Phase-transfer catalytic reaction of ethyl-2-bromolsobutyrate and phenol: Effects of water and temperature

摘要

The phase-transfer catalytic reaction (PTC) of ethyl-2-bromoisobutyrate and phenol for synthesizing ethyl-2-phenoxyisobutyrate was carried out in KOH solution/organic solvent two-phase medium. Tetrabutylammonium bromide (TBAB) was employed as the phase-transfer catalyst. The occurrence of the reaction on the interface between the organic and aqueous phases is discussed. A rational reaction mechanism is proposed here and used to build the kinetic model. Hydrolysis of the bromo-alkyl bond (Br-C bond) and the ester functional group (-COOR) was found to take place in an alkaline aqueous solution. The effects of the amount of water on the conversion of ethyl-2-bromoisobutyrate, the fractional yield of hydrolyzing ethyl-2-bromoisobutyrate, the fractional yield of hydrolyzing ethyl-2-phenoxy-isobutyrate, and the fractional yield of ethyl-2-phenoxyisobutyrate (ether-ester product) are investigated in detail.