RE together with the carbon atom to which they are attached, form a carbonyl group.

Preferably, the reaction is carried out in a suitable solvent, for example tetrahydrofuran, dichloromethane, acetonitrile or dimethylformamide in the presence of a Lewis acid catalyst, such as lithium bromide or silver acetate and a base, such as triethylamine or diisopropylethylamine.

Alternatively, compounds of Formula (i) wherein RA is OH may be prepared from a compound of Formula (V) wherein RA is OR1 and R1 is C1-6alkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl and RB, RC, RD, RE, RF, RG, RH and RJ are as defined above for Formula (I) ; for example

when R1 is tert-butyl, by treatment with an appropriate acid, for example trifluoroacetic acid. Suitably, the reaction is carried out in a solvent, for example dichloromethane.

Preferably, the temperature is in the range 0 to 50°C, more preferably 15 to 30°C.

Compounds of Formula (V) may be prepared by reaction of a compound of Formula (Ila) in which RA, RC, R°, RE, RF, RG, RH and RJ are as defined above for Formula (V) with a suitable acylating agent; for example (R3CO) 20 or R3C (O)-X, wherein X is a halo atom, preferably chloro or bromo. Preferably the reaction is carried out in a suitable solvent, for example dichloromethane, tetrahydrofuran, acetonitrile or dimethylformamide in the presence of a suitable base, for example triethylamine, pyridine or diisopropylethylamine.

Compounds of Formula (Ila) may be prepared by reaction of a compound of Formula (Illa) wherein RA, RC, and RJ are as defined for Formula (V) above; with a compound of Formula (IVa) wherein R°, RE, RF, RG and RH are as defined for Formula (V), providing that RD and RE together with the carbon atom to which they are attached, form a carbonyl group.

Preferably, the reaction is carried out in a suitable solvent, for example tetrahydrofuran, dichloromethane, acetonitrile or dimethylformamide in the presence of a Lewis acid catalyst, such as lithium bromide or silver acetate and a base, such as triethylamine or diisopropylethylamine.

Compounds of Formula (I) in which RE is OH may be prepared from compounds of Formula (I) in which RE and RD together with the carbon atom to which they are attached form a carbonyl group by treatment with a suitable reducing agent, such as lithium

borohydride, diisobutylaluminium hydride, sodium borohydride with boron trifluoride etherate, in a suitable solvent such as tetrahydrofuran, diethylether or dichloromethane.

Compounds of Formula (II) in which RE is OH may be prepared from compounds of Formula (II) in which RE and RD together with the carbon atom to which they are attached form a carbonyl group by treatment with a suitable reducing agent, such as lithium borohydride, diisobutylaluminium hydride, sodium borohydride with boron trifluoride etherate, in a suitable solvent such as tetrahydrofuran, diethylether or dichloromethane.

Compounds of Formula (I) in which RE is OR4, and R4 is Ci. alkyl or aryl, may be prepared from compounds of Formula (I) in which RE is OH by treatment with a suitable acid, such as hydrochloric acid or p-toluenesulphonic acid, and an alcohol R40H, in which R4 is Ci. alkyl or aryl, optionally in a suitable solvent such as tetrahydrofuran, diethylether or dichloromethane.

Compounds of Formula (II) in which RE is OR4, and R4 is C1-6alkyl or aryl may be prepared from compounds of Formula (II) in which RE is OH by treatment with a suitable acid, such as hydrochloric acid or p-toluenesulphonic acid, and an alcohol R40H, in which R4 is C16 alkyl or aryl, optionally in a suitable solvent such as tetrahydrofuran, diethylether or dichloromethane.

Compounds of Formula (III) and (IV) are known in the art or may be prepared by standard literature procedures.

Compounds of Formula (II) : i) in which when RA is OR'and OR'is OH, and Rc is 4-fluorophenyl, 2, 4-dichlorophenyl, 2-furanyl, 4-carboxymethylphenyl, 3-indolyl, 4- methoxyphenyl, 4- (dimethylamino) phenyl, 2-thienyl, 2-pyrrolyl or 2-pyridyl, and R° and RE together with the carbon atom to which they are attached form a carbonyl group, and RF is 4-bromophenyl, phenyl or methyl, and RG and Together with the carbon atom to which they are attached form a carbonyl group, then Ru ils other than (1 H-imidazol-5-yl) methyl, and ii) which are other than rel-(3aS,6aR)-1-((1H-imidazol-5-yl)methyl)-3-(2-furanyl)-oct ahydro-4,6-dioxo-pyrrolo [3,4- c] pyrrole-1-carboxylic acid; or re/-(3aS, 6aR)-1-((1 H-imidazol-5-yl) methyl)-3-(2-pyrryl)-octahydro-4, 6-dioXo-pyrrolo [3,4- c] pyrrole-1-carboxylic acid; or

rel-(1S, 3R, 3aS, 6aR)-1-methyl-3- (4-methoxyphenyl)-5-phenyl-octahydro-4, 6-dioxo- pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel- (1S, 3R, 3aS, 6aR)-1-methyl-3- (4-nitrophenyl)-5-phenyl-octahydro-4, 6-dioxo- pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel-(1S, 3R, 3aS, 6aR)-1-benzyl-3-(4-methoxyphenyl)-5-phenyl-octahydro-4,6-dio xo- pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel-(1S, 3R, 3aS, 6aR)-1-benzyl-3- (4-nitrophenyl)-5-phenyl-octahydro-4, 6-dioxo- pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel- (1S, 3R, 3aS, 6aR)-1- (2-methylpropyl)-3- (4-methoxyphenyl)-5-methyl-octahydro-4, 6- dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel- (1S, 3R, 3aS, 6aR)-1-(2-methylpropyl)-3-(4-nitrophenyl)-5-methyl-octahydro -4,6-dioxo- pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel-(1S, 3R, 3aS, 6aR)-1-methyl-3(4-methoxyphenyl)-5-methyl-octahydro-4,6-diox o- pyrrolo [3,4-c] pyrrole-1-carboxylic acid; or rel- (1S, 3R, 3aS, 6aR)-1-methyl-3(4-nitrophenyl)-5-methyl-octahydro-4,6-dioxo- pyrrolo [3,4-c] pyrrole-1-carboxylic acid. are novel compounds useful as intermediates in the synthesis of compounds of Formula (I).

