Esterification Amberlyst-15 catalyzed

Yuen et al. [24] first demonstrated the nature of the information that can be obtained regarding chemical mapping within a fixed-bed reactor, using the liquid phase esterification of methanol and acetic acid catalyzed within a fixed bed of H+ ion-exchange resin (Amberlyst 15, particle size 600-850-pm) catalyst as the model... 

The effect of the mode of heating was also studied in heterogeneously catalyzed esterification of acetic acid by isopentyl alcohol in the presence of Amberlyst-15 cation exchange resin catalyst [38], Scheme 10.2. 

W. Yu, K. Hidajat, A. K. Ray, Determination of adsorption and kinetic parameters for methyl acetate esterification and hydrolysis reaction catalyzed by Amberlyst 15. Appl. Catal. A, 2004, 260 (2), 191-205. 

Sulfonic acid resins can be used as solid catalysts for esterifications and other acid-catalyzed reactions. Am-berlyst 15 was a more effective catalyst for the preparation of esters of phenethyl alcohol and cyclohexanol than sulfated zirconia, an acid clay, and dodecatungstophos-phoric acid.113 (Amberlyst and Amberlite are trademarks of Rohm Haas.) (See Chap. 6 for more detail on solid acids and bases.) The same catalyst gave 86-96% yields of hydroxyesters when a lactone was stored with a hy-droxyacid.114 Diols can be monoacylated in 58-92% yields by transesterification with ethyl propionate in the presence of Dowex 50W (a product of the Dow Chemical Co.).115 Modification of the sulfonic acid resin with 2-mercaptoethylamine produced a catalyst for the reaction of phenol with acetone to produce bisphenol A (5.30) in 99.5% yield.116 After 20 cycles the yield was still 98.7%. When used as catalysts, ion-exchange resins can last for 6 months to 2 years. 

By reaction of phenols with bifunclional molecules, which are able to alkylate and to esterify, several coumarin derivatives have been prepared using H-Bela as the catalyst. Thus resorcinol and propynoic acid react at 150 °C in p-chlorotolucnc as the solvent towards the perfumery ingredient umbelliferone (7-hydroxycoumarin) in good yield, 60 %, [84], Amberlyst-15 gave 40 % yield. II-Beta catalyzes the esterification as well as the ring closure alkylation step. 

Another solid-aeid catalyzed reaction in which the Nafion-silica composites are much more active than the non-supported pure resin and Amberlyst-15 is the addition-esterification of carboxylic acids to cyclic olefins. For example, the addition of saturated carboxylic acids to dicyclopentadiene, leading to starting esters for the flavor and fragrance industry [27]. 

Esterification. At room temperature, saturated carboxylic acids are selectively esterified with an alcohol in the presence of Amberlyst-15 resin. Alkenoic and aroic acids are left unreacted. Transesterification of alkyl formate to a dicarboxylic acid forming the monocarboxylic ester is catalyzed by Dowex-50WX2. ... 

Ion-exchange resins, especially the cation-exchange resins such as Dowex, Amberlyst series are manufactured mairJy by sulfonation of ethylbenzene first, followed by a cross-link with divinylbenzene (Liu Tan, 2001 Alexandratos, 2008 Tesser et al., 2010). Because of their selective adsorption of reactants, surface acid site features, and swelling nature, these resins not only catalyze the esterification reaction but also affect the equilibrium conversion. They also show excellent performance such as reusable, mechanical separation, continuous operation as a heterogeneous catalyst in esterification (Yang et al., 2007 JagadeeshBabu et al, 2011 Ju et al, 2011 Toor et al., 2011). 

Schmid, B., M. Doker J. Gmehling (2008) Esterification of Ethylene Glycol with Acetic Acid Catalyzed by Amberlyst 36. Industrial Engineering Chemistry Research, 47, 698-703,lSSN 0888-5885. 

Shimizu and Hirai (1987) studied the solvent effect on the kinetics of resin catalyzed esterification of octanoic acid with 1-butanol catalyzed by macroreticular sulfonic acid resin (Amberlyst 15) in the presence of various organic solvents and water. They concluded that the extent of the selectivity of the resin catalyst depend on the alkyl... 

Kumbhar and Yadav (1989) proposed a model for solid-catalyzed liquid phase reactions. A power law model was used to describe the surface reaction. Later, Yadav and Mehta (1994) applied this model to heterogeneous catalytic esterification. Patwardhan and Sharma (1990) also used the power law model to fit their experimental data for the esterification of carboxylic acids with olefins using cation ion exchange resins. They found that Amberlyst 15 had the highest activity among various catalysts. 

The kinetics and equilibrium of autocatalyzed and ion exchange resin (Amberlyst-15) catalyzed esterification of acetic acid with methanol and hydrolysis of methyl acetate were studied by Popken et. al. (2000) in a temperature range of 303 - 343 K. The homogeneous reaction has been described with a simple power-law model. To compare pseudo-homogeneous and adsorption-based kinetic models for the heterogeneously catalyzed reaction, independent binary liquid phase adsorption experiments were used to estimate the adsorption equilibrium constants to keep the number of adjustable parameters the same for each model. 

---