Synthesis and reactions of 2-chloromethyl-3,1-benzoxazin 4-ones with amines

ABSTRACT

In continuation of our previous works on the reaction of 3,1 - benzoxazin -4 - ones with amines [1,4], it has been found interesting to synthesize 6 - bromo and 6,8 - dibromo - 2 - chloro - methyl - 3, 1 - benzoxazin - 4 - ones IIa, b and to then study their reactions with a variety of amines. Accordingly, 5-bromo and 3,5-dibromoanthranilic acids were chloroacetylated to give I which were cyclodehydrated to the corresponding benzoxazinones IIa, b. Reaction of IIa, b with aromatic amines, ammonia and/or hydrazine hydrate in ethanol or dioxane produced the 2- chloromethyl -4-quinazolinones IIIa-p, presumably through the attack of the amines on the electrophilic C-2 of the benzoxazinone ring system, regardless the amount of the amine used. Structures of III were confirmed by microanalytical and spectroscopic data [table 1]. Evidence was investigated by conversion of III to the corresponding salicylate esters IV via their reaction with sodium salicylate