Synthesis of tert-butyl-methoxy-dibenzoylmethane under microwave irradiation

Ultraviolet absorbent 4-tert-butyl-4'-methoxy-dibenzoylmethane was synthesized starting from tert-butyl toluene as raw material by a process under microwave irradiation covering oxidation,esterification and Claisen condensation.Experiment based upon orthogonal design with four factor and two levels,were carried out for optimization of conditions for the esterification.Conditions influencing the result of Claisen condensation were investigated by single factor tests.Experimental results showed the suitable conditions are as follows:using toluene as the solvent and sodium amide as the catalyst for carrying out the Claisen condensation.Molar ratio n(p-methoxy acetophenone)∶n(methyl p-tert-butyl benzoate)∶n(sodium amide)=1∶2∶4.Time needed for microwave irradiation is 60 min.Power of microwave is 320 W.The yield can achieve 70.22%.The product were characterized by 1HNMR and UV spectra.