摘要
该文以1-甲基咪唑、吡啶、苄基氯、硫酸、磷酸为原料,合成了4种Brφnsted酸性离子液体:1-甲基-3-苄基咪唑硫酸氢根盐(a),1-甲基-3-苄基咪唑磷酸二氢根盐(b),N-苄基吡啶硫酸氢根盐(c),N-苄基吡啶磷酸二氢根盐(d),以它们作为催化剂和反应介质,考察了苯甲酸与系列脂肪醇、苄醇与系列脂肪酸、苯甲酸在无溶剂和微波辐射反应条件下的Fischer酯化反应,结果表明,当苯甲酸或苄醇与离子液体的摩尔比为1∶0.5时,无需外加催化剂,反应即可在化学计量条件下进行,12~20 min完成反应,苯甲酸酯与苄酯的收率分别为77%~98%和78%~98.5%,气相色谱纯度≥95%。离子液体循环使用3次,催化活性仅下降1.8%~3.4%。
Four easily accessible Brφnsted acidic ionic liquids, 1-methyl-3-benzylimidazolium hydrogen sulfate,1-methy-3-benzylimidazolium hydrogen phosphate,N-benzylpyridinium hydrogen sulfate,and N- benzylpyridinium hydrogen phosphate, were synthesized from the commercially available starting material N-methylimidazole, pyridine, benzyl chloride, sulphuric acid and phosphoric acid. They act as reaction media and catalyst for the synthesis of benzoic esters and benzyl esters under solvent-free and microwave irradiation conditions. When the mole ratio of benzoic acid or benzyl alcohol to ionic liquid was 1:0.5 ,the reactions proceeded smoothly with equal mole of substrates in 12 -20 min and gave the products in good or excellent yields (77% -98% and 78% -98.5% respectively). The recycled ionic liquids can be used three times without significant loss of catalytic activity.
出处
《精细化工》
CAS
CSCD
北大核心
2008年第3期308-312,共5页
Fine Chemicals
关键词
BRΦNSTED酸
离子液体
微波
苯甲酸酯
苄酯
精细化工中间体
Brφnsted acid
ionic liquids
microwave irradiation
benzoic esters
benzyl esters
fine chemical intermediates