Compounds of Formula (V) in which R1 is tert-butyl are novel compounds useful as intermediates in the synthesis of compounds of Formula (I).

With appropriate manipulation and protection of any chemical functionality, synthesis of compounds of Formula (I) is accomplished by methods analogous to those above and to those described in the Experimental section. Suitable protecting groups can be found, but are not restricted to, those found in T W Greene and P G M Wuts'Protective Groups in Organic Synthesis', 3rd Ed (1999), J Wiley and Sons.

EXAMPLES Intermediate 1 2- [N- (1, 3-Thiazol-2-ylmethylene) amino]-4-methylpentanoic acid, test-butyl ester

A stirred mixture of 2-amino-4-methyl-pentanoic acid tert-butyl ester, hydrochloride salt (5.00 g, 22.34 mmol), 1, 3-thiazole-2-carboxaldehyde (2.53 g, 22.34 mmol) and triethylamine (3.10 mL, 22.3 mmol) in dichloromethane (60 mL) was heated under reflux under nitrogen for 19 hours. The reaction mixture was allowed to cool to room temperature, washed twice with water, dried over Na2SO4 and evaporated to give the title compound as an oil.

'H NMR (CDCI3) : 8 8.46 (s, 1H), 7.94 (d, 1H), 7.44 (dd, 1H), 4.07 (dd, 1H), 1.89-1. 74 (m, 2H), 1.64-1. 52 (m, 1 H), 1.48 (s, 9H), 0.96 (d, 3H) and 0.90 (d, 3H).

Intermediate 2 rel- (1S, 3R, 3aS, 6aR)-1-Isobutyl-3- (1, 3-thiazol-2-yl)-5-propyl-octahydro-4, 6-dioxo- pyrrolo [3,4-c] pyrrole-1-carboxylic acid, tert butyl ester.

To a stirred solution of Intermediate 1 (2.05 g, 7.26 mmol) in anhydrous tetrahydrofuran (30 ml) under nitrogen, was added triethylamine (1.01 mi, 7.26 mmol) followed by lithium bromide (63mg, 7.26 mmol) and a solution of N-propylmaleimide (1.01 g, 7.26 mmol) in anhydrous tetrahydrofuran (20 ml). The mixture was stirred at ambient temperature overnight. Aqueous ammonium chloride was added with rapid stirring and the resulting mixture was extracted twice with ethyl acetate. The combined organic layers were dried over sodium sulphate and evaporated to give the title compound as a solid.

Mass spec (electrospray) m/z calcd for (C21H3, N404S + H) +: 422 Found: (M+H) +: 422 Intermediate 3 re/- (1S, 3R, 3aS, 6aR)-1-Isobutyl-3- (1, 3-thiazol-2-yl)-5-benzyl-octahydro-4, 6-dioxo- pyrrolo [3,4-c] pyrrole-1-carboxylic acid, teff butyl ester.

This was prepared following the procedure for Intermediate 2, replacing N- propylmaleimide with N-benzylmaleimide. The compound was purified by chromatography on silica gel using cyclohexane-ethyl acetate (4: 1 v/v) as eluent to provide the title compound as a solid.

Mass spec (electrospray) m/z calc for (C25H31 N304S + H) + : 470.

Found: (M+H) + : 470 Intermediate 4 rel- (1 S, 3R, 3aS, 6aR)-1-Isobutyl-3- (1, 3-thiazol-2-yl)-5-methyl-octahydro-4, 6-dioxo- pyrrolo [3,4-c] pyrrole-1-carboxylic acid, teit butyl ester.

This was prepared following the procedure for Intermediate 2, replacing N- propylmaleimide with N-methylmaleimide to provide the title compound as a solid.

Mass spec (electrospray) m/z calc for (CgH27N304S + H) + : 394.

Found: (M+H) + : 394 Intermediate 5 rel- (1S, 3R, 3aS, 6aR)-1-Isobutyl-3-(1,3-thiazol-2-yl)-octahydro-4-oxo- cyclopenta [c] pyrrole-1-carboxylic acid, ter butyl ester.

This was prepared following the procedure for Intermediate 2, replacing N- propylmaleimide with 2-cyclopentene-1-one, to provide the title compound as an oil.

Mass spec (electrospray) m/z calc for (C19H28N203S + H) + : 365.

Found: (M+H) + : 365.

Intermediate 6 rel-(3aR, 4S, 6R, 6aS)-4-Isobutyl-6-(1,3-thiazol-2-yl)-hexahydro-furo [3,4-c] pyrrole-1-oxo- 4-carboxylic acid, tert butyl ester.

This was prepared following the procedure for Intermediate 2, replacing N- propylmaleimide with 2- (5H)-furanone, to provide the title compound as a solid.

Mass spec (electrospray) m/z calc for (C18H26N204S + H) + : 367.

