Synthesis and Antinociceptive Activity of N-Substituted 4-Aryl-4-oxo-2-[(3-thiophen-2-yl)amino]but-2-enamides

2-{[5-Aryl-2-oxofuran-3(2H)-ylidene]amino}thiophene-3-carboxylic acid derivatives reacted with substituted amines to give new N-substituted 4-aryl-4-oxo-2-[(3-thiophen-2-yl)amino]but-2-enamides. Antinociceptive activity of the synthesized compounds was studied.