Oxidative cyclocondensation of thio(seleno)-amides and ureas 1. 2-thioxo-4-quinazolone

Article abstract of DOI:10.1007/BF01164875

It has been found for the first time that 2-thioxo-4-quinazolone in the presence of acid catalysts in dimethyl sulfoxide is converted to 8H,15H-1,2,4-thiadiazolo[3, 2-b:5, 4-b′]diquinazoline-8, 15-dione. The reaction proceeds via oxidative cyclocondensation. The formation of this structure in preference to five other proposed isomers is substantiated using quantum-chemical methods. 1997 Plenum Publishing Corporation.