Collect. Czech. Chem. Commun.
1979, 44, 2639-2652
https://doi.org/10.1135/cccc19792639
Kinetics and mechanism of hydrolysis of substituted phenyl N-(4-methylphenyl)sulphonylcarbamates. Solvolysis of 3-nitrophenyl N-(4-methylphenyl)-sulphonylcarbamate in mixtures water-1,4-dioxane and water-tert-butyl alcohol and its decomposition to neutral molecules in non-aqueous media
Jitka Moravcová and Miroslav Večeřa
Organic Chemistry Department, Institute of Chemical Technology, 532 10 Pardubice
Abstract
pH Dependence of hydrolysis rate of the substituted phenyl N-(4-methylphenyl)sulphonylcarbamates has been followed in aqueous medium. The activation parameters and the Hammet reaction constant (ρ = 2.4) have been determined at pH 11.3. For hydrolysis of 3-nitrophenyl N-(4-methylphenyl)sulphonylcarbamate (pK about 3.5) no general base catalysis has been found. The hydrolysis mechanism is discussed. Perturbation of the water structure by organic solvents (1,4-dioxane and tert-butyl alcohol) has been used for differentiation of ElcB and Bac2 mechanisms, 2,4-dinitrophenyl acetate being used for comparison. The decomposition rates of 3-nitrophenyl N(4-methylphenyl)sulphonylcarbamate have been determined in six organic solvents. Mechanism of spontaneous splitting of the carbamate molecule in non-aqueous media is discussed.
