Thrombin inhibitors. 3. Carboxyl-containing amide derivatives of N alpha-substituted L-arginine.

A series of N alpha-(arylsulfonyl)-L-arginine amide derivatives having carboxamide N-substituents with a carboxyl group was prepared and tested as inhibitors of the clotting activity of thrombin. The most inhibitory compounds were obtained when a carboxyl group was introduced into the carbon next to the amide nitrogen of N alpha-(arylsulfonyl)-L-arginine amide derivatives, e.g., N alpha-(arylsulfonyl)-L-arginyl-N-butyl-, N-(methoxyethyl)- or N-(tetrahydrofurfuryl)glycine and 4-alkyl-1-[N alpha-(arylsulfonyl)-L-arginyl]-2-piperidinecarboxylic acid, with an I50 of 1-3 X 10(-7) M.