Found: (M+H) + : 367.

Intermediate 7 rel- (1 S, 3R, 3aS, 6aR)-1-Isobutyl-2-(4-tert-butylbenzoyl)-3-(1,3-thiazol-2-yl) -5-prop octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid, tert butyl ester.

To a stirred solution of Intermediate 2 (1.5 g, 3.56 mmol) in anhydrous chloroform (60 mL) was added triethylamine (0.74 mL, 5.34 mmol) and 4-tett-butyl-benzoyl chloride (1 mL, 5.34 mmol). This mixture was stirred at ambient temperature for 18 hours. The mixture was then washed with water and extracted with dichloromethane. The organic phase was dried (Na2SO4) and evaporated.

The residue was purified by chromatography on silica gel using cyclohexane-ethyl acetate (1: 1 v/v) as eluent to provide the title compound as a solid.

Mass spec (electrospray) m/z calcd for (C32H43N305S + H) + : 582 Found: (M+H) + = 582.

Intermediate 8 rel- (1S, 3R, 3aS, 6aR)-1-Isobutyl-2-(4-teff-butylbenzoyl)-3-(1, 3-thiazol-2-yl)-5-benzyl- octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid, tert butyl ester.

This was prepared following the procedure for Intermediate 7, replacing Intermediate 2 with Intermediate 3. The compound was purified by chromatography on silica gel using cyclohexane-ethyl acetate (4: 1 v/v) as eluent to provide the title compound as a solid.

Mass spec (electrospray) m/z calc for (C36H43N305S + H) + : 630.

Found: (M+H) + : 630 Intermediate 9 rel- (1S, 3R, 3aS, 6aR)-1-Isobutyl-2- (4-tert-butylbenzoyl)-3- (1, 3-thiazol-2-yl)-5-methyl- octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid, tert butyl ester.

This was prepared following the procedure for Intermediate 7 replacing Intermediate 2 with Intermediate 4. The compound was purified by chromatography on silica gel using cyclohexane-ethyl acetate (1: 1 v/v) as eluent to provide the title compound as a solid.

Mass spec (electrospray) m/z calc for (CgoH3gN3O5S + H) + : 554.

Found: (M+H) + : 554.

Intermediate 10 rel-(1 S, 3R, 3aS, 6aR)-1-Isobutyl-2-(4-tert-butylbenzoyl)-3-(1,3-thiazol-2-yl) -5-octahydro-4- oxo-cyclopenta [c] pyrrole-1-carboxylic acid, tert butyl ester.

This was prepared following the procedure for Intermediate 7, replacing Intermediate 2 with Intermediate 5. The compound was purified by chromatography on silica gel using cyclohexane-ethyl acetate (4: 1 v/v) as eluent to provide the title compound as a solid.

Mass spec (electrospray) m/z calc for (C3oH4oN204S + H) + : 525.

Found: (M+H) + : 525.

Intermediate 11 rel-(3aR, 4S, 6R, 6aS)-4-Isobutyl-5- (4-tert-butylbenzoyl)-6- (1, 3-thiazol-2-yi)-hexahydro- furo [3,4-c] pyrrol-1-oxo-4-carboxylic acid, tert butyl ester.

This was prepared following the procedure for Intermediate 7, replacing Intermediate 2 with Intermediate 6. The compound was purified by chromatography on silica gel using cyclohexane-ethyl acetate (3: 2 v/v) as eluent to provide the title compound as a solid.

Mass spec (electrospray) m/z calc for (C29H38N205S + H) + : 527.

Found: (M+H)+ : 527.

Intermediate 12 rel- (1S, 3R, 3aS, 6aR)-l-Isobutyl-2- (3-methoxy-4-teit-butylbenzoyl)-3- (1, 3-thiazol-2-yl)- octahydro-4-oxo-cyclopenta [c] pyrrole-1-carboxylic acid, tert butyl ester.

To a solution of Intermediate 5 (0.750 g, 2.06 mmol) in dichloromethane (15 mL) was added 3-methoxy-4-tert-butylbenzoyl chloride* (0.560 mg, 2.47 mmol) followed by triethylamine (0.36 mL, 2.58 mmol) and the mixture stirred at room temperature for 18 hours. The solvents were removed in vacuo and the residue purified by chromatography using a SPE cartridge (10g silica) and eluting with cyclohexane, then cyclohexane-ethyl acetate (3: 2, v/v). This afforded the title compound as a foam.

* {Synthesized from 4-teff-butyl-3-methoxybenzoic acid (J. Org. Chem, 26,1961, 1732- 1737)} MS calcd for (C31H42N205S + H) + : 555 MS found (electrospray) : (M+H) += 555 Intermediate 13 rel- (1S, 3R, 3aS, 6aR)-1-Isobutyl-2- (3-bromo-4-tert-butylbenzoyl)-3- (1, 3-thiazol-2-yl)-5- propyl-octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid, tert butyl ester.

To a stirred solution of Intermediate 2 (0.3 g, 0.71 mmol) in dry dichloromethane (2 mL) was added 3-bromo-4-teff-butylbenzoyl chloride* (0.215 g, 1.1 eq. ) dissolved in dry dichloromethane (3 mL), followed by triethylamine (0.123 mL, 0.89 mmol). This mixture was stirred at ambient temperature for 18 hours. The mixture was then diluted with dichloromethane (8 mL) and washed with water. The organic phase was dried (Na2SO4) and evaporated.

The residue was purified by chromatography on silica gel using cyclohexane-ethyl acetate (4: 1 v/v) as eluent to provide the title compound as a solid.

