16917-09-2Relevant articles and documents
Oxidation of ethanolamines by sodium N-bromobenzenesulfonamide in alkaline buffer medium: A kinetic and mechanistic study
Puttaswamy,Vaz, Nirmala,Made Gowda
, p. 480 - 490 (2001)
The kinetics of oxidation of ethanolamines, monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA), by sodium N-bromobenzenesulfonamide or bromamine-B (BAB) in alkaline buffer medium (pH 8.7-12.2) has been studied at 40°C. The three reactions follow identical kinetics with first-order in [oxidant] and fractional-order each in [substrate] and [OH-]. Under comparable experimental conditions, the rate of oxidation increases in the order: DEA > TEA > MEA. The added reaction product, benzenesulfonamide, retards the reaction rate. The addition of halide ions and the variation of ionic strength of the medium have no significant effect on the rate. The dielectric effect is negative. The solvent isotope effect k′(H2O)/k′(D2O) ≈ 0.92. Activation parameters for the composite reaction and for the rate-limiting step were computed from the Eyring plots, Michaelis-Menten type of kinetics is observed. The formation and decomposition constants of ethanolamine-BAB complexes are evaluated. An isokinetic relationship is observed with β = 430 K indicating that enthalpy factors control the rate. For each substrate, a mechanism consistent with the kinetic data has been proposed.
Oxidation of indigo carmine by N-haloarenesulfonamidates: A kenetic study
Puttaswamy,Mahadevappa,Rangappa
, p. 3343 - 3348 (1989)
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Bromamine-B/PdCl2 is an efficient system for the synthesis of anthranilic acids from indoles and indigos
Kumar, C. Vinod,Shivananda,Raju, C. Nagu,Jagadeesh
experimental part, p. 3480 - 3487 (2011/02/22)
A convenient method has been developed for the conversion of indoles and indigos into anthranilic acids in good to excellent yields using a bromamine-B/PdCl2 system. The general process utilizes our efficient method for the oxidation of indoles and indigos in alkaline (pH 12) acetonitrile/water (1:1) at 60°C. Copyright Taylor & Francis Group, LLC.
Kinetic analysis of oxidation of dipeptides by sodium N-bromobenzenesulfonamide in acid medium: A mechanistic approach
Puttaswamy,Vaz, Nirmala
, p. 73 - 80 (2007/10/03)
The kinetics of the oxidation of five dipeptides (DPP) viz., glycylglycine (Gly-Gly), L-alanyl-L-alanine (Ala-Ala), L-valyl-L-valine (Val-Val), L-leucyl-L-leucine (Leu-Leu), and phenylglycyl-phenylglycine (Phg-Phg) by sodium N-bromobenzenesulfonamide or bromamine-B (BAB) in presence of HClO4 was studied at 40 °C. The five reactions followed identical kinetics with a first-order dependence on [BAB] and fractional order in [DPP]. At [H+] > 0.04 mol dm-3, the rate was inverse fractional in [H+], but zero order at lower [H+] (≤ 0.04 mol dm-3). A variation of the ionic strength or dielectric constant of the medium and the addition of halide ions and benzenesulfonamide had no effect on the rate of the reaction. Proton inventory studies were made in H2O-D2O mixtures for all five dipeptides. A Michaelis-Menten type mechanism has been suggested to explain the results. The decomposition and equilibrium constants were evaluated. The oxidation products were identified. The isokinetic temperature was 360 K, indicating the enthalpy to be a controlling factor. The rate of oxidation increased in the order Phg-Phg > Ala-Ala > Val-Val > Leu-Leu > Gly-Gly. The kinetics of oxidation of dipeptides was compared with those of their corresponding monomer amino acids, namely Phenylglycine, alanine, valine, leucine, and glycine. A general mechanism was proposed and the derived rate law are consistent with the observed kinetics.
