甲基磺酸镧催化合成肉桂酸正丁酯的研究

Study on catalytic synthesis of n-butyl cinnamate with lanthanum methanesulfonate

制备了甲基磺酸镧,并用热重和红外对其进行了表征。热重分析结果表明,所合成的甲基磺酸镧分子中含4个结晶水,La2O3含量的实测值与理论计算值基本相符。研究了以甲基磺酸镧催化肉桂酸和正丁醇的酯化反应,考察了醇酸摩尔比、反应时间和催化剂用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。实验结果表明,甲基磺酸镧催化合成肉桂酸正丁酯的最佳反应条件为:醇酸摩尔比为2∶1,催化剂用量1.0%(以肉桂酸的物质的量计),反应时间120min,反应温度为回流温度。在最佳反应条件下,肉桂酸正丁酯收率在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。甲基磺酸镧重复使用5次后,其催化活性无明显下降,产品收率仍可达到90%以上。

Lanthanum methanesulfonate was prepared and characterized by TGA and FF - IR. The result of TGA indicated that four crystal - water are presented in the formula. The content of lanthanum oxide determined by TGA is-in good agreement with theoretical calculated value. It was used as the catalyst in the esterification of cinnamic acid with butanol. The effects of alcohol / acid molar ratio, reaction time and amount of catalyst have been investigated. The products was characterized by means of refractive index, elemental analysis and FF - IR . The yield can be over 96% under the optimum conditions that molar ratio of butanol to cinnamic acid, 2： 1; a- mount of catalyst, 1.0% （molar percentage of cinnamic acid） ;120 minutes reaction time and reflux temperature. The catalyst can be reused by simple phase - separation after reaction. It is used repeatedly for 5 times without obvious loss of activity and with the yield still is over 90.0%.