Effects Of Mixed Aqueous-Organic Cosolvents On The Rates Of Cleavage Of N-(2'-Hydroxyphenyl)Phthalimide (1) And N-(2'-Methoxyphenyl)-Phthalimide (2) In Alkaline Media
Document Type
Article
Publication Date
1-1-2007
Abstract
The effects of mixed H2O-OCS (where organic cosolvents (OCS) = methanol, ethanol, 1-propanol, 2-propanol, 1,4-dioxan and acetonitrile) on the first-order rate constants, k(obs), for hydrolysis of I at 1.0 X 10(-3) M NaOH and 2 at 2.0 x 10(-3) M NaOH show a nonlinear decrease in k(obs), with increasing contents of OCS. The k(obs), - decreasing sensitivity of mixed H2O - OCS solvents within 5 X% v/v OCS, where X ranges from 50 to 90, is ca 2- to 9-fold larger for hydrolysis of 2 than that of 1. This observed characteristic difference is attributed to the occurrence of different rate laws in these reactions, i.e. rate = k(w) [1(-)][H2O] and rate = k(OH) [2][HO-] in the hydrolyses of 1 and 2, respectively.
Keywords
mixed h2o-ocs, methanol, ethanol, 1-propanol, 2-propanol, 1, 4-dioxan, acetonitrile, first-order rate constants, hydrolysis, ionized phenyl salicylate, structure-reactivity correlations, base-catalyzed cleavage secondary-amines, acyl transfer, hydrolysis, kinetics, mechanism, solvents, esters
Divisions
CHEMISTRY
Publication Title
Progress in Reaction Kinetics and Mechanism
Volume
32
Issue
2
Additional Information
Department of Chemistry, Faculty of Science Building, University of Malaya, 50603 Kuala Lumpur, MALAYSIA