Determination of keto–enol equilibrium constants and the kinetic study of the nitrosation reaction of β-dicarbonyl compounds

(Note: The full text of this document is currently only available in the PDF Version )

Emilia Iglesias


Abstract

The keno–enol equilibrium constants of acetylacetone, ethyl acetoacetate and ethyl benzoylacetate in water at 25 °C are determined by studying the influence of surfactants on their UV–VIS spectra, following the method applied to benzoylacetone published recently. These measured equilibrium constants are used to obtain the reactivity of the ketones towards several nitrosating agents. For this end, the nitrosation reaction of benzoylacetone, acetylacetone, ethyl acetoacetate and ethyl benzoylacetate are studied in aqueous acidic solution in the presence and absence of Cl-, Br- or SCN-. Analysis of the kinetic data indicates that the rate-limiting step is, in every case, the reaction of the enol.


References

  1. O. Touster, Organic Reactions, Wiley, New York, 1953, vol. 7, ch. 6 Search PubMed.
  2. J. R. Leis, M. E. Peña and D. L. H. Williams, J. Chem. Soc., Chem. Commun., 1987, 45 RSC.
  3. J. R. Leis, M. E. Peña, D. L. H. Williams and S. D. Mawson, J. Chem. Soc., Perkin Trans. 2, 1988, 157 RSC.
  4. (a) P. Roy and D. L. H. Williams, J. Chem. Res. (S), 1988, 122 Search PubMed; (b) M. A. C. Reed and D. L. H. Williams, J. Chem. Res. (S), 1993, 342 Search PubMed.
  5. P. Hervés-Beloso, P. Roy and D. L. H. Williams, J. Chem. Soc., Perkin Trans. 2, 1991, 17 RSC.
  6. E. Iglesias and D. L. H. Williams, J. Chem. Soc., Perkin Trans. 2, 1989, 343 RSC.
  7. E. Iglesias, J. Chem. Res. (S), 1995, 98 Search PubMed.
  8. D. L. H. Williams, Nitrosation, Cambridge University Press, Cambridge, 1988 Search PubMed.
  9. (a) J. Toullec, in The Chemistry of Enols, ed. Z. Rappoport, Wiley, Chichester, England, 1990, pp. 323–398 Search PubMed; (b) J. Toullec, Adv. Phys. Org. Chem., 1982, 18, 1 CAS.
  10. S. Forsén and M. Nilson, in The Chemistry of the Carbonyl Group, ed. J. Zabicky, Interscience, London, 1970, pp. 157–240 Search PubMed.
  11. E. J. Fendler and J. H. Fendler, Catalysis in Micellar and Macromolecular Systems, Academic Press, New York, 1975 Search PubMed.
  12. C. A. Bunton and G. Savelli, Adv. Phys. Org. Chem., 1986, 22, 231.
  13. E. Iglesias, J. Phys. Chem., 1996, 100, 12 592 CrossRef CAS.
  14. J. N. Spencer, E. S. Holmboe, M. R. Kirshenbaum, D. W. Firth and P. B. Pinto, Can. J. Chem., 1982, 60, 1178 CAS.
  15. (a) S. G. Mills and P. Beak, J. Org. Chem., 1985, 50, 1216 CrossRef CAS; (b) M. Moriyasu, A. Kato and Y. Hashimoto, J. Chem. Soc., Perkin Trans. 2, 1986, 515 RSC.
  16. A. S. N. Murthy, A. Balasubramanian and C. N. R. Rao, Can. J. Chem., 1962, 40, 2267.
  17. R. A. Morton, A. Hassan and T. C. Calloway, J. Chem. Soc., 1934, 883 RSC.
  18. E. J. Drexler and K. W. Field, J. Chem. Educ., 1976, 53, 392 CAS.
  19. A. Gero, J. Org. Chem., 1954, 19, 469 CrossRef CAS.
  20. J. L. Burdett and M. T. Rogers, J. Am. Chem. Soc., 1964, 86, 2105 CrossRef CAS.
  21. A. Yogev and Y. Mazur, J. Org. Chem., 1967, 32, 2162 CrossRef CAS.
  22. J. H. Ridd, Adv. Phys. Org. Chem., 1978, 16, 1 CAS and references therein.
  23. J. Tummavouri and P. Lumme, Acta Chem. Scand., 1965, 19, 617 CrossRef; 1968, 22, 2003.
  24. H. Schmid and E. Hallaba, Monatsh., 1956, 87, 560 Search PubMed.
  25. H. Schmid and E. Fouad, Monatsh., 1957, 88, 631 Search PubMed.
  26. G. Stedman and P. A. E. Whincup, J. Chem. Soc., 1963, 5796 RSC.
  27. (a) L. R. Dix and D. L. H. Williams, J. Chem. Res., 1984, 96 Search PubMed; (b) A. Castro, E. Iglesias, J. R. Leis and M. E. Peña, Ber. Bunsenges. Phys. Chem., 1986, 90, 861 Search PubMed.
  28. E. Iglesias and D. L. H. Williams, J. Chem. Soc., Perkin Trans. 2, 1988, 1035 RSC.
  29. D. L. H. Williams, Adv. Phys. Org. Chem., 1983, 19, 381 CAS.
  30. A. Castro, E. Iglesias, J. R. Leis, M. Mosquera and M. E. Peña, Bull. Soc. Chim. Fr., 1987, 83 CAS.
Click here to see how this site uses Cookies. View our privacy policy here.