127-52-6Relevant articles and documents
A Study of Substituent Effect on the Oxidative Strengths of N-Chloroarenesulphonamides: Kinetics of Oxidation of Leucine and Isoleucine in Aqueous Acid Medium
Shetty, Mahesha,Gowda, B. Thimme
, p. 63 - 72 (2004)
To study the variation of oxidative strengths of N-chloro- arenesulphonamides with substitution in the benzene ring, six mono- and five di-substituted N-chloro-arenesulphonamides are employed as oxidants for studying the kinetics of oxidation of two neutral amino acids, L-leucine and L-isoleucine in aqueous acid medium. The N-chloro-arenesulphonamides studied are of the constitution: ArSO2NaNCl·H2O (where Ar = C6H5, 4-CH3C6H4, 4-C2H5C6H4, 4-FC6H 4, 4-ClC6H4, 4-BrC6H4, 2,3-(CH3)2C6H3, 2,4-(CH 3)2C6H3, 2-CH3-4-Cl 2C6H3, 2,4-Cl2C6H 3, and 3,4-Cl2C6H3). The reactions show second order kinetics in [oxidant], fractional order in [amino acid] and inverse dependence on [H+]. Addition of the reduced product of the oxidants or variation in ionic strength of the medium has no significant effect on the rates of oxidations. A two-pathway mechanism is considered to explain the experimental results. Effective oxidizing species of the oxidants is Cl + in different forms. Therefore the oxidising strengths of N-chloro-arenesulphonamides depend on the ease with which Cl+ is released from them. The study reveals that the introduction of substituent in the benzene ring of the oxidant affects both the kinetic and thermodynamic data for the oxidations The electron releasing groups such as CH3 generally inhibit the rates, while electron-withdrawing groups such as Cl enhance this ability, as the electron withdrawing groups ease the release of Cl+ from the reagents and hence increase the oxidising strengths. The on Ea and log A and validity of the Hammett and isokinetic relationships for the oxidations are also analysed.
KINETICS AND MECHANISM OF THE OXIDATION OF SOME HEXOSES BY SODIUM N-CHLOROBENZENESULPHONAMIDE IN THE PRESENCE OF SODIUM HYDROXIDE
Iyengar, Tirumala A.,Puttaswamy,Mahadevappa, Dandinasivara S.
, p. 119 - 130 (1990)
The kinetics of the oxidation of D-glucose, D-mannose, D-galactose and D-fructose by sodium N-chlorobenzenesulphonamide or Chloramine-B (CAB) in the presence of alkali at 35 deg C has been investigated, and the rate = k was observed.The product, benzenesulphonamide, had no influence, increase of ionic strength increased the rate, and the rate decreased when the dielectric constant of the medium was decreased.The proton inventory was studied for the reactions in H2O-D2O mixtures.The rates increased in the order D-fructose > D-galactose > D-glucose > D-mannose.An isokinetic relation was observed with β 347 K, which showed the reaction to be enthalpy-controlled.
SULFONAMIDE ANALOGUES OF GALIELLALACTONE
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Page/Page column 40; 41, (2018/06/30)
Disclosed are sulfonamide analogues of galiellactone of formula (I) as STAT3-inhibitors for use in the treatment of a STAT3 signaling related disorder, e.g. solid cancers, hematological cancers, benign tumors, hyperproliferative diseases, inflammations, autoimmune diseases, graft or transplant rejections, delayed physiological function of grafts or transplants, neurodegenerative diseases and viral infections. The sulfonamide comprises a cyclic substituent.
The efficient palladium-catalyzed selective t synthesis of benzenesulfonic acids
Jagadeesh, Rajenahally V.,Sandhya, Y. Sree,Karthikeyan,Reddy, S. Sudhakar,Reddy, P. Pradeep Kumar,Kumar, M. Viniod,Charan, K. T. Prabhu,Narender,Bhagat
experimental part, p. 2343 - 2349 (2011/09/12)
Palladium-catalyzed synthetic methodology has been developed for the synthesis of 2-aminobenzenesulfonic acids from benzothiazoles in good to excellent yields using chloramine-B in alkaline (pH 12) acetonitrile/water (1:1) at 80C.
