Mechanistic investigation of oxidation of metronidazole and tinidazole with N-bromosuccinimide in acid medium: A kinetic approach

Abstract

Metronidazole (MTZ) and tinidazole (TNZ) belong to nitroimidazole group of drugs used to treat infections such as ameobiasis, giardiasis and trichomoniasis. The kinetics of oxidation of MTZ and TNZ with N-bromosuccinimide (NBS) in perchloric acid medium has been investigated at 308 K. A 1:1 stoichiometry has been observed in both MTZ and TNZ cases. The oxidation reactions of both MTZ and TNZ follow the same rate law, -d[NBS]/dt = [NBS][Sub][H + ]. However, in case of MTZ, at higher concentrations of H + (0.006-0.01 mol dm -3 ), the rate law obtained is -d[NBS]/dt = [NBS][MTZ][H + ] -1 . Accelerating effect of [Cl -] and retardation of the added succinimide on the reaction rate have been observed in the case of MTZ. The reactions were examined with reference to changes in concentration of added neutral salt, ionic strength and dielectric permittivity of the medium. The overall activation parameters have been evaluated from the Arrhenius plot. The reactive oxidizing species of NBS have been determined. The main oxidation products were identified by IR and 1 H NMR spectral analyses. The observed results have been explained by plausible mechanisms and the relative rate laws have been deduced.

Kinetics of oxidation of d(+)melibiose and cellobiose by N-bromoacetamide using a rhodium(III) chloride catalyst

“…Various N-halogeno compounds [1][2][3][4][5][6][7], such as Nbromoacetamide (NBA), N-bromosuccinimide (NBS), N-chlorosuccinimide (NCS) are reported to have diverse chemistry due to their ability to act as a source of halonium cations, hypohalite species, nitrogen anions, strong electrolytes in aqueous solution and strongly polarised N-linked halogens. NBA has been used as an oxidant for uncatalysed [8][9][10][11][12] and catalysed [13][14][15][16][17][18] reactions involving transition metals including Ru(III), Ir(III) and Pd(II) as homogeneous catalysts.…”

Ruthenium (III)-catalyzed oxidative cleavage of phenylpropanolamine with N-bromosuccinimide in hydrochloric acid medium: a kinetic and mechanistic approach

“…This potent oxidizing agent has been extensively used in the determination of a number of pharmaceutical compounds [8][9][10][11]. However, little information is available in the literature on NBS reactions, particularly with respect to the oxidation kinetics of bio-active compounds [12][13][14]. In view of these facts, it was felt important and interesting to investigate the oxidative behavior of NBS towards PPA.…”

A Kinetic and Mechanistic Study on The Oxidation of 3-Carboxy-3-Hydroxy Pentanedioic Acid in Buffered Medium

“…The kinetics of oxidation of amino alcohols by NBS in an alkaline medium have been studied . Oxidative cleavage of gabapentin, metronidazole, and tinidazole by N-bromosuccinimide in an acid medium has been investigated. , Oxidative deprotection of THP ethers had been done effectively with NBS in the presence of β-cyclodextrin . The kinetics and mechanism of oxidation of 4-oxo acids by NBS in an aqueous acetic acid medium and oxidation of some amino acids in an acidic medium have been studied. , …”