摘要
在微型高压反应釜中 (12 0ml) ,考察了酸催化三聚甲醛和甲酸甲酯制备羟基乙酸甲酯的偶联反应 ,并对酸催化剂中H+的作用进行了研究。在该偶联反应体系中 ,H+浓度直接影响着甲酸甲酯的分解速率和羟基乙酸甲酯的收率。甲酸甲酯在偶联反应中是以CO和CH3OH的载体形式而存在。在H+的催化作用下 ,该偶联反应机理可分三步完成 :(a)H+的催化作用促使甲酸甲酯分解产生CO和CH3OH ,三聚甲醛分解形成羟甲基正离子和甲氧基甲基正离子HOC H2 ;(b)羟甲基正离子CH3OC H2 和甲氧基甲基正离子与CO进行羰化作用形成产物中间体或过渡态化合物 ;(c)中间体或过渡态化合物的甲醇醇解形成羟基乙酸甲酯、甲氧基乙酸甲酯和乙醇酸。
Acid catalyst and H + catalysis in the acid catalysts were studied for synthesis of methyl glycolate via coupling of methyl formate and trioxane in a microform high-pressure autoclave(120mL).H + concentration in the reaction system directly effected on the decomposition rate of methyl formate and the yield of methyl glycolate,and methyl formate was carrier of CO and CH 3OH.Catalyzed by the H + in the coupling reaction,three steps could be involved in the coupling reaction mechanism:First,methyl formate decomposes to CO and CH 3OH,and trioxane decomposes to HO C H 2 and CH 3O C H 2.Then,carbonylation of HO C H 2 and CH 3O C H 2 with CO produces intermediate products or transition state compounds.Third,methanolysis and hydrolysis of intermediate products or transition state compounds lead to methyl glycolate,methoxy acedic methyl ester and glycolic acid.
出处
《石油与天然气化工》
CAS
CSCD
北大核心
2002年第2期55-57,60,共4页
Chemical engineering of oil & gas
基金
鲁南水煤浆汽化与煤化工国家工程中心
国家自然科学基金资助 2 97730 4 6。
