3,5-二羟基苯甲酸甲酯催化加氢制备3,5-二羟基甲苯及反应历程研究  

PREPARATION AND REACTION MECHANISM OF 3,5-DIHYDROXYTOLUENE FROM METHYL 3,5-DIHYDROXYBENZOATE BY CATALYTIC HYDROGENATION

作　　者：陆樊委 张伟[1] 鲁墨弘[1] 李明时[1] 单玉华[1] 朱建军[1] 

机构地区：[1]常州大学石油化工学院,江苏常州213164

出　　处：《精细石油化工》2015年第2期63-67,共5页Speciality Petrochemicals

基　　金：国家自然科学基金(20976076;21307009)

摘　　要：制备了Cu-Zn-Al催化剂,用于3,5-二羟基苯甲酸甲酯加氢反应。考察了加氢工艺条件及羟基对苯环加氢的影响。结果表明:在反应温度200℃和压力8 MPa下,反应时间3h,3,5-二羟基苯甲酸甲酯的转化率为80.5%,3,5-二羟基甲苯的选择性为97.7%。反应生成的3,5-二羟基甲苯易被进一步加氢生成3-甲基环己醇;苯环上羟基的存在,使苯环的电子云密度增加,从而使苯环活化,易被进一步加氢;苯环上的醛基和羟甲基容易被进一步加氢,验证了3,5-二羟基苯甲酸甲酯加氢经3,5-二羟基苯甲醛和3,5-二羟基苯甲醇,进一步加氢生成3,5-二羟基甲苯的反应历程。Different catalysts were prepared for the synthesis of 3,5-dihydroxytoluene by hydrogena-tion of methyl 3,5-dihydroxybenzoate and their catalytic performance were evaluated.Results showed that high selectivity of 97.7% to 3,5-dihydroxytoluene with 80.5% conversion of methyl 3,5-dihydroxybenzoate was obtained over the selected Cu-Zn-Al catalyst under reaction conditions of 200 ℃and 8 MPa at the reaction time of 3h.The benzene ring of 3,5-dihydroxytoluene was unstable in the reaction conditions which resulted in the formation of 3-methylcyclohexanol.Hydroxyl in benzene ring increased the electron cloud density of benzene ring,which led to activation of benzene ring and benzene ring was easy to be further hydrogenated.Aldehyde group and hydroxymethyl in benzene ring was unstable and easy to be further hydrogenated.It is proposed that hydrogenation of methyl 3,5-dihydroxybenzoate resulted in the formation of the intermediates of 3,5-dihydroxybenzaldehyde and 3,5-dihydroxybenzyl alcohol which were unstable and easy to be further hydrogenated to 3,5-dihydroxytoluene.

关 键 词：铜锌铝催化剂 3 5-二羟基苯甲酸甲酯 3 5-二羟基甲苯 反应历程 

分 类 号：TQ243.1[化学工程—有机化工]