*Synthesised from 3-bromo-4-tert-butylbenzoic acid (Aust. J. Chem. (1990), 43 (5), 807- 14).

'H NMR (CDCI3) : s 7.36 (d, 1H), 7.25 (d, 1H), 7.17 (d, 1H), 7.14 (d, 1H), 7.04 (dd, 1H), 6.02 (d, 1H), 4.00 (t, 1H), 3.58 (d, 1H), 3.28 (m, 2H), 2.74 (dd, 1H), 2.13 (dd, 1H), 1.79 (m, 1H), 1.60 (s, 9H), 1.50 (m, 2H), 1.43 (s, 9H), 1.16 (d, 3H), 1.14 (d, 3H), 0.87 (t, 3H).

Intermediate 14 2- [N- (Pyridin-2-ylmethylene) amino]-4-methylpentanoic acid, ter-butyl ester A stirred mixture of 2-amino-4-methylpentanoic acid tert-butyl ester hydrochloride (5.00 g, 22.35 mmol), pyridine-2-carboxaldehyde (2.12 mL, 22.35 mmol) and triethylamine (3.11 mL, 22.35 mmol) in dichloromethane (75 mL) was heated under reflux under nitrogen for 2 hours. The reaction mixture was allowed to cool to room temperature, washed with water and brine, dried over MgS04 and evaporated to give the title compound as an oil. oh NMR (CDCI3) : 8 8.65 (ddd, 1H), 8.37 (s, 1H), 8.12 (dt, 1H), 7.75 (ddt, 1H), 7.34 (ddd, 1H), 4.05 (dd, 1H), 1.79-1. 85 (m, 2H), 1.58 (m, 1H), 1.47 (s, 9H), 0.95 (d, 3H) and 0.91 (d, 3H).

Intermediate 15 rel- (1S, 3R, 3aS, 6aR)-1-Isobutyl-3-(pyridin-2-yl)-5-propyl-octahydro-4,6-diox o-pyrrolo [3,4- c] pyrrole-1-carboxylic acid, tert butyl ester. This was prepared following the procedure for Intermediate 2, replacing Intermediate 1 with Intermediate 14. This afforded the title compound as a solid.

Mass spec (electrospray) m/z calc for (C23H33N304 + H) + : 416.

Found (M+H) + : 416.

Intermediate 16 rel- (1 S, 3R, 3aS, 6aR)-1-Isobutyl-2-(3-bromo-4-tert-butylbenzoyl)-3-(pyridin-2 -yl)-5-propyl- octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid, test butyl ester.

To a stirred solution of Intermediate 15 (0.269 g, 0.65 mmol) in dry dichloromethane (3 mL) was added 3-bromo-4-tert-butylbenzoyl chloride* (0.215 g, 1.1 eq. ) dissolved in dry dichloromethane (1 mL), followed by triethylamine (0.113 mL, 0.81 mmol). This mixture was stirred at ambient temperature for 2 days. The mixture was then diluted with dichloromethane (8 mL) and washed with water (5 mL). The organic phase was dried (Na2SO4) and evaporated.

The residue was purified by chromatography on silica gel using cyclohexane-ethyl acetate (4: 1, v/v) as eluent to provide the title compound as a solid.

'H NMR (CDCI3) : 8 81.4 (d, 1H), 7.70 (d, 1H), 7.45 (dt, 1H), 7.16 (d, 1H), 6.95-7. 04 (m, 3H), 5.67 (d, 1H), 4.00 (dd, 1H), 3.55 (d, 1H), 3.23 (m, 2H), 2.78 (dd, 1H), d. 13 (dd, 1H), 1.81 (m, 1H), 1.60 (s, 9H), 1.45-1. 55 (m, 2H), 1.37 (s, 9H), 1.16 (d, 3H), 1.15 (d, 3H), 0.83 (t, 3H).

Intermediate 17 rel-(1 S, 3R, 3aS, 6aR)-1-Isobutyl-2-(4-tert-butylbenzoyl)-3-(pyridin-2-yl)-5-p ropyl- octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid, tert butyl ester.

This was prepared following the procedure for Intermediate 16, replacing 3-bromo-4- tert-butylbenzoyl chloride with 4-tert-butylbenzoyl chloride. This afforded the title compound as a solid.

'H NMR (CDCI3) : 8 8.09 (d, 1H), 7.71 (d, 1H), 7.38 (dt, 1H), 7.05 (d, 2H), 6.97 (d, 2H), 6.88 (m, 1H), 5.77 (d, 1H), 3.99 (dd, 1H), 3.56 (d, 1H), 3.22 (m, 2H), 2.81 (dd, 1H), 2.12 (dd, 1H), 1.84 (m, 1H), 1.60 (s, 9H), 1.31-1. 46 (m, 2H), 1.17 (s, 9H), 1.16 (d, 3H), 1.14 (d, 3H), 0.82 (t, 3H).

Intermediate 18 rel- (1S, 3R, 3aS, 6aR)-1-Isobutyl-3- (1, 3-thiazol-2-yl)-octahydro-4-oxo-5, 5dimethyl- cyclopenta [c] pyrrole-1-carboxylic acid, toff butyl ester.

This was prepared following the procedure for Intermediate 2, replacing N- propylmaleimide with 5, 5-dimethyl-2-cyclopentene-1-one*, to provide the title compound as an oil.

Mass spec (electrospray) m/z calc for (C2rH32N203S + H) + : 393.

Found: (M+H) + : 393.

*Prepared by the method described in Tetrahedron (1993) 49,7931.

