Ru(III)‐Catalyzed Oxidation of Some Amines by Chloramine‐T in Hydrochloric Acid Medium — Mechanistic Aspects and Kinetic Modeling

Abstract

The kinetics of oxidation of five amines viz., ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA), aminoethylpiperazine (AEP) and isophoronediamine (IPDA) by sodium N-chloro-p-toluenesulfonamide or chloramine-T (CAT) in the presence of HCl and Ru(III) chloride was studied at 303 K. The five reactions followed identical kinetics and the experimental rate law is ratez , where x, y and z are fractions. A variation of the ionic strength or dielectric constant of the medium and the addition of halide ions and ptoluenesulfonamide had no significant effect on the rate of the reaction. The solvent isotope effect has been studied in D 2 O medium. The activation parameters have been evaluated from the Arrhenius plots. Under comparable experimental conditions, the rate of oxidation of amines increases in the order: AEP > TETA > DETA > EDA > IPDA. An isokinetic relationship is observed with β = 377 K, indicating enthalpy as a controlling factor.Oxidation products were identified. CH 3 C 6 H 4 SO 2 + NH 2 Cl of the oxidant has been postulated as the reactive oxidizing species. Further, the kinetics of Ru(III)-catalysed oxidation of these amines have been compared with unanalyzed reactions (in the absence of Ru(III) catalyst) and found that the catalysed reactions are 2-3-fold faster. The catalytic constant (K C ) was also calculated for each amine at different temperatures from the plots of log K C against 1/T, values of activation parameters with respect to the catalyst have been evaluated. The observed results have also been explained by a plausible mechanism and the related rate law has been deduced.

<b>Preparation and reactivity studies of maleimidophenyl glycidylether with amines</b>

“…The strong basic condition of the reaction might cause the hydrolysis of the imide groups of HPM and N-MPGE, therefore, to result in mixed by-products. To compensate this flaw, benzyltrimethyl ammonium chloride (BTAC), which was reported being useful in the synthesis of glycidyl phosphinate compounds without causing hydrolysis of the phosphinate compounds [23][24][25][26][27][28], was utilized in the synthesis of N-MPGE. The product yield was significantly raised to about 75%.…”

“…This may be due to the presence of more number of amine groups. This can possibly be credited to the presence of more number of amine groups, and which accelerates the curing rate very much, resulting in the high cross-link density network when compared to other amines [24,25].…”

Oxidation and Reduction

“…TsNH 2 Cl has been postulated as the reactive species and a mechanism has been suggested. 142 The oxidation of glutamic acid to cyanopropionic acid with CAB in acid solution showed an inverse fractional dependence on acidity. Similarly in alkaline medium, the order in alkali is fractional inverse.…”

Flow-injection spectrophotometric determination of tetracycline and doxycycline in pharmaceutical formulations using chloramine-T as oxidizing agent

“…Its use depends mainly on its ability to cause oxidation of diverse functional groups in both acidic and alkaline media. [40][41][42][43] In the literature is described a method in batch for determination of tetracycline with chloramine-T and gallocyanine. The method is indirect and involves the addition of excess CAT of a known concentration in the presence of HCl and the determination of the unreacted CAT by measurement of the decrease in the absorbance of the dye gallocyanine.…”