水杨酸甲酯,俗称冬青油。利用水杨酸和甲醇为原料,在浓 H_2SO_4催化下进行酯化反应制得。酯化反应是一种可逆反应。根据化学平衡移动原理,过量的甲醇有利于酯的生成,若能将反应中生成的水及时除去,也有利于提高酯的产率。根据现有的文献,反应中生成水的除去是单独利用 H_2SO_4做脱水剂,其缺点是易使反应中的有机物炭化,使酯的产率降低。如何将反应中生成的水及时除去,又不致于使过多的有机物炭化是本实验的关键所在。为此我们设想采用双管齐下内外夹攻的办法,即内加少量浓H_2SO_4作脱水剂和外加生石灰的吸水装置。具体的装置是将定量的生石灰放入圆筒内,再把 Methyl salicylate, commonly known as wintergreen oil. The use of salicylic acid and methanol as raw materials, concentrated H_2SO_4 catalytic esterification reaction obtained. Esterification is a reversible reaction. According to the principle of chemical equilibrium shift, excess methanol is conducive to the formation of esters, if the reaction can be generated in time to remove water, but also help to improve the ester yield. According to the existing literature, the removal of generated water in the reaction is the use of H 2 SO 4 alone as a dehydrating agent, which has the disadvantage of easily carbonizing the organic substance in the reaction and reducing the yield of the ester. How to remove the water generated in the reaction in a timely manner, but also not to make too much carbonization of organic matter is the key to this experiment. To this end, we envisaged a two-pronged approach both inside and outside the attack, that is, adding a small amount of concentrated H_2SO_4 dehydration agent and the addition of quicklime absorbing device. The specific device is the amount of quicklime into the cylinder, and then