For the syntesis of glycidyl methacrylate (GMA), the two-step method, which consists of the preparation of 3-chloro-2-oxypropyl methacrylate (MACE) by the reaction of epichlorohydrin (ECH) with methacrylic acid (MA) and the followed dehydrochlorination of MACE was investigated.
Among the tested catalysts, triethylbenzylammonium chloride (TEBAC) was most effective and other quarternary ammonium salts, which contain bulky groups, were less effective than TEBAC on the 1 st-step reaction. Tertiary amines, such as triethyl amine or pyridin, were effective catalysts, but they were also less effective than TEBAC.
Solvents showed no desirable effect on the 1st-step reaction.
The higher the reaction temperature, the more the acid conversion was, but the decrease in double bond was observed at 110°C.
The predominant reaction in the 1st-step was affected by the mixing method of reactants. The method dropping the ECH into MA was better than the method dropping the MA into ECH.
The yield of distillated MACE was 92.3%.
The dehydrochlorination of MACE, the 2nd-step, was investigated by means of “epoxides interchange method”. By using phenyl glycidyl ether as a dehydrochlorinating agent and TEBAC as a catalyst, GMA was obtained in about 74% yield. Without TEBAC the yield decreased to 55%.
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