Intramolecular Cyclization of Amido Acids into Pyrrolidinothieno(or [1]benzothieno)[3]azepinediones

Article abstract of DOI:10.1002/jhet.5570340134

The synthesis of pyrrolidino[2,1-b]thieno[3,2(2,3)-f[3]azepinediones 7a,b and pyrrolidino[2,1-b]-[11]benzothieno[3,2(2,3)-f][3]azepinediones 7c,d are described starting from thiophenes or [1]benzothiophenes acetic acids. Their selective reduction using triethylsilane led to the corresponding azepinones 17a-d.