Access to Dihydroquinazolinones, spiro-Quinazolinones and their Bioactive Molecular Scaffolds by Exploring the Unique Reactivity of 2-Nitrobenzonitrile towards Cu-Hydrazine Hydrate

摘要

A unique reactivity of 2-nitrobenzonitrile towards hydrazine hydrate has been demonstrated, which was explored for the rapid and efficient synthesis of dihydro-quinazolinone derivatives. In this reaction, hydrolysis of nitriles followed by reduction of the nitro group was observed only for the ortho-isomer. The reaction sequences involve a concerted pathway for the formation of 2-aminobenzamide from 2-nitrobenzoni- trile, where copper catalyzed both the hydrolysis of the cyano group as well as the reduction of the nitro group simultaneously. This methodology has been used to synthesize a variety of electronically varied spiro- and dihydro quinazoli-nones with high yield and functional group tolerance. In addition, the methodology has also been applied to the synthesis of biologically potent molecular entities.