Archives of Pharmacal Research

, 16:180 | Cite as

Temperature, medium and structural effects on the acid dissociation constants of certain Schiff bases derived from isatin with some amino acids and aroylhydrazines

  • Aly M. A. Hassaan
  • M. T. A. Quenawy
Research Articles


The acid dissociatioin constants of certain Schiff bases derived from isatin with p-substituted benzoyl hydrazines and somee amino acids of glycine, β- and α-alanine, valine, β-phenyl-α-alanine and anthranilic acid have been determined potentiometrically at different temperatures in different aquo-organic solvent mixtures (ethanol, dioxane, ddimethyl formamide, methanol, acetone and tetrahydrofurance). The pKa values were demonstrated on the light of the different electronic and steric effects of the substituents and the solvent characteristics. In all the mixed media used, ionization of the compounds decreased by increasing the mole fraction of the organic cosolvent. Theermodynamic parameters (ΔH°, ΔG°, ΔS°) were evaluated. The structural effects of the investigated compounds on these parameters were reported and discussed.

Key words

Isatin Amino acids Aroylhydrazies Dissociation constants 

References Cited

  1. Abu El-Reash, G. M., Taha, F., Shallaby, A. M. and El-Gamal, O. A., Synthesis and characterization of metal complexes with a Schiff formed by condensation of S-benzyldithiocarbazate with isatin.Indian J. Chem., 30A, 286–289 (1991).Google Scholar
  2. Bauer, D. J. and Sadler, P. W., Derivatives of isatin betathiosemicarbazone with anti-viral chemotherapeutic activity against ectromelia infection, 190, 1167–1169 (1961).Google Scholar
  3. Bayliss, N. S. and Mcrae, E. G., Theory of solvent effects on molecular electronic spectra. Frequency Shifts.J. Phys. Chem., 61, 562–572 (1957)CrossRefGoogle Scholar
  4. Bhardwaj, S., Ansari, M. N. and Jain, M. C., Synthesis and characterization of Some 3d metal complexes with isatin hydrazones.Indian J. Chem., 28A, 81–82 (1989).Google Scholar
  5. Coetzee, J. F. and Ritchie, C. D., Solutesolvent interactions, Macel Dekker Ltd., New York, London 211, 222 (1969).Google Scholar
  6. Douheret, G., Potentiels de jonction liquide et effect de millieu en solvants mixtes eau-solvent a protique dipolaire. Application à 1’étalonnage dans ces mélanges du systéme d’électrodes verrecalomel. Properiétés diélectriques de ces milieux.Bull. Soc. Chem. Fr., 3122–3131 (1968).Google Scholar
  7. Denison, J. T. and Ramsey, J. B., The free energy, enthalpy and entropy of dissociation of some perchlorates in ethylene chloride and ethylidene chloride.J. Am. Chem. Soc., 77, 2615–2621 (1955).CrossRefGoogle Scholar
  8. Douheret, G., Étude de la dissociation de composés organiques en en milieux hydro-organiques. 1-Détermination du potentiel de jonction liquide et de l’effect de milieu sur 1’ion hydrogène dans ces systémmes, et étude de la disscoiation de quelques couples acids-bases.Bull. Soc. Chem. Fr., 1412–1419 (1967).Google Scholar
  9. Franks, F. and Ives, D. J. G., The structural properties of alcohol-wawter mixtures.Quart. Rev., 20, 1–44 (1966).CrossRefGoogle Scholar
  10. Gilkerson, W. R., Application of free volume theory to ion pair dissociation constant.J. Chem. Phys., 25, 1199–1202 (1956).CrossRefGoogle Scholar
  11. Hassaan, A. M. A., Soliman, E. M. and El-Shabasy, M., Complexes of isatin-amino acid Schiff bases with Fe (III), Fe(II), Co(II), Ni(II) and Cu(II), 19, 773–778 (1989).Google Scholar
  12. Hassaan, A. M. A., Nickel(II) chelates of Schiff bases derived from isatin and chromone with amino acids and substituted hydrazines, 15, 283–285 (1990).Google Scholar
  13. Hassaan, A. M. A. and Soliman, E. M., Ni(II) and Cu(II) complexes of Schiff bases derived from isatin with some amino acids.International J. Chem., 2, 119–123 (1991).Google Scholar
  14. Holzbecher, Z., 3-Semicarbazones and 3(3-thiosemicarbazones) of isatin and its derivatives.Chem. Listy 44, 126–127 (1950).Google Scholar
  15. Irving, H. and Rossotti, H. S., Methods for computing successive stability constants from experimental formation curves.J. Chem. Soc., 3397–3405 (1953).Google Scholar
  16. Khulb, R. C., Bhoom, Y. K. and Singh, R. P., Copper (II) and nickel (II) complexes of isatin-3,2-quinolylhydrazones.J. Indian Chem. Soc., 58, 840–843 (1981).Google Scholar
  17. Knotz, F., Manufacture of antiviral and antimicrobial substances. 5.1-Isatinyl methyl derivatives of NH-acidic compounds.Sci. Pharm., 41, 123–129 (1973).Google Scholar
  18. Ledger, M. B. and Suppan, P., Spectroscopic studies of electron distribution.Spectrochim. Acta 23A, 641–653 (1967).Google Scholar
  19. Mambsch, E., Isatins and selective herbicides.German Patent, 1, 459–461 (1957).Google Scholar
  20. Masoud, M. S., Aly, S. A., Aly, G. Y. and El-Dessouky, M. A., Substituent effect on the dissociation constants and the strength of the hydrogen bond in some azocresol compounds.J. Chem. Eng. Dat, 28, 297–300 (1983).CrossRefGoogle Scholar
  21. Mahmoud, M. R., El-Roudi, A., Abdel Gaber, A. and Abd Alla, E. M., Medium effect on the second dissociation constant of amino acids.Annali di Chimica, 78, 461–471 (1988).Google Scholar
  22. Mui, K. K., McBryde, A. W. and Nieboer, E., The stability of some metal complexes in mixed solvents.Can. J. Chem., 52, 1821–1833 (1974).CrossRefGoogle Scholar
  23. Snavely, F. A. and Sun Un, A study of the structure of hydrazones of Indol-2,3-dione and 1-Methyl-indole-2,3-dione with nuclear magnetic resonance spectroscopy.J. Org. Chem., 46, 2764–2766Google Scholar
  24. Singh, K., Singh, G. and Dgupta, V., Stabilities and thermodynamic functions of the complexes of dimethyltin (IV) ion with some acids.Indian J. Chem., 27A, 264–266 (1988).Google Scholar
  25. Tacconi, G., Righetti, P. P. und Desimoni, G., Einfache Darstellung von N-substituierten Isatinen.J. Prakt. Chemie, 315, 319–344 (1973).CrossRefGoogle Scholar
  26. Varma, R. S. and Nobels, W. L., Antiviral, antibacterial, and antifungal activities of isatin N-Mannich bases.J. Pharm. Sci., 64, 881–882 (1975).PubMedCrossRefGoogle Scholar
  27. Varma, R. S. and Khan, I. A., synthesis of 3-arylamino-2-indolinones as excystment and cysticidal agents against Schizopyrenus russelli.Indian J. Med. Res., 67, 315–320 (1978).PubMedGoogle Scholar

Copyright information

© The Pharmaceutical Society of Korea 1993

Authors and Affiliations

  • Aly M. A. Hassaan
    • 1
  • M. T. A. Quenawy
    • 1
  1. 1.Chemistry Depreatment, Faculty of ScienceMinia UniversityEl-MiniaEgypt

Personalised recommendations