微波辐射合成草酸二苄酯

在微波辐射条件下,以草酸、氢氧化钾和溴化苄为原料,四丁基溴化铵为相转移催化剂,聚乙二醇200为溶剂合成了草酸二苄酯,并通过熔点和红外光谱对产物的结构进行了表征。研究了反应物配比、相转移催化剂用量、微波辐射功率、辐射时间等对产物收率的影响。实验结果表明,当n(草酸):n(氢氧化钾):n(溴化苄)=1:2.83:2．34、四丁基溴化铵用量0．15 g、聚乙二醇200用量10 mL、微波功率160 W、辐射时间4．5 min时,草酸二苄酯的收率可达62．96％。

SYNTHSIS OF DIBENZYL OXALATE UNDER MICROWAVE IRRADIATION

Dibenzyl oxalate was synthesized from oxalic acid, potassium hydroxide and benzyl bromide under microwave irradiation using tetrabutylammonium bromide as phase-transfer catalyst and polyethylene glycol-200 as solvent. Structures of the products were identified by means of melting point measurement and IR. By a single factor test, effects of the reactant ratios, phase-transfer catalyst, microwave power and irradiation time, etc. , on the reaction were studied. Under the optimal reaction conditions, i. e. , n(oxalic acid) : n(potassium hydroxide) :n(benzyl bromide) = 1 : 2. 83 : 2. 34, tetrabutylammonium bromide 0. 15 g, polyethylene glycol-200 10 mL, microwave power 160 W and irradiation time 4. 5 min, the yield of dimonbenzyl oxalate reached 62. 96%.