Synthesis and anticonvulsant activity of new 3'-aryl- 7-bromo-spiro[ [1]benzothiophene-3,2'-[1,3] thiazolidine]-2,4'-dione derivatives

Two series of spiro[ [1]benzothiophene-3,2'-[1,3]thiazolidine]-2,4'-diones 5a-e and 6a-e were synthesized, characterized and evaluated for anticonvulsant activity. Reaction of [1]benzothiophene-2,3-dione (3) with certain arylamines afforded the corresponding Schiff bases 4a-e. Cyclization of 4a-e with thioglycolic or thiolactic acids brought about the target spiro compounds 5a-e and 6a-e respectively. Spectral data, IR and 1H-NMR proved that the structure of the spiro compounds 5a-e and 6a-e might be in a mixture of two forms or derivatives of [1,3]thiazolidinone and / or hydroxy[1,3]thiazole. The final compounds were tested for their anticonvulsant activity.