• 作者： Yang, Hung-Ming; Chen, Tsan-Ming
• 中文摘要： 本文探討應用固-液相相間轉移觸媒催化乙基2-溴異丁酯之醚化反應來合成醚酯化合物及其反應動力學，其中固相反應物為4-苯甲氧基苯氧化鉀。以此無水之固-液相相間轉移催化反應系統可避免酯類在強鹼水相/有機相之水解反應發生，並可獲得乙基2-溴異丁酯醚化之高轉化率。研究中探討攪拌速率、不同觸媒、反應溫度、溶劑種類、觸媒用量等效應，實驗結果可以虛擬一次反應動力式來描述，同時對添加微量水之反應亦一併探討。結果顯示，攪拌速率超過 350rpm即不影響反應，轉化率隨溶劑極性之增加、溫度之增加而增加，以溴化四丁基銨為觸媒之反應活化能為15.2kcal/mol，添加微量水可促進觸媒之反應性。
• 英文摘要： Phase transfer catalyzed reactions such as esterification, hydrolysis, and halide exchange were reported to conduct successfully in solid-liquid phase transfer catalysis (SLPTC). In the present work, the kinetics for synthesizing ether-esters from the etherification of ethyl 2-bromoisobutyrate under solid-liquid phase transfer conditions was investigated. The reaction was carried out in a stirred batch reactor with isothermal jacket, using potassium 4-benzy-loxyphenoxide as the solid reactant. The potassium salt was prepared from deprotonation of 4-benzyloxyphenol with potassium hydroxide in aqueous solution. Using the solid/liquid system, the usual hydrolysis of ester compounds in alkali aqueous/organic phases can be prevented under anhydrous conditions. High conversion of etherification of ethyl 2-bromoisobutyrate in organic solvent can be obtained. The experimental data were described by pseudo-first-order kinetics. Various quaternary 'onium salts were employed to compare their efficiencies for etherification. Effects of agitation speed, reaction temperature, organic solvent and small quantities of water addition were explored to find the optimal operating conditions. From the experimental results, the reaction rates are not influenced by the stirring speed when the agitation speed exceeds 350rpm. The reaction rate increases with increasing the polarity of solvent. The temperature effects as well as the activation energy for various phase transfer catalysts were investigated. The activation energy for TBAB was calculated to be 15.2Kcal/mole. Small quantities of water addition can also enhance the reactivity of catalyst.
• 中文關鍵字： 相轉移催化; 動力學; 醚化; 醚酯; 乙基溴異丁酸
• 英文關鍵字： Phase Transfer Catalysis; Kinetics; Etherification; Ether Ester; Ethyl Bromoisobutyrate