The chemistry of isatoic anhydride derivatives: electrophilic reactions of 2-amino-3,1-benzoxazin-4-one

Abstract

2-Amino-3,1-benzoxazin-4-one (‘iminoisatoic anhydride’) reacts with nucleophiles to yield 2-substituted phenylurea derivatives which undergo cyclisation to give a number of new quinazolone derivatives. With ethyl cyanoacetate, diethyl malonate, malononitrile, and acetoacetonitrile the corresponding quinazolones (6)–(9) are obtained. Sodium cyanamide yields the 3-N-cyano-derivative (21).