肉桂酸正丁酯的非酸催化合成

Nonacidic catalytic synthesis of n-butyl cinnamate

制备了非酸催化剂甲基磺酸铜,采用热重分析和红外光谱对其进行表征。热重分析结果表明,所合成的甲基磺酸铜分子中含4个结晶水,CuO含量的实测值与理论计算值基本相符。研究了以甲基磺酸铜催化肉桂酸和正丁醇的酯化反应,考察了醇酸物质的量比、反应时间和催化剂加入量对反应结果的影响,对合成的产品用折光率、元素分析和红外光谱进行了表征。结果表明,甲基磺酸铜催化合成肉桂酸正丁酯的最佳反应条件为:醇酸物质的量比为2.0:1.0,催化剂加入量0.30%(以内桂酸物质的量计),反应时间120 min,反应温度为回流温度。在最佳反应条件下,肉桂酸正丁酯收率达96%以上。反应结束后,催化剂通过简单的相分离即可重复使用。甲基磺酸铜重复使用5次后,其催化活性无明显下降,产品收率仍可达到90%以上。

Nonacidic catalysts, copper methanesulfonate, were prepared and characterized by TGA and FT-IR. The TGA results indicated that there existed four crystal water molecules in the formula. The copper oxide content determined by TGA was in good agreement with theoretically calculated value. Copper methanesulfonate was used as the catalyst for esterification of cinnamic acid with butanol. The effects of alcohol/acid molar ratio, reaction time and catalyst dosage were investigated. The products were characterized by means of refractive index, elemental analysis and FT-IR. n-Butyl cinnamate yield of over 96% was obtained under the optimum condition as follows： butanol to cinnamic acid molar ratio of 2.0： 1.0, catalyst dosage of 0.30% （molar percentage of cinnamic acid）, reaction time 120 min, reaction temperature of the same as reflux temperature. The catalyst was reusable after simple phase-separation and could be repeatedly used for 5 times without obvious loss of activity and with n-butyl cinnamate yield of over 90.0%.