以硅胶为催化剂,通过微波辐射加热,实现了无溶剂条件下乙酰水杨酸的合成.利用核磁共振波谱、红外光谱等对目标产物进行了表征.讨论了乙酸酐/水杨酸比例、催化剂用量、微波功率、辐射时间、反应温度对反应的影响.确定了最优反应条件:水杨酸 :乙酸酐 :硅胶催化剂为1 : 2 : 0.3(mol),微波功率为300W,反应时间为15min,反应温度70℃.在此条件下,产率87%.并提出了可能的反应机理.新方法反应条件温和,收率较高.%Under microwave irradiation,acetylsalicylic acid was synthesized with salicylic acid and acetic acid anhydride as raw ma-terials by employing silica gel as catalyst without solvent.The structure of the product was characterized by means of IR and NMR. The influence of material ratio,microwave radiation power and time,reaction temperature on the product yield were respectively dis-cussed,and the optimum synthetic process conditions were ascertained as follows:n(acetic acid anhydride): n(salicylic acid): n (catalyst)=1 : 2 : 0.3(mol),the microwave radiation power of 300W,the reaction time of 15min,the reaction temperature of 70℃,under such optimum conditions,the product yield was 87%.The possible reaction mechanism was proposed.Compared to the classic reaction,the main advantages of the present procedure were milder conditions and higher yields.
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