Substituted 4H-3.1-benzoxazin4-ones are potential intermediates in the synthesis of 2, 3- disubstituted4-(3H) quinazolinones, pharmaceutical agents2 and linking-units in thermally stable polymers? A wide variety of procedures leading to benzoxazin4-ones are available in literature. The most common approach consists of the reaction of N-acylanthranilic acid with acetic anhydridela or treatment of anthranilic acid with carboxylic acid chlorides! In recent ...