Synthesis and behaviour of a static benzoxazinone derivative towards nitrogen and sulphur nucleophieles

4 [H]-3,l-BENZOXAZIN-4-one derivatives bear saturated aliphatic substituents at position-2, [so called dynamic benzoxazinones], e.g., CH[3][1] C[3]H[7] [iso] [2], CH[2]COCH[3][3], CH2CN[4], C[3]H[7][n] and CH[2]CH[2]COOH[5] are among the more recent heterocyclic compounds. The electronically unsaturated character of these rings made difficult the synthesis of satisfactorily stable rings. New organic substituents with special properties in steric and in an electronic manner-helped to solve this problem. In the last two decades, our contribution to the solution of this problem includes the use of bulk substituents involving strong conjugation power [which so called static benzoxazinones[6-12]. In continuation of our recent article [1,3], on the behaviour of a static benzoxazinone derivative towards nitrogen and carbon nucleophiles, another derivative namely 2-[2-[4-bromohydroxyimmobenzyl] phenyl]-4[H]-3,l-benzoxazin-4-one [3] was obtained via the interaction of 1 - [4-bromophenyl] -4[H] -3,2 -benzoxazin-4-one [2] with anthranilic acid in boiling n-butanol in which hetero-ring opening takes place followed by cyclisation