Synthesis of new bioactive benzothiophene derivatives

ABSTRACT

Synthesis of new Schiff bases [II] of expected biological activity by reacting 5-nitrobenzo [b] thiophene-2-carboxyaldehyde [I] with different amines and hydrazine hydrate is described. Cyclocondensation of the resulted Schiff bases with thioglycolic acid affords thiazolidin-4-one derivatives [III]. Schiff bases with ortho OH, NH2 or SH substituent in the N-aryl ring, when treated with lead tetra- acetate and/or N-bromosuccinimide, give the cyclization products [IV]. Also when the carboxyaldehyde [I] condensed with different hydrazines, the corresponding hydrazones [V] were obtained. The synthesized compounds showed significant anti-microbial activities