Intermediate 19 rel (1 S, 3R, 3aS, 6aR)-1-Isobutyl-2-(4-tert-butylbenzoyl)-3-(1,3-thiazol-2-yl) -octahydor-4- oxo-5, 5-dimethyl-cyclopenta [c] pyrrole-1-carboxylic acid, tertbutyl ester. This was prepared following the procedure for Intermediate 12, replacing Intermediate 7 with Intermediate 18. The compound was purified by chromatography on silica gel using cyclohexane-ethyl acetate (10: 1 then 4: 1, v/v) as eluent to provide the title compound as a solid.

Mass spec (electrospray) m/z calc for (C33H46N205S + H) + : 583.

Found: (M+H) + : 583.

Intermediate 20 2- [N- (5-methyl-thiazol-2-ylmethylene) amino]-4-methylpentanoic acid, tert-butyl ester

This was prepared following the procedure for Intermediate 1, replacing thiazole-2- carboxaldehyde with 5-methyl-thiazole-2-carboxaldehyde to provide the title compound.

'H NMR (CDCI3) : 8 8.33 (s, 1H), 7.56 (s, 1H), 4.01 (m, 1H), 2.49 (s, 3H), 1.75 (m, 2H), 1.52 (m, 1H), 1.45 (s, 9H), 0.93 (d, 3H) and 0.88 (d, 3H).

Intermediate 21 rel- (1 S, 3R, 3aS, 6aR)-1-Isobutyl-3-(5-methyl-1,3-thiazol-2-yl)-octahydro-4-ox o- cyclopenta [c] pyrrole-1-carboxylic acid, tert butyl ester.

This was prepared following the procedure for Intermediate 2, replacing N- propylmaleimide with cyclopentenone and Intermediate 1 with Intermediate 20 to provide the title compound.

Mass spec (electrospray) m/z calc for (C2oHgoN2O3S + H) + : 379.

Found: (M+H) + : 379.

Intermediate 22 rel-(1 S, 3R, 3aS, 6aR)-1-Isobutyl-2- (3-methoxy-4-tert-butylbenzoyl)-3- (5-methyl-1, 3- thiazol-2-yl)-octahydro-4-oxo-cyclopenta [c] pyrrole-1-carboxylic acid, tertbutyl ester. This was prepared following the procedure for Intermediate 12, replacing Intermediate 5 with Intermediate 21 to provide the title compound.

Mass spec (electrospray) m/z calc for (C32H44N205S + H) + : 569.

Found: (M+H) + : 569.

Example 1 rel-(1S, 3R, 3aS, 6aR)-1-Isobutyl-2-(4-tert-butylbenzoyl)-3-(1,3-thiazol-2-yl) -5-propyl- octahydro-4, 6-dioxo-pyrrolo [3, 4-c] pyrrole-1-carboxylic acid.

To a solution of Intermediate 7 (44 mg, 8. 85 mmol) in dichloromethane (5 mL) was added trifluoroacetic acid (1 mL) and the solution stirred at ambient temperature overnight. The reaction mixture was evaporated and the residue triturated with diethylether to give the title compound as a solid.

Mass spec (electrospray) m/z cale for (C28H35N205S + H) + : 526.

Found: (M+H) + 526 Example 2 rel-(1 S, 3R, 3aS, 6aR)-1-Isobutyl-2- (4-tert-butylbenzoyl)-3- (1, 3-thiazol-2-yl)-5-benzyl- octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid. This was prepared following the procedure for Example 1, replacing Intermediate 7 with Intermediate 8. The title compound was prepared as a solid.

Mass spec (electrospray) m/z calc for (C32H35N305S + H) + : 574.

Found: (M+H) + : 574 Example 3 rel-(1 S, 3R, 3aS, 6aR)-l-isobutyl-2- (4-tert-butylbenzoyl)-3- (1, 3-thiazol-2-yl)-5-methyl- octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid.

This was prepared following the procedure for Example 1, replacing Intermediate 7 with Intermediate 9. The title compound was prepared as a solid.

Mass spec (electrospray) m/z calc for (C26H31N305S + H) + : 498.

Found: (M+H) + : 498.

Example 4 rel- (1 S, 3R, 3aS, 6aR)-1-Isobutyl-2-(4-tert-butylbenzoyl)-3-(1,3-thiazol-2-yl) -octahydro-4- oxo-cyclopenta [c] pyrrole-1-carboxylic acid. This was prepared following the procedure for Example 1, replacing Intermediate 7 with Intermediate 10. The title compound was prepared as a solid.

Mass spec (electrospray) m/z calc for (C26H32N204S + H) + : 469.

Found: (M+H) + : 469.

Example 5 re/-(3aR, 4S, 6R, 6aS)-4-Isobutyl-5-(4-tert-butylbenzoyl)-6-(1,3-thiazol-2-yl) -hexahydro- furo [3,4-c] pyrrol-1-oxo-4-carboxylic acid.

This was prepared following the procedure for Example 1 replacing Intermediate 7 with Intermediate 11. The title compound was prepared as a solid.

Mass spec (electrospray) m/z calc for (C25H30N205S + H) + : 471.

Found: (M+H) + : 471.

Example 6 rel- (1 S, 3R, 3aS, 6aR)-1-Isobutyl-2- (3-methoxy-4-tert-butylbenzoyl)-3- (1, 3-thiazol-2-yl)- octahydro-4-oxo-cyclopenta [c] pyrrole-1-carboxylic acid.

This was prepared following the procedure for Example 1, replacing Intermediate 7 with Intermediate 12.

MS calcd for (C27H34N205S + H) + : 499.

