Selective Synthesis of Bromo-substituted Naphthalene Dianhydride Derivatives

In recent years,core-substituted 1,4,5,8-naphthalene diimides(cNDIs) have been widely used in numerous research fields,such as materials and supramolecular chemistry.As the important precursors for the synthesis of cNDIs,2-bromo and 2,6-dibromo-1,4,5,8-naphthalene dianhydride derivatives are difficult to separate from each other,but their mixture is easily obtained according to the most synthesis conditions which have been reported.In order to develop an efficient,practical method to obtain 2-bromo and 2,6-dibromo-1,4,5,8-naphthalene dianhydride derivatives respectively,the reaction were performed with NaBr and oleum as the bromide reagents under atmospheric pressure,and the effects of reaction time,temperature,SO3 content in oleum and NaBr quantity were investigated.2-Bromo and 2,6-dibromo-1,4,5,8-naphthalene dianhydride derivatives were selectively synthesized.Their structures and yields were characterized by derivatization of them for their napnthalimide compounds.