| abstract |
The present invention relates to a novel selective thrombin inhibitor having the following formula (I), which is also effective by oral administration: in which R1 represents acetyl substituted with aryl or aryloxy, or represents sulfonyl substituted with substituted or unsubstituted aryl or N-containing heterocyclic group, X represents a group of formula R2 and R3 independently of one another represent hydrogen; cycloalkyl substituted or unsubstituted with carboxyl or alkoxycarbonyl; arylalkyloxy; hydroxy; or lower alkyl substituted or unsubstituted with carboxyl, alkoxycarbonyl or hydroxy, or R2 and R3 together with nitrogen atom to which they are attached can form a piperidine group substituted with carboxyl or alkoxycarbonyl, R4 represents hydrogen, lower alkyl or lower alkoxy, R5 represents alkanesulfonyl; alkoxycarbonyl; alkylcarbonyl; formyl; lower alkyl; aryl substituted or unsubstituted with alkoxy or haloalkyl; or hydroxy-substituted lower alkyl, and R6 and R7 independently of one another represent hydrogen, lower alkyl or amino, and to a process for preparation thereof and a pharmaceutical composition for thrombin inhibition which comprises the compound of formula (I) as an active ingredient. |