Mechanistic investigations of oxidation of isatins by sodium N-chlorobenzenesulfonamide in alkaline medium: A kinetic study
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Oxidation of isatins (isatin, 5-methylisatin, 5-bromoisatin and 5-nitroisatin) to their anthranilic acids was performed efficiently with sodium N-chlorobenzenesulfonamide or chloramine-B (CAB) in alkaline medium at 35±0.1°C. The reactions follow identical kinetics for all the isatins, being first-order dependence each in [CAB]o and [Isatin]o and inverse fractional-order on [NaOH]. Addition of halide ions and benzenesulfonamide, reduction product of CAB, do not significantly affect the rate. Variation of ionic strength of the medium had no effect on the rate, while the dielectric effect is negative. The solvent isotope effect was studied using D2O. Activation parameters for the overall reaction have been computed. The rates satisfactorily correlate with the Hammett σ relationship and the reaction constant ρ is −0.31 signifies that electron releasing groups accelerate the reaction while the electron withdrawing groups retard the rate. Values of ΔH≠ and ΔS≠ are linearly related and an isokinetic relationship is observed with β=376 K, indicating the reaction is controlled by enthalpy. The stoichiometry of the title reaction is found to be 1∶1. Oxidation products of isatins were identified as their corresponding anthranilic acids and the yields were found to be around 90 %. The observed results have been explained by a plausible mechanism and the related rate law deduced. This method offers several advantages including high yield of the products, short reaction times, easier isolation of products, and stable, cost effective and relatively non-toxic reagents, which make the reaction process simple and smooth.
1 - 9 - 2005
1 - 9 - 2005
- Department of Post-Graduate Studies in Chemistry, Central College Campus, Bangalore University, 560 001, Bangalore, India, firstname.lastname@example.org
- Department of Post-Graduate Studies in Chemistry, Central College Campus, Bangalore University, 560 001, Bangalore, India
-  J.F.M. da Silva, S.J. Garden and A.C. Pinto: “The chemistry of isatins: a review from 1975–1999”, J. Braz. Chem. Soc., Vol. 12(3), (2001), pp. 273–324 and references therein. http://dx.doi.org/10.1590/S0103-50532001000300002[Crossref]
-  E. Bishop and V.J. Jennings: “Titrimetric analysis with chloramine-T: The status of chloramine-T as a titrimetric reagent”, Talanta, Vol. 1, (1958), pp. 197–199. http://dx.doi.org/10.1016/0039-9140(58)80034-X[Crossref]
-  J.C. Morris, J.R. Salazar and M.A. Winemann: “Equilibrium studies on chloro compounds: the ionization constant of N-chloro-p-toluenesulfonamide”, J. Am. Chem. Soc., Vol. 70, (1948), pp. 2036–2041. http://dx.doi.org/10.1021/ja01186a016[Crossref]
-  T. Higuchi and A. Hussain: “Mechanism of chlorination of cresol by chloramine-T, mediation by dichloramine-T”, J. Chem. Soc. B., (1967), pp. 549–552.
-  M.M. Campbell and G. Johnson: “Chloramine-T and related N-halogeno-N-metallo reagents”, Chem. Rev., Vol. 78, (1978), pp. 65–79. http://dx.doi.org/10.1021/cr60311a005[Crossref]
-  K.K. Banerji, B. Jayaram and D.S. Mahadevappa: “Mechanistic aspects of oxidation by N-metallo-N-haloarylsulfonamides”, J. Sci. Ind. Res., Vol. 46, (1987), pp. 65–76.
-  Puttaswamy, T.M. Anuradha, R. Ramachandrappa and N.M.M. Gowda: “Oxidation of isoniazid by N-haloarenesulfonamidates in alkaline medium: a kinetic and mechanistic study”, Int. J. Chem. Kinet, Vol. 32(4), (2000), pp. 221–230. http://dx.doi.org/10.1002/(SICI)1097-4601(2000)32:4<221::AID-KIN4>3.0.CO;2-1[Crossref]
-  F.F. Hardy and J.P. Johnston: “The interactions of N-bromo-N-sodiobenzesulfonamide (bromamine-B) with p-nitrophenoxide ion”, J. Chem. Soc., Perkin Trans. 2, (1973), pp. 742–746. [Crossref]
-  A. Berka, J. Vulterin and J. Zyka: Newer redox titrants, Pergamon Press, Elmsford, New York, 1965, p. 37.
