Williamson反应合成二乙二醇二甲醚及其合成条件优化

Synthesis of diethylene glycol dimethyl ether over williamson reaction and Optimization of Its Synthetic Conditions

以二乙二醇单甲醚(C5H12O3)和氯甲烷为原料,氢氧化钠为催化剂,在n(NaOH):n(C5H12O3)=1.4∶1.0(mol/mol),减压条件下,先合成二乙二醇单甲醚醇钠盐,然后通入CH3Cl与二乙二醇单甲醚钠盐进行Williamson反应合成二乙二醇二甲醚(DMDE)。用正交实验法对二乙二醇二甲醚的合成条件进行了优化,气相色谱法分析了产品中DMDE的含量,用FT-IR和NMR分析测试手段表征了产物结构。实验结果表明该反应的最优工艺条件为:n(NaOH)/n(C5H12O3)/n(CH3Cl)=1.4∶1.0∶1.4,反应温度为90℃,CH3Cl通入时间为4.0h,二乙二醇二甲醚的收率可达95.0%以上。

Based on die thylene glycol mono- methyl ether（ C5 H12O3 ）and CH3Cl as raw materials, hydrate of -sodium as catalyst, Diethylene glycol mono- methyl ether monosodium salt was synthesized from under vacuum pressure condition, n（ NaOH）/n （C5H12O3 ） = 1.4： 1. 0. Then diethylene glycol dimethyl ether（DMDE） was synthesized through Williamson reaction from CH3 Cland CH3OCH2CH2OCH2CH2ONa. Its synthetic condition was was optimized by orthogonal experiment. The purity of DMDE was analyzed by gas chromatography, Its structure was characterized by FT- IR and NMR. The results indicated that the Suitable Williamson reaction conditions were as follows：n（NaOH）/n（C5H12O3）/n（CH3Cl） = 1.4： 1.0： 1.4,reaction temperatue 90℃ ,reaction time 4 .Oh. The yield of DMDE could reach over 95.0%.