Synthesis and some transformations of thioesters of thienylacrylic acid
A number of thioesters of thienylacrylic acid were obtained by the condensation of 2-formylthiophene and 5-bromo-2-formylthiophene with acetylenic thioethers in the presence of boron trifluoride etherate. The reaction of the condensation products with hydrazine hydrate is accompanied by intramolecular cyclization to form the corresponding pyrazolines. The IR spectra of the synthesized compounds are discussed.