Synthesis of 2‐Amino Benzothiophenes Through C–S Bond Formation

ABSTRACT A widely applicable synthesis of medicinal chemistry‐relevant 2‐aminobenzo[ b ]thiophenes has been achieved from ortho ‐halo‐substituted thioamides of 2‐arylacetic acids through a t ‐BuOK‐promoted intramolecular C–S bond formation under transition‐metal‐free conditions. The operationally simple, high‐yielding protocol is based on readily accessible substrates and tolerates a variety of functional groups. Density functional theory (DFT) studies, along with mechanistic investigations, including EPR spin trapping experiments, were conducted to elucidate a plausible reaction mechanism.