Hepatitis C inhibitor tri-peptides

A racemate, diastereoisomer or optical isomer of a compound of formula (I):

• wherein B is H, a C6 or C10 aryl, C7-16 aralkyl;
• Het or (lower alkyl)-Het, all of which optionally substituted with C1-6 alkyl;
• C1-6 alkoxy;
• C1-6 alkanoyl;
• hydroxy;
• hydroxyalkyl;
• halo;
• haloalkyl;
• nitro;
• cyano;
• cyanoalkyl;
• amino optionally substituted with C1-6 alkyl;
• amido;
• or (lower alkyl)amide;
• or B is an acyl derivative of formula R4—C(O)—;
• a carboxyl derivative of formula R4—O—C(O)—;
• an amide derivative of formula R4—N(R5)—C(O)—;
• a thioamide derivative of formula R4—N(R5)—C(S)—;
• or a sulfonyl derivative of formula R4—SO2 wherein
• R4 is (i) C1-10 alkyl optionally substituted with carboxyl, C1-6 alkanoyl, hydroxy, C1-6 alkoxy, amino optionally mono- or di-substituted with C1-6 alkyl, amido, or (lower alkyl) amide;
• (ii) C3-7 cycloalkyl, C3-7 cycloalkoxy, or C4-10 alkylcycloalkyl, all optionally substituted with hydroxy, carboxyl, (C1-6 alkoxy)carbonyl, amino optionally mono- or di-substituted with C1-6 alkyl, amido, or (lower alkyl) amide;
• (iii) amino optionally mono- or di-substituted with C1-6 alkyl;
• amido;
• or (lower alkyl)amide;
• (iv) C6 or C10 aryl or C7-16 aralkyl, all optionally substituted with C1-6 alkyl, hydroxy, amido, (lower alkyl)amide, or amino optionally mono- or di-substituted with C1-6 alkyl;
• or
• (v) Het or (lower alkyl)-Het, both optionally substituted with C1-6 alkyl, hydroxy, amido, (lower alkyl) amide, or amino optionally mono- or di-substituted with C1-6 alkyl;
• R5 is H or C1-6 alkyl;
• with the proviso that when B is a carboxyl derivative, an amide derivative or a thioamide derivative, R4 is not a cycloalkoxy;
• Y is H or C1-6 alkyl;
• R3 is Cl4 alkyl, C3-7 cycloalkyl, or C4-10 alkylcycloalkyl, all optionally substituted with hydroxy, C1-6 alkoxy, C1-6 thioalkyl, amido, (lower alkyl)amido, C6 or C10 aryl, or C7-16 aralkyl;
• R2 is CH2—R20, NH—R20, O—R20 or S—R20, wherein R20 is pyridinyl, quinolyl, (lower alkyl)-pyridinyl or (lower alkyl)-quinolyl, each optionally mono-, di- or tri-substituted with R21,
• wherein each R21 is independently C1-6 alkyl;
• C1-6 alkoxy;
• lower thioalkyl;
• sulfonyl;
• NO2;
• OH;
• SH;
• halo;
• haloalkyl;
• amino optionally mono- or di-substituted with C16 alkyl, C6 or C10 aryl, C7-14 aralkyl, Het or (lower alkyl)-Het;
• amido optionally mono-substituted with C1-6 alkyl, C6 or C1-10 aryl, C7-14 aralkyl, Het or (lower alkyl)-Het;
• carboxyl;
• carboxy(lower alkyl);
• C6 or C10 aryl, C7-14 aralkyl or Het, said aryl, aralkyl or Het being optionally substituted with R22;
• wherein R22 is C1-6 alkyl;
• C3-7 cycloalkyl;
• C1-6 alkoxy;
• amino optionally mono- or di-substituted with C1-6 alkyl;
• sulfonyl;
• (lower alkyl)sulfonyl;
• NO2;
• OH;
• SH;
• halo;
• haloalkyl;
• carboxyl;
• amide;
• (lower alkyl)amide;
• or Het optionally substituted with C1-6 alkyl;
• R1 is H;
• C1-6 alkyl, C3-7 cycloalkyl, C2-6 alkenyl, or C2-6 alkynyl, all optionally substituted with halogen;
• or a pharmaceutically acceptable salt or ester thereof;
• wherein “Het” is defined as a five-membered saturated or unsaturated, aromatic or non-aromatic, heterocycle containing from one to four heteroatoms selected from nitrogen, oxygen and sulfur, wherein said heterocycle is optionally fused to a benzene ring.