- 期刊
Kinetics of the Replacement of Ethyl-2-Bromoisobutyrate with Phenol under Phase-Transfer Catalysis Conditions
在相間轉移觸媒催化條件下2-溴異丁酸乙酯和酚化合物取代反應之動力學研究
摘要
本研究乃探討2-溴異丁酸乙酯(ethyl-2-bromoisobutyrate,EtOBuBr)和酚化合物(phenol)在KOH齡性水溶液／有機溶劑二相中合成2-笨氧基異丁酸乙 酯(ethyl-2-phenxyisobutyrate)之相間轉移觸媒催化反應。基於此，溴化四丁基銨(TBAB)做爲相間轉移觸媒。同時，又基於2-溴異丁酸乙酯在水中及在有機溶劑中之溶解度關係，在本研究提出了在有機相和在水相間之界面反應機構探討反應物之取代和水解反應。在反應溶液中每一成分這濃度皆由質量均衡求得，反應物(2-溴丁酸乙酯，EtOBuBr)和産物(R1OR2COOR3)之水解和取代反應皆同時在動力模式中加以考慮，在反應動力學方面，攪拌速率、有機溶劑、酚化合物濃度及TBAB觸媒用量在對EtOBuBr之水解及取代這轉化率及R1OR2COOR3之産率皆做深入之研究。
關鍵字
無資料並列摘要
This work investigates the phase transfer catalytic replacement of ethyl-2-bro-moisobutyrate (EtOBuBr) with phenol in the synthesis of ethyl-2-phenoxyisobutyrate (R1OR2COOR3, ester-ether compound) in an alkaline aqueous solution of KOH/organic solvent two-phase medium. In this substitution, tetrabutylammonium bromide (TBAB) acts as the phase transfer catalyst. Based on the solubility of (EtOBuBr) in aqueous solution and in an organic solvent, a mechanism for the reaction on the interface between the organic and aqueous phases is proposed. The concentration of each component in the reaction solution was determined experimentally from the material balance. Hydrolysis of EtOBuBr (reactant) and R1OR2COOR3 (ether-ester product) accompanied by the above substitution are both considered in the kinetic model. This work also investigates the kinetics of the reaction, such as the effects of the agitation speed, organic solvents, concentration of phenol (aqueous- phase reactant) and amount of TBAB catalyst on the conversion of hydrolysis, the replacement of EtOBuBr, and the yield of R1OR2COOR3.