Synthesis of thieno[2,3-b]azepin-4-ones as potential antineoplastic agents

In view of the antitumor activity reported for 7,8-dimethylbenzo[b]azepine-2,5-dione, new isosteric thieno[2,3-b]-azepin-4-ones have been prepared by a Dieckmann ring closure reaction. Substituted 2-amino-3-carbethoxythiophenes were tosylated, or benzoylated, and the corresponding sodium salt was alkylated with ethyl 4-bromobutyrate. The resulting product was cyclized in the presence of sodium hydride, and the azepinones were detosylated with 40% sulfuric acid-acetic acid solution. Preliminary biological data do not indicate any siginificant antineoplastic activity.