Molecular Diversity

, Volume 20, Issue 2, pp 379–390 | Cite as

A facile, regioselective synthesis of novel 3-(N-phenylcarboxamide)pyrazolo[1,5-a]pyrimidine analogs in the presence of KHSO\(_{4}\) in aqueous media assisted by ultrasound and their antibacterial activities

  • Shunan Kaping
  • Ivee Boiss
  • Laishram Indira Singha
  • Philippe Helissey
  • Jai N. Vishwakarma
Full-Length Paper


An environmentally benign, simple, efficient, and convenient route is described for the synthesis of novel pyrazolo[1,5-a]pyrimidine derivatives under ultrasound irradiation. Condensation of aminopyrazole 5 with formylated active proton compounds (6, 8, E–G, 12, and 15) furnished pyrazolopyrimidine (7910, 13, and 16) in high-to-excellent yields. In comparison with conventional methods, ultrasound irradiation offers several advantages, such as shorter reaction time, higher yields, milder conditions, and environmental friendliness. The reaction is clean with excellent yields and reduces the use of solvents. X-ray crystallographic study of compound 7c confirmed the regioselectivity of the reaction. The antibacterial profile of the newly synthesized compounds was evaluated by cup and saucer method.


Pyrazolopyrimidines 5-Aminopyrazoles Condensation Formylation Antibacterial Ultrasound irradiation X-ray crystallography 



The authors wish to thank Rev. Fr. Dr. Stephen Mavely, Vice Chancellor, Assam Don Bosco University for providing infrastructure for the execution of this work. The authors also wish to express their gratitude to the IIT, Guwahati; Tezpur University, Tezpur; SAIF-NEHU, Shillong; and SAIF-CDRI, Lucknow. Our thanks are also due to the Department of Biotechnology (DBT), Government of India for a research Grant. SK thanks NER-BPMC-DBT, New Delhi for the award of a research fellowship.

Supplementary material

11030_2015_9639_MOESM1_ESM.cif (16 kb)
CIF files for compound 7c 17 KB
11030_2015_9639_MOESM2_ESM.pdf (1.8 mb)
1H NMR, 13C NM Mass Spectra 1855 KB


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Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  • Shunan Kaping
    • 1
  • Ivee Boiss
    • 3
  • Laishram Indira Singha
    • 3
  • Philippe Helissey
    • 2
  • Jai N. Vishwakarma
    • 1
  1. 1.Organic Research Laboratory, Department of Chemical ScienceAssam Don Bosco UniversityGuwahatiIndia
  2. 2.Laboratoire de Chimie Thérapeutique, UMR CNRS No. 8638, Université Paris Descartes, Faculte des Sciences Pharmaceutiques et BiologiquesParis Cedex 06France
  3. 3.Department of BiotechnologySt. Anthonys CollegeShillongIndia

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