摘要
在常压、无溶剂条件下,以聚乙二醇(PEG)为相转移剂,钾盐为催化剂,碳酸乙烯酯(EC)和硫醇(RSH)为原料合成了β-羟乙基烷基硫醚(RSCH_(2)CH_(2)OH)。系统考察了PEG对不同钾盐在RSH的β-羟乙基化反应中的固/液相转移作用以及EC用量对RSCH_(2)CH_(2)OH选择性的影响。通过GC和GC-MS计算与测定RSH转化率、RSCH_(2)CH_(2)OH选择性和副产物。结果表明,PEG本身没有催化活性,与单独加入0.5%(以RSH物质的量为基准,下同)K_(2)CO_(3)相比,同时加入1.0%PEG和0.5%K_(2)CO_(3)可显著提高RSH转化率和反应速率。PEG相对分子质量<1000时,PEG对K_(2)CO_(3)催化活性的强化作用随着PEG链长度的增长而增强。RSCH_(2)CH_(2)OH的选择性随着EC与RSH物质的量比(≥1.02)的增大而降低,副产物为乙烯基烷基硫醚和乙二醇。无溶剂条件下,PEG的加入能有效打破钾盐催化剂与液相反应物之间的相界面限制,增强钾盐催化活性,缩短反应时间,提高产品收率。
Hydroxyethyl alkyl sulfide(RSCH_(2)CH_(2)OH)was synthesized by using polyethylene glycol(PEG)as phase transfer agent,potassium salt as catalyst,ethylene carbonate(EC)and mercaptan(RSH)as raw materials under atmospheric pressure and solvent-free.The effect of PEG on the solid/liquid phase transfer of different potassium salts in theβ-hydroxyethylation of RSH and the effect of EC dosage on the selectivity of RSCH_(2)CH_(2)OH were investigated.The conversion of RSH,selectivity of RSCH_(2)CH_(2)OH and by-products were analyzed by GC and GC-MS.The results showed that PEG itself had no catalytic activity.Compared with the addition of 0.5%(based on the molar amount of substance of RSH,the same below)K_(2)CO_(3) alone,the addition of 1.0%PEG and 0.5%K_(2)CO_(3) could significantly improve the conversion rate of RSH and reaction rate.The enhancement effect of PEG on the catalytic activity of K_(2)CO_(3) increased with the increase of the length of PEG chain when relative molecular mass of PEG was less than 1000.The selectivity of RSCH_(2)CH_(2)OH decreased with increasing the molar ratio of EC/RSH(≥1.02),the by-products were vinyl alkyl sulfide and ethylene glycol.The addition of PEG could effectively break the phase interface limitation between potassium salt catalyst and liquid phase reactants,enhance the catalytic activity of potassium salt,shorten the reaction time and increase the product yield under solvent-free condition.
作者
卢宁
宫红
姜恒
王锐
李飞
LU Ning;GONG Hong;JIANG Heng;WANG Rui;LI Fei(School of Petrochemical Engineering,Liaoning Petrochemical University,Fushun 113001,Liaoning,China)
出处
《精细化工》
EI
CAS
CSCD
北大核心
2021年第12期2539-2545,共7页
Fine Chemicals
基金
辽宁省自然科学基金指导计划项目(2019-ZD-0053)。
关键词
硫醇
羟乙基化
聚乙二醇
固/液相转移
碳酸乙烯酯
催化技术
mercaptan
hydroxyethylation
polyethylene glycol
solid/liquid phase transfer
ethylene carbonate
catalysis technology
