2-Bromo-i-phenylethylidenemalononitrile in the synthesis of thieno[3,2-b]pyridines and thiazolo[4,5-b]pyridines

A novel regioselective synthesis of thieno[3, 2-blpyridines and thiazolo[4,5-blpyridines from 2-bromo-I-phenyl ethylidenemalononitrile is proposed. In the case of the thiazolo[4, 5-b]pyridines, the intermediate 5-(2, 2-dicyano-l-phenylvinyl)thiazoles were separated. Formation of the thiazolo(4,5-b]pyridines was confirmed by x-ray analysis.A. D. Zelinski Institute of Organic Synthesis, Russian Academy of Sciences, Moscow 117913. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 413–419, March, 1996. Original article submitted December 22, 1995.