MS found (electrospray) : (M+H)+ = 499.

Example 7 rel- (1 S, 3R, 3aS, 6aR)-1-Isobutyl-2-(3-bromo-4-tert-butylbenzoyl)-3-(1,3-thiaz ol-2-yl)-5- propyl-octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid. This was prepared following the procedure for Example 1, replacing Intermediate 7 with Intermediate 13.

MS calcd for (C28H34BrN305S + H) + : 604,606 MS found (electrospray) : (M+H) + = 604,606 Example 8 Enantiomer A of rel- (1S, 3R, 3aS, 6aR)-1-Isobutyl-2- (3-bromo-4-terf-butylbenzoyl)-3- (1, 3- thiazol-2-yl)-5-propyl-octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid.

F-I 0 NyO I z HOW S) Homochiral- single enantiomer of unknown absolute stereochemistry YBr Step A Intermediate 13 was resolved by preparative HPLC on a Chiralcel OD-H chromatography column using heptane-ethanol (80: 20, v/v) as eluent to afford the individual enantiomers with retention times of 5.9 minutes (Enantiomer A of rel- (1S, 3R, 3aS, 6aR)-1-Isobutyl-2-(3-bromo-4-tert-butylbenzoyl)-3-(1,3-thiaz ol-2-yl)-5- propyl-octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid, tert butyl ester) and 4.0 minutes (Enantiomer B) respectively. Enantiomer A was identical by'H NMR to Intermediate 13.

Step B Enantiomer A of re/ (1S, 3R, 3aS, 6aR)-1-Isobutyl-2-(3-bromo-4-tert-butylbenzoyl)-3-(1, 3- thiazol-2-yl)-5-propyl-octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid, tert butyl ester was deprotected following the procedure described for Example 1, replacing Intermediate 7 with Enantiomer A of Intermediate 13 to provide the title compound as a solid.

MS calcd for (C28H34BrN305S + H) + : 604,606.

MS found (electrospray) : (M+H)+ = 604,606.

Example 9 Enantiomer A of rel- (1S, 3R, 3aS, 6aR)-1-Isobutyl-2- (3-bromo-4-fert-butylbenzoyl)-3- (1, 3- pyridin-2-yl)-5-propyl-octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid. d . oSo r-I HO-I',, 1'N..." N Homochiral- single enantiomer of unknown absolute stereochemistry Br Step A Intermediate 16 was resolved by preparative HPLC on a Chiralpak AD chromatography column using heptane-isopropanol (60: 40, v/v) as eluent to afford the individual enantiomers with retention times of 4.9 minutes (Enantiomer A of rel-(1S, 3R, 3aS, 6aR)- <BR> <BR> 1-Isobutyl-2- (3-bromo-4-tert-butylbenzoyl)-3- (pyridin-2-yl)-5-propyl-octahydro-4, 6-dioxo- pyrrolo [3,4-c] pyrrole-1-carboxylic acid, tert butyl ester) and 9.4 minutes (Enantiomer B) respectively. Enantiomer A was identical by 1H NMR to intermediate 16.

Step B Enantiomer A of rel-(1S, 3R, 3aS, 6aR)-1-lsobutyl-2-(3-bromo-4-teff-butylbenzoyl)-3- (pyridin-2-yl)-5-propyl-octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid, tert butyl ester was deprotected following the procedure described for Example 1, replacing Intermediate 7 with Enantiomer A of Intermediate 16 to provide the title compound as a solid.

Mass spec (electrospray) m/z calc for (C3oH36BrN305+H) + : 598,600.

Found: (M+H) + : 598,600.

Example 10 Enantiomer A of rel-(1 S, 3R, 3aS, 6aR)-1-Isobutyl-2-(4-tert-butylbenzoyl)-3-(ppyridin-2-yl)- 5-propyl-octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid. r--, ,"Dz HOW N Homochiral- single enantiomer of unknown absolute stereochemistry Step A

Intermediate 17 was resolved by preparative HPLC on a Chiralpak AD chromatography column using heptane-isopropanol (70: 30, v/v) as eluent to afford the individual enantiomers with retention times of 10.24 minutes (Enantiomer A of rel- (1 S, 3R, 3aS, 6aR)-1-Isobutyl-2- (4-tert- butylbenzoyl)-3- (pyridin-2-yl)-5-propyl-octahydro- 4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid, tert butyl ester) and 6.82 minutes (Enantiomer B) respectively. Enantiomer A was identical by'H NMR to Intermediate 17.

Step B Enantiomer A of rel-(1S, 3R, 3aS, 6aR)-1-Isobutyl-2- (4-tert butylbenzoyl)-3- (pyridin-2-yl)- 5-propyl-octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid, tert butyl ester was deprotected following the procedure described for Example 1, replacing Intermediate 7 with Enantiomer A of Intermediate 17 to provide the title compound as a solid.

Mass spec (electrospray) m/z calc for (C30H37N305+H) + : 520.

Found: (M+H) + : 520.

Example 11 Enantiomer A of rel-(1S, 3R, 3aS, 6aR)-1-Isobutyl-2- (4-tert-butylbenzoyl)-3- (1, 3-thiazol-2- yl)-5-propyl-octahydro-4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid. NH horn zu -0 O =O Homochiral- single enantiomer of unknown absolute stereochemistry Step A Intermediate 7 was resolved by preparative HPLC on a Chiralcel OD chromatography column using heptane-isopropanol (85: 15, v/v) as eluent to afford the individual enantiomers with retention times of 11 minutes (Enantiomer A of rel-(1 S, 3R, 3aS, 6aR)-1- Isobutyl-2- (4-ter butylbenzoyl)-3- (thiazol-2-yl)-5-propyl-octahydro-4, 6-dioxo-pyrrolo [3, 4- c] pyrrole-1-carboxylic acid, test butyl ester) and 4.5 minutes (Enantiomer B) respectively.

