Sodium Dithionite Mediated One-Pot, Tandem Reductive Cyclization of 2-(2-nitrophenyl)quinazolin-4(3H)-one with Diverse Aldehydes and Glyoxals

A one-pot, metal-free tandem reductive cyclization of 2-(2-nitrophenyl)quinazolin-4(3H)-one with broad range of structurally diverse aldehydes and glyoxals has been developed using sodium dithionite (Na₂S₂O₄) as a cost-effective and environmentally benign reducing agent. The protocol employs green solvents such as ethanol and water, avoiding formation of metal salt by-products thereby simplifying the workup procedures and enabling the isolation of product by simple filtration. Furthermore, ESI-HRMS and DFT studies were conducted for the identification of the key intermediates and to elucidate the proposed reaction mechanism.

Publication History

Received: 23 May 2025

Accepted after revision: 15 July 2025

Accepted Manuscript online:
15 July 2025