Abstract
2-cyanomethylbenzothiazole 1 reacts with acetone derivatives 2a-d, or acetonitrile derivative 6a-d in the presence of sulfur and triethylamine afforded the novel polysubstituted thiophene. Treatment of 1 with alkylidenemalononitrile derivatives IIa-h resulted in the formation of benzo[g]thiazo[3,2-a]pyridines in high yield.