144-86-5

L-glutamic acid is used in the production of monosodium glutamate spices and other biochemical reagents. Its oxidation kinetics and a detailed mechanistic interaction of Os(VIII) catalyzed Glue-CAT reaction in alkaline medium have been investigated at different temperatures. It has been studied spectrophotometrically as a basic experimental approach for this study. All variables affecting the development of the color were investigated and the conditions were optimized. The effect of Glue, CAT, Os(VIII), and OH concentration on the rate of reaction has been studied. The reactions follow identical kinetics for all It is a first order reaction in both Glue and CAT, but fractional order in alkali and Os(VIII). Increasing ionic strength dielectric constant of the medium had no significant effect on the rate. The effects of added products like halide ions and toluene-p-sulfonamide have also been investigated. A mechanism involving the formation of a complex between Glue-CAT-Os(VIII) has been proposed. The stoichiometry of the reaction is found to be 1:1. The main products of Glue were identified with the help of FTIR and TLC. The reaction constants involved in the mechanism are explained. There is a good agreement between the observed and calculated rate constants under different experimental conditions. Investigations at different temperatures allowed the determination of the activation parameters with respect to the slow step of the proposed mechanism. The proposed methods were successfully applied for the high yield of the products and short reaction times. It is also an inexpensive, simple, and smooth method.

The kinetics and mechanisms of chlorine transfer from chloramine-T (CAT) to several amines are second order and independent of p-toluenesulfonamide concentration; thus, the reaction does not involve disproportionation of CAT to dichloramine-T. From the profile of pH versus rate, the following mechanisms were proposed: (1) reaction of the ionized species of CAT with the ionized amine (ionic mechanism) and (2) reaction of the un-ionized species of CAT with the un-ionized amine (nonionic mechanism). The second-order, pH- independent rate constants calculated for the ionic and nonionic mechanisms were 1.6 and 5 x 106 M-1 s-1, respectively. Although these two mechanisms are kinetically indistinguishable, the rate constant for the nonionic mechanism is of the same order of magnitude as those calculated for similar chlorination reactions involving nonionizable chloramines, such as N- chlorosuccinimide, N-chloroquinuclidine, and N-chloro-N- methylbenzenesulfonamide. The proposed mechanism for the chlorine exchange involves a molecule of water in a cyclic, six-membered transition state.

To study the mechanism of N-chlorination of secondary amines by chloramine-T, the kinetics of the reactions of some aromatic-substituted analogues of N-chlorobenzenesulfonamide with various secondary amines were determined. The importance of amine basicity and reactivity of the N-Cl bond of the N-chlorobenzenesulfonamide was also assessed. The results indicate that a mechanism involving the un-ionized species of both reactants (i.e., a molecular mechanism), rather than an ionic mechanism, is operating and that the reaction most likely proceeds via a six-membered-ring transition state that incorporates a water molecule.