SYNTHESIS OF NOVEL THIENOPYRIMIDINES AND THIENODIAZEPINES FROM ETHYL 2,4-DIAMINO-5-{[(2E)-2- (1-PHENYLETHYLIDENE)HYDRAZINO]CARBONYL}THIOPHENE-3- CARBOXYLATE

Abstract

Ethyl 2,4-diamino-5-{[(2E)-2-(1-phenylethylidene)hydrazino]- carbonyl}thiophene-3-carboxylate (3) was synthesized via Gewald reaction that can be readily used as precursor to potentially interesting thiophenes. Compound 3 reacted with cyanoacetamide and/or malononitrile producing thienopyrimidines 4 and 5, respectively. Reaction of compound 3 with hydrazinecarbodithioic acid afforded pyrimidothienotriazepine 6. Treatment of compound 3 with ethylenediamine and carbon disulfide gave (imidazolinyl)thiophene 7. The latter compound can be used as building blocks for the synthesis of various heterocycles. Structures of the newly synthesized compounds were deduced based on their analytical and spectral data.