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Molecular Diversity

, Volume 17, Issue 4, pp 731–743 | Cite as

Parallel synthesis of 7-heteroaryl-pyrazolo[1,5-a]pyrimidine-3-carboxamides

  • Sizana Ahmetaj
  • Nina Velikanje
  • Uroš Grošelj
  • Ines Šterbal
  • Benjamin Prek
  • Amalija Golobič
  • Drago Kočar
  • Georg Dahmann
  • Branko Stanovnik
  • Jurij SveteEmail author
Full-Length Paper

Abstract

A simple and practical four-step protocol for the parallel synthesis of 7-heteroaryl-pyrazolo[1,5-\(a\)]pyrimidine-3-carboxamides was developed. The synthesis starts with transformation of commercially available 2-acetylpyridine and acetylpyrazine with \(N,\) \(N\)-dimethylformamide dimethylacetal into the corresponding \((E)\)-3-(dimethylamino)-1-(heteroaryl)prop-2-en-1-ones followed by cyclisation with methyl 5-amino-1\(H\)-pyrazole-4-carboxylate to give methyl 7-heteroarylpyrazolo[1,5-\(a\)]pyrimidine-3-carboxylates. Hydrolysis of the ester group and subsequent amidation of the so formed carboxylic acids with 12 primary and secondary aliphatic amines furnished a library of 24 title compounds in good overall yields and purity.

Keywords

Pyrazolo[1\(, \)5-a]pyrimidines  Enamino ketones Cyclisation Parallel synthesis Pyridines Pyrazines 

Notes

Acknowledgments

The financial support from Boehringer-Ingelheim Pharma (Biberach, Germany) and from the Slovenian Research Agency through grant P1-0179 is gratefully acknowledged. We also thank EN-FIST Centre of Excellence (Ljubljana, Slovenia) for using SuperNova diffractometer.

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Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • Sizana Ahmetaj
    • 1
  • Nina Velikanje
    • 1
  • Uroš Grošelj
    • 1
  • Ines Šterbal
    • 1
  • Benjamin Prek
    • 1
  • Amalija Golobič
    • 1
  • Drago Kočar
    • 1
  • Georg Dahmann
    • 2
  • Branko Stanovnik
    • 1
  • Jurij Svete
    • 1
    Email author
  1. 1.Faculty of Chemistry and Chemical TechnologyUniversity of LjubljanaLjubljanaSlovenia
  2. 2.Medicinal ChemistryBoehringer Ingelheim Pharma GmbH & Co. KGBiberachGermany

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