Effects of tetraalkylammonium salts on alkaline hydrolysis of N-(2-Methoxyphenyl) Phthalimide

The effects of the concentrations of Me₄NCI, Pr₄NCl, Bu₄NCl, Me₄NBr, Pr₄NBr and Bu₄NBr on the rate of alkaline hydrolysis of N-(2-methoxyphenyl)phthalimide (N-2MPhPT) at 35°C and in H₂0 solvent containing 2 % (v/v) CH₃CN reveal the formation of ion-pair complexes between solvent - separated loose io...

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Bibliographic Details
Main Authors: Ariffin, Azhar, Khan, M.N., Leng, S.Y.
Format: Article
Published: Faculty of Science, University of Malaya 2004
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Online Access:http://eprints.um.edu.my/8043/
http://umrefjournal.um.edu.my/public/article-view.php?id=1985
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Summary:The effects of the concentrations of Me₄NCI, Pr₄NCl, Bu₄NCl, Me₄NBr, Pr₄NBr and Bu₄NBr on the rate of alkaline hydrolysis of N-(2-methoxyphenyl)phthalimide (N-2MPhPT) at 35°C and in H₂0 solvent containing 2 % (v/v) CH₃CN reveal the formation of ion-pair complexes between solvent - separated loose ion-pair forms ($M^n^+$ ⋯ $X^k^-$) and N-2MPhPT. The bulky hydrophobic tails of tetraalkylammonium salts and their halide anions inhibit the reaction by blocking the OH�?� nucleophilic attack on the reactive site of N-2MPhPT. Among all the quaternary ammonium salts, Me₄NCI showed slight inhibition only because of the shielding effect created by the methyl group is very small. However, Bu₄NBr presents the greatest inhibition on hydrolysis rate because of its strong binding affmity with N-2MPhPT.