H. Hsiao, H. Weng
Jun 19, 1999
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0
Influential Citations
12
Citations
Journal
Industrial & Engineering Chemistry Research
Abstract
As the first part of a series of studies aimed at synthesizing 2-phenoxyisobutyric acid ethyl ester by tri-liquid-phase catalysis, this work investigates the factors influencing the formation of a third liquid phase. In this tri-liquid-phase system, without adding a hard base, 2-bromoisobutyric acid ethyl ester is used as an organic substrate, sodium phenolate (NaOPh) as an aqueous nucleophilic reagent, and tetra-n-butylammonium bromide (QBr) as a phase-transfer catalyst. The factors influencing the formation include the total amount of NaOPh and QBr added, mole fractions of NaOPh and QBr, kinds of organic solvent, kinds and amount of salt, and operating temperatures. Experimental results indicate that in addition to classifying changes in the volume and Q+ concentration of the third liquid phase into three categories according to the mole fraction of QBr, such changes are rationalized by the solubilities of the products of the reaction among NaOPh, QBr, and water and the complexes subsequently formed. Mo...