Vilsmeier-Haak formylation of 2,2'-bithenyl

Abstract

The Vilsmeier-Haak formylation of 2,2?-bithenyl, using the complex prepared from phosphorus oxychloride and dimethylformamide, has been shown to give 5,5?-diformyl-2,2?-bithenyl and 1-[5-(5-formyl-2- thenyl)methyl-2-thienyl]-2,3-di(5-formyl-2-thienyl)propene. Two minor products, 5-formyl-2,2?-bithenyl and 1-(5-formyl-2-thienyl)-2-(2- thienyl)ethylene were isolated as the corresponding 2,4- dinitrophenylhydrazones. The structures of the formylation products were established by analysis, and by infrared and ultraviolet spectroscopy.