citric acid as an efficient and green catalyst for the synthesis of hexabenzylhexaazaisowurtzitane (hbiw)

the condensation of benzylamine with glyoxal leads to hexabenzylhexaazaisowurtzitane (hbiw) in acetonitrile solvent with citric acid as a green catalyst under both conventional stirring and ultrasonic irradiation conditions. the influence of four variables, including the amount of catalyst, solvent, reaction time and ultrasonic power, on the reaction yield was investigated. the results showed that the optimum parameters for synthesis of hbiw were 5% mol with respect to glyoxal for catalyst, acetonitrile-water as solvent, 5 minutes as reaction time and 150 w for ultrasonic power. in general, improvement in rates and yields were observed when the reactions were carried out under sonication in comparison with classic conditions.