Synthesis and reactions of benzo[b]thieno[2,3-c]pyrylium pairs

Benzob]thieno2,3-c]pyrylium perchlorates were obtained in high yields in the acylation of benzob]thien-3-ylacetone with aliphatic acid anhydrides in the presence of 70% perchloric acid. Treatment of the products with ammonia converts them to benzob]thieno2,3-c]pyridines (in yields higher than 90%), whereas hydroxy and dialkylamino derivatives of dibenzothiophene were obtained in up to 50% yields by treatment of the products with alkalis or secondary amines, respectively.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1351–1354, October, 1981.