Synthesis of nitriles, esters, amides of the substituted 2-amino-1-(4,5,6,7-tetra-hydrobenzo[ b ]thiophen-2-yl)-4-oxo-5-(2-oxo-2-arylethylidene)-4,5-dihydro-1H-pyrrole-3-carboxylic acids bearing the nitrile group at the thiophene ring by the reaction of the substituted 3-(3-cyanothiophen-2-yl)iminofuran-2(3H)-ones with the appropriate cyanoacetic acid derivatives was developed. The synthesized compounds demonstrated pronounced antinociceptive activity and low toxicity (toxicity class V of practically nontoxic substances).