SYNTHESIS AND APPLICATION OF 4-(COUMARIN-3-YL)-THIOPHENES

Abstract
A facile synthesis of 4-(coumarin-3-yl)thiophenes (6a-6j) was achieved by the condensation of ethyl 2-acetamido-3, 5-dicarbethoxythiophene-4 acetate (4) with selected o-hydroxyaldehydes (5a-5j) in the presence of piperidine. The key intermediate, ethyl 2-acetamido-3, 5-dicarbethoxythiophene-4-acetate (4) was synthesized by cyclocondensation of diethyl acetonedicarboxylate (1), sulfur and ethyl cyanoacetate (2) by a Gewald synthesis followed by acetylation. 4-(Coumarin-3-yl)thiophenes (6a-6j) were applied on polyester fibers as fluorescent disperse dyes and their fluorescence and dyeing properties were studied.