Kinetics and mechanism of oxidation of D-fructose and D-glucose by sodium salts of N-(chloro)-mono/di-substituted benzenesulfonamides in aqueous alkaline medium
Gowda, B. Thimme,Damodara,Jyothi
, p. 572 - 582 (2007/10/03)
In an effort to introduce N-chloroarylsulfonamides of different oxidizing strengths, nine sodium salts of mono- and di-substituted N- chloroarylsulfonamides are employed as oxidants for studying the kinetics of oxidation of D-fructose and D-glucose in aqueous alkaline medium. The results are analyzed along with those by the sodium salts of N-chlorobenzenesulfonamide and N-chloro-4-methylbenzenesulfonamide. The reactions show first-order kinetics each in [oxidant], [Fru/Glu], and [OH-]. The rates slightly increase with increase in ionic strength of the medium. Further, the rate of oxidation of fructose is higher by 4 to 5 times than that of the glucose oxidation, by the same oxidant. Similarly, Ea values for glucose oxidations are higher by about 1.5 times the Ea values for fructose oxidations. The results have been explained by a plausible mechanism, and the related rate law deduced. The significant changes in the kinetics and thermodynamic data are observed with change of substituent in the benzene ring. It is because Cl + is the effective oxidizing species in the reactions of N-chloroarylsulfonamides. The oxidative strengths of the latter therefore depend on the ease with which Cl+ is released from them. The ease with which Cl+ is released from N-chloroarylsulfonamides depends on the electron density of the nitrogen atom of the sulfonamide group, which in turn depends on the nature of the substituent in the benzene ring. The following Hammett equations are valid for the oxidation of fructose and glucose, log kobs = -3.13 + 0.54 σ ρ and log kobs = -3.81 + 0.28 σ ρ, respectively. The enthalpies and entropies of activations for oxidations by all the N-chloroarylsulfonamides correlate well with isokinetic temperatures of 301 K and 299 K, for fructose and glucose oxidations, respectively. The effect of substitution in the oxidants on the Ea and log A for the oxidations is also considered.
Mechanistic investigations of oxidation of substituted ethanols by N-sodio-W-chlorobenzenesulfonamide in acid medium
Puttaswamy
, p. 438 - 441 (2007/10/03)
The oxidation kinetics of ethanol and substituted ethanols, RCH2CH2OH (where R = H, OC2H5, OCH3, NH2, Cl and Br) by N-sodio-N-chlorobenzenesulfonamide or chloramine-B (CAB) in the presence of HCl have been studied at 318 K. The rates show first order dependence on [CAB] and fractional order each on [alcohol], [H+] and [Cl-]. Variations of ionic strength and dielectric constant of the medium and addition of reaction product (benzenesulfonamide) have no effect on the rate. Activation parameters have been calculated. The solvent isotope effect has been studied in D2O medium. Michaelis-Menten type of kinetics is observed. Mechanisms proposed are consistent with the experimental rate laws.
Oxidation of erythrose series sugars by sodium N-chlorobenzenesulphonamide in alkaline medium : A kinetic study
Raghavendra,Rangappa,Mahadevappa,Channe Gowda
, p. 783 - 792 (2007/10/03)
The kinetics of oxidation of D-glucose, D-mannose, D-fructose, D-arabinose, and D-ribose, with sodium N-chlorobenzenesulphonamide (chloramine-B or CAB) in alkaline medium have been studied at 35°C and the rate law, rate = κ′ [CAB] [Sugar] [OH-]2 is observed. The rate of reaction is influenced by a change in ionic strength of the medium, and the dielectric effect is negative. The solvent isotope studies in D2O show that the rate is almost doubled in heavy water. HPLC and GLC-MS analyses of the products indicated that the erythrose-series sugars are oxidized to a mixture of aldonic acids consisting of arabinonic, ribonic, erythronic, and glyceric acids in varying proportions. Based on these data, a mechanism involving the aldoenolic anions of pentoses and keto-enolic anions of hexoses is suggested.
Kinetics and Mechanism of Oxidation of Substituted Mandelic Acids by Sodium N-chlorobenzenesulphonamide
Jain, Anandi L.,Banerji, Kalyan K.
, p. 654 - 656 (2007/10/02)
The oxidation of mandelic acid and nine monosubstituted mandelic acids by sodium N-chlorobenzenesulphonamide has been studied in aqueous acetic acid and perchloric acid.The reaction is of first order with respect to the concentrations of the oxidant, the hydroxy acid and hydrogen ions.The primary kinetic isotope effect (kH/kD) is 5,11 +/- 0.06 at 303 K.The solvent isotope effect is 0.406 at 303 K.The reaction exhibits a reaction constant p+ = -2.13 at 303 K.PhSO2NHCl has been postulated as the active oxidising species.The rates were determined at four temperatures and the activation parameters were evaluated.A mechanism involving transfer of a hydride ion to the oxidant has been suggested.
Sodium N-Chlorobenzenesulphonamide (Chloramine-B) as an Analytical Reagent : Estimation of Thiosemicarbazide Alone and in its Metal Complexes
Mahadevappa, D. S.,Rangappa, K. S.,Gowda, B. T.
, p. 102 - 103 (2007/10/02)
A simple, rapid and accurate method for the estimation of thiosemicarbazide (TSC) alone and in its metal complexes (with Zn, Cd, Hg, Ni, Pt and Pd) in aqueous medium by back titration with sodium N-chlorobenzenesulphonamide (chloramine-B) has been developed.The oxidation involves a twelve-electron stoichiometry per TSC molecule in aqueous medium of pH 2-7 and in the presence of 0.1N mineral acids.The proposed analytical method is useful for the rapid estimation of the ligand on a macroscale and also for computing the number of ligand molecules in a TSC-metal complex.
