A Method for Esterification Reaction Rate Prediction of Aliphatic Monocarboxylic Acids with Primary Alcohols in 1,4‐Dioxane Based on Two Parametrical Taft Equation

Abstract

Esterification reaction rates of aliphatic monocarboxylic acids with primary alcohols in 1,4-dioxane as inert solvent were investigated. Acids were esterified with 1-propanol and alcohols with acetic acid as model reactants at a constant temperature of 60 • C, at a fixed ionic strength and pH in a batch reactor with a constant volume. For evaluation of reaction rates, an exact kinetic equation for the equilibrium reaction was applied. Under these conditions and for low reactants, concentrations reaction rate depends only on the structure of reactants and, therefore, can be predicted by a correlation equation with two Taft coefficients (inductive and steric effects). From these equations, it is possible to estimate the esterification reaction rate constant for other acid-alcohol pairs. This methodology may also be suitable for other kinetic systems measured under comparable experimental conditions. C

DFT study of the acid‐catalyzed esterification reaction mechanism of methanol with carboxylic acid and its halide derivatives

“…The production of MeOAc from HOAc and MeOH has been kinetically mediated by homogeneous or heterogeneous catalysts, with more research being performed on the latter due to increased reusability, high selectivity, and less product contamination . The synthesis and kinetics via microwave, membrane, batch, and microchannel reactors have also been addressed .…”

“…The production of MeOAc from HOAc and MeOH has been kinetically mediated by homogeneous or heterogeneous catalysts, with more research being performed on the latter due to increased reusability, high selectivity, and less product contamination . The synthesis and kinetics via microwave, membrane, batch, and microchannel reactors have also been addressed . Most recent experimental investigations (from 2011) have reported free energy of activation for this process with values ranging from ∼7.7 to 15.1 kcal mol −1 in different reaction media/solvents at temperature up to 333 K. In addition to this parameter, some studies also provided heat of reaction (enthalpy, Δ H ) and entropy (Δ S ) of activation values within −1.0 and 0.1 kcal mol −1 for Δ H while 1.0 E −5 and 0.1 cal (mol K) −1 for the reaction entropy …”

Prediction of esterification rate constants for secondary alkan-2-ols based on one- and two-parameter Taft equations

“…The kinetics of esterification for secondary alkan-2-ols with acetic acid at 60°C were measured as in our previous paper. 1 The equilibrium constants K C (given in Table 3) were used for the calculation of the rate constants k E (refer to equation (4)). The results acquired are shown in Table 4.…”

“…Esters of secondary alcohols with organic acids, like esters of primary alcohols, 1,2 have been applied in industrial production of fragrances and aromas. For example, propan-2-yl acetate is used in the preparation of apple aromas (FEMA 2926), propan-2-yl propionate for plum- or raspberry-type aromas (FEMA 2959), cyclohexyl acetate for raspberry-, banana-, or pineapple-type aromas (FEMA 2349), and cyclohexyl butyrate for pineapple or apple aromas, or jasmine scents (FEMA 2351).…”

“…This article is an attempt to determine experimentally a correlation equation of Taft-type for one and two parameters (including coefficients for steric and inductive effects) for the esterification of secondary alkan-2-ols with monocarboxylic organic acids. This equation was combined with previous results 1 leading to an equation according to which it is possible to predict the esterification rate constants of secondary alkan-2-ols with any monocarboxylic acid without experimental measurements. This methodology can be applied in ester synthesis and the food and perfume industries for the calculation of reaction time expenses for the production of these materials.…”