Enantiomer A was identical by'H NMR to Intermediate 7.

Step B Enantiomer A of rel-(1S, 3R, 3aS, 6aR)-1-Isobutyl-2-(4-tert-butylbenzoyl)-3-(1,3-thiazol-2- yl)-5-propyl-octahydro4, 6-dioxo-pyrrolo [3,4-c] pyrrole-1-carboxylic acid, tert butyl ester was deprotected following the procedure described for Example 1, replacing

Intermediate 7 with Enantiomer A of Intermediate 7 to provide the title compound as a solid.

'H NMR (CDCI3) : 8 7.65 (d, 1H), 7.2 (m, 3H), 7.0 (d, 2H), 5.95 (d, 1H), 4.1 (t, 1H), 3.7 (d, 1H), 3.2 (t, 2H), 2.65 (dd, 1H), 2.4 (dd, 1H), 1.6 (m, 1H), 1.60 (s, 9H), 1.25 (s, 9H), 1.2 (m, 1H), 1.15 (2xd, 6H), 1.1 (m, 1H), 0.75 (t, 3H).

Example 12 re/-(1 S, 3R, 3aS, 6aR)-1-Isobutyl-2-(3-methoxy-4-tert-butylbenzoyl)-3-(1,3-thi azol-2-yl)- octahydro-4-oxo-5, 5-dimethyl-cyclopenta [c] pyrrole-1-carboxylic acid. This was prepared following the procedure for Example 1, replacing Intermediate 7 with Intermediate 19.

MS calcd for (C29H38N205S + H) + : 527.

MS found (electrospray) : (M+H) += 527.

Example 13 re/- (1S, 3R, 3aS, 6aR)-1-Isobutyl-2-(3-methoxy-4-tert-butylbenzoyl)-3-(5-methy l-1, 3- thiazol-2-yl)-octahydro-4-oxo-cyclopenta [c] pyrrole-1-carboxylic acid.

This was prepared following the procedure for Example 1, replacing Intermediate 7 with Intermediate 22.

MS calcd for (C28H36N205S + H) + : 513.

MS found (electrospray) : (M+H) + = 513.

The compounds according to the invention may be formulated for administration in any convenient way, and the invention therefore also includes within its scope pharmaceutical compositions for use in therapy, comprising a compound of formula (I) or a physiologically acceptable salt, solvate or enantiomer thereof in admixture with one or more physiologically acceptable diluents or carriers.

The compounds of the present invention can be administered by different routes including intravenous, intraperitoneal, subcutaneous, intramuscular, oral, topical, transdermal, or transmucosal administration. For systemic administration, oral administration is preferred. For oral administration, for example, the compounds can be formulated into conventional oral dosage forms such as capsules, tablets and liquid preparations such as syrups, elixirs and concentrated drops.

Alternatively, injection (parenteral administration) may be used, e. g. , intramuscular, intravenous, intraperitoneal, and subcutaneous. For injection, the compounds of the invention are formulated in liquid solutions, preferably, in physiologically compatible buffers or solutions, such as saline solution, Hank's solution, or Ringer's solution. In addition, the compounds may be formulated in solid form and redissolved or suspended immediately prior to use. Lyophilized forms can also be produced.

Systemic administration can also be by transmucosal or transdermal means. For transmucosal or transdermal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art, and include, for example, for transmucosal administration, bile salts and fusidic acid derivatives. In addition, detergents may be used to facilitate permeation. Transmucosal administration, for example, may be through nasal sprays, rectal suppositories, or vaginal suppositories.

For topical administration, the compounds of the invention can be formulated into ointments, salves, gels, or creams, as is generally known in the art.

The amounts of various compounds to be administered can be determined by standard procedures taking into account factors such as the compound (IC50) potency, (EC5o) efficacy, and the biological half-life (of the compound), the age, size and weight of the patient, and the disease or disorder associated with the patient. The importance of these and other factors to be considered are known to those of ordinary skill in the art.

Amounts administered also depend on the routes of administration and the degree of oral bioavailability. For example, for compounds with low oral bioavailability, relatively higher doses will have to be administered. Oral administration is a preferred method of administration of the present compounds.

Preferably the composition is in unit dosage form. For oral application, for example, a tablet, or capsule may be administered, for nasal application, a metered aerosol dose may be administered, for transdermal application, a topical formulation or patch may be administered and for transmucosal delivery, a buccal patch may be administered. In each case, dosing is such that the patient may administer a single dose.

Each dosage unit for oral administration contains suitably from 0.01 to 500 mg/Kg, and preferably from 0.1 to 50 mg/Kg, of a compound of Formula (I) or a pharmaceutical acceptable salt thereof, calculated as the free base. The daily dosage for parenteral, nasal, oral inhalation, transmucosal or transdermal routes contains suitably from 0.01 mg to 100 mg/Kg, of a compound of Formula (l). A topical formulation contains suitably 0.01 to 5.0% of a compound of Formula (I). The active ingredient may be administered from 1 to 6 times per day, preferably once, sufficient to exhibit the desired activity, as is readily apparent to one skilled in the art.

