Synthesis of pyrazol-4-carbonitriles by thermal dehydratation of pyrazol-4-carbaldehyde oximes

Authors

  • M. K. Bratenko Bukovinian State Medical University, Ukraine
  • N. V. Panasenko Bukovinian State Medical University, Ukraine
  • M. V. Vovk Institute of Organic Chemistry of the NAS of Ukraine, Ukraine

DOI:

https://doi.org/10.24959/ophcj.13.735

Keywords:

pyrazol-4-carbaldehyde oximes, 4-pyrazolcarboxylic acids nitriles, thermal dehydratation, dimethylformamide

Abstract

A detailed literary analysis of the methods for synthesis, chemical and biological properties of 4-pyrazolcarboxylic acids nitriles, which are important synthetic building-blocks for purposeful obtaining of functional derivatives of pyrazole, has been conducted. A simple and effective method of obtaining of synthetically and pharmacologically perspective nitriles of 4-pyrazolecarboxylic acids has been developed. They are obtained by thermal dehydratation of oximes of easily available pyrazole-4-carbaldehydes in dimethylformamide. It has been determined that heating of these compounds in the boiling dimethylformamide for 3 hours is enough to produce pyrazole-4-carbonitriles with 56-86% yields. It has also been found that in comparison with aliphatic and aromatic aldoximes increase of the temperature of the reaction medium till it boils (by 17°C) in case of oximes of pyrazole-4-carbaldehydes allows to reduce 16 times the reaction time, thus making this synthesis to be economically effective and technological. It has been shown that in this transformation DMFA simultaneously plays roles of the solvent and reagent. The mechanism of the dehydratation discovered has been proposed. It includes consecutive elimination of dimethylamine and formate acid from the intermediate generated by nucleophilic addition of oximic hydroxyl to the electrophilic centre of dimethylformamide. The composition and structure of the nitriles synthesized have been confirmed by elemental analysis, chromatomass-spectrometry, IR- and 1H NMR spectroscopy.

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References

  1. Prakash O., Pundeer R., Ranjan P. et al. // Ind. J. Chem. B. – 2009. – Vol. 48. – P. 503-568.
  2. Kumar R., Nair R.R., Dhima S.S. et al. // J. Het. Chem. – 2011. – Vol. 48. – P. 1211-1215.
  3. Bekhit A.A., Ashour H.M.A., Bekhit A.E. et al. // J. Enzyme Inhibit. Med. Chem. – 2009. – Vol. 24. – P. 296-309.
  4. Sharma P.K., Chanda K.N., Kumar P. et al. // Eur. J. Med. Chem. – 2011. – Vol. 46. – P. 1425-1432.
  5. Bekhit A.A., Fahmy H.T.Y., Roston S.A.F. et al. // Eur. J. Med. Chem. – 2010. – Vol. 45. – P. 6027-6038.
  6. Goddard C.J. // J. Het. Chem. – 1991. – Vol. 28. – P. 1607-1612.
  7. Reddy G.J., Manjula D., Rao K.S. // Ind. J. Chem. B. – 2005. – Vol. 44. – P. 2412-2415.
  8. Saliman S.A., Abdelhamid J.A., Gaber H.M. // J. Het. Chem. – 2005. – Vol. 42. – P. 1185-1189.
  9. Hassaneen H.M., Ead H.A., Elwan N.M., Shawal A.S. // Heterocycles. – 1988. – Vol. 27. – P. 2857-2862.
  10. Reddy G.J., Sailaja J., Pallavi K., Rao K.S. // Ind. J. Chem. B. – 2005. – Vol. 44. – P. 180-183.
  11. Вовк М.В., Братенко М.К., Чорноус В.О. 4-Функціональнозаміщені піразоли. – Чернівці: Прут, 2008. – С. 287.
  12. Suspana P., Liashopalos T., Tsangos P.G., Varvounis G. // Synlett. – 2007. – №17. – P. 2671-2674.
  13. Prakash O., Pannu K., Naithani R., Kaur H. // Synt. Commun. – 2006. – Vol. 36. – P. 3479-3485.

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Published

2013-09-10

How to Cite

(1)
Bratenko, M. K.; Panasenko, N. V.; Vovk, M. V. Synthesis of Pyrazol-4-Carbonitriles by Thermal Dehydratation of Pyrazol-4-Carbaldehyde Oximes. J. Org. Pharm. Chem. 2013, 11, 22-25.

Issue

Vol. 11 No. 3(43) (2013)

Section

Original Researches

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Copyright (c) 2013 National University of Pharmacy

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