Reactions of some new thienothiophene derivatives

Facile and convenient syntheses of bisdimethylthieno2,3-b]thiophen-2,5-diyl bis(oxazole-2-amine), bis(1H-imidazol-2-amine), bis((3a)-H-indole),1,2-a]pyrimidine), bis(1H-imidazo1,2-b]1,2,4]triazole) and bis(9H-benzod]imidazo1,2-a]imidazole) derivatives incorporating a thieno2,3-b]thiophene moiety from the versatile and readily accessible 1,1'(3,4-dimethylthieno2,3-b]thiophene-2,5-diyl)-bis(2-bromo-ethanone) (1) are described.