The Synthesis Of Methylene Benzoyl

At present, there are many reports about methylene benzoyl synthetic methods, butmost of the raw materials are difficult to obtain or the price is higher. Through theunderstanding of the various synthesis methods, and then improving process method,high quality methylene benzoyl synthesis is getted.This topic, with acetophenone respectively and methyl benzoic acid as rawmaterials, and with acetophenone and benzoic acid ethyl ester as a raw material, underthe action of catalyst, made methylene benzoyl through claisen condensation reactions.With the combination of single factor experiment and orthogonal experiment method,the study carries out a detailed investigation of the raw material atio, catalyst dosage,reaction temperature and reaction time, which influences on the yield of DBM. Themore suitable catalyst and optimizing process conditions were determined.Main conclusions are as follows:(1)The optimization process of DBM,with methyl benzoic acid as rawmaterial:sodium methoxide as catalysts, xylene as solvent selection, n (acetophenone): n(sodium methoxide): n (xylene): n (methyl benzoate)=1:1.6:10:4, reaction temperatureis140-150℃, the reaction time of5h. The yield of product was90%.(2) The optimization process of DBM, with benzoic acid ethyl ester as a raw material:sodium ethoxide as catalyst, n (acetophenone): n (sodium ethoxide)=1:1.0, n (ethylbenzoate): n (acetophenone)=6:1, reaction temperature is150-160℃, reaction time is4h. The reaction yield was81%.The purity of the product can be calculated by the iodide method; The melting point ofproduct is tested by microscopic melting point instrument; Product was analyzed byinfrared spectrum and nuclear magnetic resonance hydrogen characterization methods, andthe product structure is confirmed.