Method for the preparation of pyrido benzoxazine derivatives

摘要

There is disclosed a method for the preparation of pyrido benzoxazine derivative having the following formula I, that is improved in both production coat and yield. The method comprises reacting a compound of the following general formula II with tetraalkyl ammonium fluoride or with a mixture of tetraalkyl ammonium halide and metal fluoride in an organic solvent at a reaction temperature of about 30 to about 100 DEG C. for 1 to 3 hours under stirring; and reacting the resulting solution with a metal hydroxide or a metal carboxylate dissolved in water or in a mixture of water and alcohol, for 1 to 3 hours under heat. wherein X is a fluorine or chlorine atom and X1 and X2 each is a halogen atom or a nitro group, R is an alkyl group containing 1 to 4 carbon atoms and R1, R2, R3 and R4 each is an alkyd group or allyl group containing 1 to 8 carbon atoms.