SYNTHESIS OF BENZO[2,1-b:3,4-b']DITHIOPHENE-4,5-DIONE DERIVATIVES

摘要

The 1-trimethylsilylimidazole-mediated thiophene ring formation from 6-acylbenzo[b]thiophene-4,5-diones (3),which were prepared utilizing photoacylation of benzo[b]thiophene-4,5-dione (1) with aliphatic aldehydes,and ethyl mercaptoacetate,followed by acid hydrolysis and oxidation with cerium(IV) ammonium nitrate (CAN),led to one-pot formation of the 3-substituted ethyl 4,5-dioxo-4,5-dihydrobenzo[2,1-b:3,4-b']dithiophene-2-carboxylates (4) in satisfactory yields.