There are very few synthetic routes for the synthesis of N-substituted-1,2-dihydro-(4H)-3,1-benzoxazin-4-ones and 1-substituted-1,2-dihydro-(4H)-quinazoline-4-ones [1,2]. They are good potential starting materials for synthesis of pharmaceutical and biological important heterocycles [3,4]. The Schiff-bases produced from the condensation reaction of aryl aldehydes with anthranilic acid or anthranilamide, are cyclized with benzenesulfonyl chloride to produce the 1,2-dihydro-(4H)-3,1-benzoxazin-4-ones2and 1,2-dihydro-(4H)- quinazoline-4-ones 4respectively in PEG as a green solvent (Scheme 1). Good to high yield of the products are obtained under mild reactions conditions with simple work-up.