Composition of Formula (I) and their pharmaceutically acceptable salts which are active when given orally can be formulated as syrups, tablets, capsules and lozenges. A syrup formulation will generally consist of a suspension or solution of the compound or salt in a liquid carrier for example, ethanol, peanut oil. olive oil, glycerine or water with a flavoring or coloring agent. Where the composition is in the form of a tablet, any pharmaceutical carrier routinely used for preparing solid formulations may be used.

Examples of such carriers include magnesium stearate, terra alba, talc, gelatin, acacia, stearic acid, starch, lactose and sucrose. Where the composition is in the form of a capsule, any routine encapsulation is suitable, for example using the aforementioned carriers in a hard gelatin capsule shell. Where the composition is in the form of a soft gelatin shell capsule any pharmaceutical carrier routinely used for preparing dispersions or suspensions may be considered, for example aqueous gums, celluloses, silicates or oils, and are incorporated in a soft gelatin capsule shell.

Typical parenteral compositions consist of a solution or suspension of a compound or salt in a sterile aqueous or non-aqueous carrier optionally containing a parenterally acceptable oil, for example polyethylene glycol, polyvinylpyrrolidone, lecithin, arachis oil or sesame oil.

Typical compositions for inhalation are in the form of a solution, suspension or emulsion that may be administered as a dry powder or in the form of an aerosol using a conventional propellant such as dichlorodifluoromethane or trichlorofluoromethane.

A typical suppository formulation comprises a compound of Formula (I) or a pharmaceutically acceptable salt thereof which is active when administered in this way, with a binding and/or lubricating agent, for example polymeric glycols, gelatins, cocoa- butter or other low melting vegetable waxes or fats or their synthetic analogs.

Typical dermal and transdermal formulations comprise a conventional aqueous or non- aqueous vehicle, for example a cream, ointment, lotion or paste or are in the form of a medicated plaster, patch or membrane.

No unacceptable toxological effects are expected when compounds of the present invention are administered in accordance with the present invention.

ASSAY The potential for compounds of the invention to inhibit NS5B wildtyp HCV polymerase activity may be demonstrated, for example, using the following in vitro assay: In Vitro Detection of inhibitors of HCV RNA-dependent RNA Polymerase Activity Incorporation of [3H]-UMP into RNA was followed by absorption of the RNA polymer onto a DEAE glass fibre filter. A synthetic template consisting of 16mer oligoU hybridised to polyrA (10: 1 w/w) was used as a homopolymer substrate.

Reaction Conditions were 22 IlM [3H]-UTP (0.75 Ci/mmol), 1 mM-Dithiothreitol, 3.2 mM- MgCl2, 20 mM-Tris-HCI, pH7.0, 10 µg/mL polyA-oligoU, and 90 mM-NaCI. Note that 50mM-NaCI is added with the enzyme HCV RNA Polymerase (Recombinant full-length NS5B (Lohmann et al., J. Virol. 71 (11), 1997, 8416'Biochemical properties of hepatitis C virus NS5B RNA-dependent RNA polymerase and identification of amino acid sequence motifs essential for enzymatic activity') expressed in baculovirus and purified to homogeneity) was diluted to about 50 lug protein/mL (dependent on specific activity) in 50mM-Hepes, pH7.0, 0. 5M-NaCI, 20%- Glycerol, 0.05%-Triton X-100, 5mM-Dithiothreitol, 0. 1mM-EDTA.

5x Concentrated Buffer mix was prepared using 1 M-Tris-HCI (pH7.0, 1mL), 1M-MgCI2 (0. 16mL), 1 M-Dithiothreitol (0.05mL), 5M-NaCl (0.4mL), and Water (8.4mL), Total 10mL.

Substrate Mix was prepared using 5x Concentrated Buffer mix (12, uL), [3H]-UTP (1 µCi/µL ; 21. 7µM, 1µL), 22 µM-UTP (100 µM, 13. 2 uL), 10 ug/mL polyA-oligoU (100 pg/m L, 6gL), and Water (12. 8 µL), Total 45µL.

The Assay was set up using Substrate Mix (45µL), compound (10µL), and Diluted Enzyme (added last to start reaction) (5µL), Total 60µL.

The reaction was performed in a U-bottomed, clear, 96-well plate. The reaction was mixed on a plate-shaker, after addition of the Enzyme, and incubated for 2h at 22°C.

After this time, the reaction was stopped by addition of 251lL of 100mM-EDTA.

A DEAE Filtermat (Part No. 1205-405 from Pharmacia) was pre-washed in water and alcohol and dried. 2 x 20ttL of the Stopped Assay Mix was spotted onto a square of the DEAE Filtermat. The DEAE Filtermat was washed for 2x 15min in SSC buffer (0.3M- NaCI, 30mM-Na Citrate) followed by 2x 2min in water and 1x 1min in alcohol. The

Filtermat was dried and sealed in a bag together with 10mL of OptiScint HiSafe scintillation fluid. The radioactivity present on the filtermat was detected by scintillation counting on a Wallac 1205 Betaplate counter. After subtraction of background levels without enzyme, any reduction in the amount of radioactivity incorporated in the presence of a compound, compared to that in the absence, was taken as a measure of the level of inhibition. Ten concentrations of compounds were tested in two-or threefold dilutions. From the counts, percentage of inhibition at highest concentration tested or ICsos for the compounds were calculated using Grafit3 or Grafit4 software packages.

The exemplified compounds had an IC50 of <501lM. Accordingly, the compounds of the invention are of potential therapeutic benefit in the treatment and prophylaxis of HCV.

All publications, including but not limited to patents and patent applications cited in this specification are herein incorporated by reference as if each individual publication were specifically and individually indicated to be incorporated by reference as though fully set forth.