Amino acid thrombin inhibitors

Disclosed are compounds of the formula (I); wherein, p and q independently represent 0; R1 represents H; R2 represents H; R3 represents phenyl (which group is substituted by one or more of C1-4 alkyl, C1-4 alkoxy, Halo, hydroxy, cyano, nitro, methylenedioxy, trifluoromethyl, N(H)R27 or C(O)OR28; R27 represents H, C1-4 alkyl or C(O)R29; R28 and R29 independently represent H or C1-4 alkyl; R4 represents H or C1-4 alkyl; Y represents C1-3 alkylene optionally substituted by C1-4 alkyl, hydroxy, methylene or oxo; n represents 1; and B represents a structural fragment of formula IVa R5 represents H, halo or C1-4 alkyl; or a pharmaceutically acceptable salt thereof. Further disclosed is the use of compounds of the formula (I) in the preparation of a medicament for the treatment of a condition where the inhibition of thrombin is required; such as, use as an anticoagulant or, the treatment of thrombosis. (62) Divided out of 504312