Synthesis of benzothiophenes

Abstract

Abstract Four methylbenzothiophenes and two methylnaphthothiophenes were synthesized by cyclization of arylketosulphides (obtained by reaction of α‐halogen ketones on thiophenols) in the presence of zinc chloride or phosphorus pentoxide. U.V. absorption spectra of the benzo and naphthothiophenes and their dioxides were measured to be used for the identification of benzothiophenes in mixtures with other compounds.