Synthesis of 4-Aldehydebenzofurazan

4-Aldehydebenzofurazan was synthesized from 4-methylbenzofurazan via bromination and Sommelet reaction.The effects of the brominating agent and the initiator on the bromination and the reactants ratio,the temperature and the reaction time on the Sommelet reaction were investigated.The optimal reaction conditions for the first step were as follows: bromosuccinimide as brominating agent,benzoyl peroxide as the initiator,62℃ for 5 h,and for the second step were as follows: the molar ratio of 4-(bromomethyl)benzofurazan to hexamethylenetetramine of 1 to 1.2,acetic acid as the catalyst and the solvent,the salt-forming reaction at 60℃ for 2 h,the acidolysis reaction at 80 ℃ for 4 h.The final product was obtained in overall yield of 68%.