-  S.P. Meenakshisundaram and R. Sockalingam: “Os(VIII)-catalysed oxidation of sulfides by sodium salt of N-chlorobenzenesulfonamide”, J. Mole. Catal A: Chemical., Vol. 160, (2000), pp. 269–275. http://dx.doi.org/10.1016/S1381-1169(00)00261-2[Crossref]
-  Puttaswamy, T.M. Anuradha and K.L. Mahadevappa: “Kinetic analysis of oxidation of dopamine by sodium N-chlorobenzenesulfonamide in perchloric acid medium: a mechanistic approach”, Indian J. Chem. A, Vol. 40, (2001), pp. 514–518.
-  P.G. Stecher (Ed.): The Merck Index, 8th ed., 1968, p. 232.
-  Puttaswamy and D.S. Mahadevappa: “Oxidation of substituted ethanols by sodium-N-bromobenzenesulfonamide: A kinetic study”, J. Phys. Org. Chem., Vol. 2, (1989), p. 660–671. http://dx.doi.org/10.1002/poc.610020809[Crossref]
-  F.G. Mann and B.C. Sounders: Practical organic chemistry, 4th ed., ELBS-Longman, London, 1960, p. 52.
-  A.I. Vogel: Text book of quantitative inorganic analysis, 4th ed., ELBS-Longman, London, 1978, p. 427.
-  G. Akerloff: “Dielectric constants of some organic solvents-water mixture at various temperatures”, J. Am. Chem. Soc., Vol. 54, (1932), p. 4125. http://dx.doi.org/10.1021/ja01350a001[Crossref]
-  K. Higuchi, K. Ikeda and A. Hussain: “Mechanism and thermodynamics of chlorine transfer among organochlorinating agents: reversible disproportionation of chloramine-T”, J. Chem. Soc. B., (1967), pp. 546–549; “Mechanism and thermodynamics of chlorine transfer among organochlorinating agents: autocatalytic pathway between N-chlorosuccinimide and chloramine-T”, (1968), pp. 1031–1036.
-  D.S. Mahadevappa, B.T. Gowda and N.M.M. Gowda: “Kinetics and mechanism of oxidation of thiocynate ion by sodium N-chloro-4-methylbenzenesulfonamide in alkaline medium”, Z. Naturforsch, Vol. 34b, (1979), pp. 52–57.
-  D.S. Mahadevappa, M.B.M. Gowda and K.S. Rangappa: “Oxidation of methionine by sodium N-chlorobenzenesulfonamide in aqueous solution: a kinetic study”, Oxid. Commun., Vol. 7(1–2), (1984), pp. 167–180.
-  D.S. Mahadevappa, K.S. Rangappa, N.M.M. Gowda and B.T. Gowda: “Kinetic and mechanistic study of oxidation of arginine, histidine and threonine in alkaline medium by N- chloro-N-sodio-p-toluenesulfonamide”, Int. J. Chem. Kinet., Vol. 14, (1982), pp. 1183–1197. http://dx.doi.org/10.1002/kin.550141103[Crossref]
-  H.M.K. Naidu, B. Yamuna and D.S. Mahadevappa: “Osmium(VIII)-catalyzed reactions of allyl and crotyl alcohols with chloramine-T, chloramine-B, bromamine-T and bromamine-B: kinetic and mechanism of formation of halohydrins in alkaline medium”, Indian J. Chem., Vol. 26A, (1987), pp. 114–117.
-  S.P. Mushran, M.C. Agrawal and B. Prasad: “Mechanism of oxidation by chloramine-T Part-I oxidation of α-hydroxyacids”, J. Chem Soc. B., (1971), pp. 1712–1714 and references therein.
-  C.J. Collins and N.S. Bowman: Isotope effects in chemical reactions, Van Nostrand-Reinhold, New York, 1970, p. 267.
-  K.B. Wiberg: Physical organic chemistry, Wiley, New York, 1964.
-  S.W. Benson: The foundations of chemical kinetics, McGraw-Hill, New York, 1960.
-  A.A. Frost and R.G. Pearson: Kinetics and mechanism, 2nd ed., Wiley, New York. 1961.
-  K.J. Laidler: Reaction kinetics, Pergamon, New York, 1963.
-  E.S. Amis: Solvent effects on reaction rates and mechanisms, Academic, New York, 1966.
-  S.G. Entelis and R.P. Tiger: Reaction kinetics in the liquid phase, Wiley, New York, 1976.
-  K.J. Laidler: Chemical kinetics, Tata McGraw-Hill, Mumbai, 1965, p. 246.
-  R.D. Gilliom: Introduction to physical organic chemistry, Addison-Wesley, London, 1970, p. 264.
-  O. Exner: “Entropy-enthalpy compensation and anticompensation: solvation and ligand binding”, Chem. Commun., (2000) pp. 1655–1656 and references therein. [Crossref]
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