4-Methoxyphenyl dichloroacetate hydrolysis

It is well-known that at-PMMA maintains a compact-coil conformation below pH 4.5 and an extended-coil conformation above pH = 5.5. The conformational transition takes place in the intermediate pH region. Thus, the kinetic effects will reflect the influence of the compact coil of PMAA. Changes in the pseudo-first-order rate constants (/Jobsd) neutral hydrolysis of p-methoxyphenyl dichloroacetate... 

Blokzijl, W., Engberts, J.B.E.N. Jager, J.B. and Blandamer, M.J., Description of solvent dependence of rate constants in terms of pairwise group Gibbs function interaction parameters. Medium effects for hydrolysis of p-methoxyphenyl dichloroacetate in aqueous solutions containing urea and alkyl-substituted ureas, /. Phys. Chem., 1987, 91, 6022-6027. 

The imidazole-catalysed hydrolysis of polar substituted 2,4-dinitrophenyl acetates (21 X = Cl, OMe) has been investigated at different temperatures. The observed rates correspond to the bimolecular nucleophilic addition of the imidazole at the carboxylic carbon atom followed by a very fast hydrolysis of the (V-acetylimidazole in water. The influence of polar substituents in the acid moiety of the ester molecule on the hydrolysis reaction can be described by an electrostatic dipole-dipole interaction in the same way as the neutral hydrolysis of polar substituted ethyl acetates. By the use of both quantum and classical dynamics, a study of the neutral hydrolysis of 4-methoxyphenyl dichloroacetate (22) in water concluded that the rate-determining step is a proton transfer concerted with formation of a C-O bond. ... 

The kinetics of the neutral hydrolysis of 4-methoxyphenyl 2,2-dichloroacetate in aqueous solution have been studied in the presence of varying amounts of MeCN, THF and polyethylene glycol (PEG 400) in order to assess the role of solvent activity and solute-solute interactions.14... 

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