S-Alkylation of 1-Aryl-7,8-dimethoxy-3,5-dihydro-4H-2,3-benzodiazepine-4-thiones

Abstract

A series of new N-aryl-2-[(1-aryl-7,8-dimethoxy-5H-2,3-benzodiazepin-4-yl)sulfanyl]acetamides were synthesized by the S-alkylation of 1-aryl-7,8-dimethoxy-3,5-dihydro-4H-2,3-benzodiazepine-4-thiones with N-aryl-2-chloroacetamides. The reaction of 2,3-benzodiazepine-4-thiones with chloroacetic acid in the presence of bases afforded the corresponding 1-aryl-7,8-dimethoxy-3,5-dihydro-4H-2,3-benzodiazepin-4-ones in high yields instead of the expected alkylation products. The two-dimensional ¹H–¹³C NMR spectra (HSQC, HMBC) of 2-{[1-(4-bromophenyl)-7,8-dimethoxy-5H-2,3-benzodiazepin-4-yl]sulfanyl}-N-phenylacetamide were analyzed.