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Oxidation of substituted phenethyl alcohols by sodium N‐chlorobenzenesulphonamide: A kinetic study
Author(s) -
Ramachandra H.,
Rangappa K. S.,
Mahadevappa D. S.
Publication year - 1996
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/(sici)1099-1395(199607)9:7<439::aid-poc777>3.0.co;2-v
Subject(s) - chemistry , kinetic isotope effect , reaction rate constant , enthalpy , ionic strength , kinetics , sodium , reaction rate , order of reaction , activation energy , medicinal chemistry , organic chemistry , catalysis , aqueous solution , deuterium , thermodynamics , physics , quantum mechanics
The kinetics of the oxidation of six substituted phenethyl alcohols by sodium N ‐chlorobenzenesulphonamide or chloramine‐B (CAB) in the presence of HCl was studied at 35°C. The rate shows a first‐order dependence on [CAB] 0 and [H + ] and is fractional order in [PEA] 0 and [Cl − ]. Ionic strength variations, addition of reaction product of benzenesulphonamide and variation of the dielectric constant of the medium have no effect on the rate. The solvent isotope effect k 1 H 2 O/ k 1 D 2 O ≅ 0·78. Proton inventory studies were made in H 2 O‐D 2 O mixtures. The rates correlate satisfactorily with the Hammett linear free energy relationship. The reaction constant ρ was −3 · 5 for electron‐releasing and −0·30 for electron‐withdrawing groups at 35°C. Activation parameters Δ H *, Δ S *, Δ G * and log A were calculated for the reaction. An isokinetic relationship is observed with β = 338 K, indicating enthalpy as a controlling factor.