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Synthesis, Characterization and Biological Evaluation of some Novel Pyrazolo[1,5-a]Pyrimidine Derivatives

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A convenient synthesis of substituted Pyrazolo[1,5-a]pyrimidine was carried out by the reaction of different ketene dithioacetals with different aromatic amine in isopropanol in the presence of potassium carbonate. The newly synthesized compound were characterized by 1H NMR, IR, Mass and screened for their antimicrobial activity against various strains of bacteria and fungi. From the synthesized different NCEs, compounds 8a, 8d and 8e are broad spectrum drug which can inhibit the growth of gram positive, gram negative bacteria and fungi.


International Letters of Chemistry, Physics and Astronomy (Volume 65)
N. M. Thumar et al., "Synthesis, Characterization and Biological Evaluation of some Novel Pyrazolo[1,5-a]Pyrimidine Derivatives", International Letters of Chemistry, Physics and Astronomy, Vol. 65, pp. 11-26, 2016
Online since:
Apr 2016

[1] D. Pansuriya, K. Menpara, N. Kachhadiya, J. Menpara, and K. Ladva, Synthesis, Characterization & Biological evaluation of sulfonamide analogue of Tetrazolo[1, 5-a] pyrimidines, J. Appl. Chem., vol. 3, no. 6, p.2335–2342, (2014).


[3] B. Elion, S. Callahan, H. Nathan, S. Biebek, R. W. Rundles, and G. H. Hikhings, POTENTIATION BY INHIBITION OF DRUG DEGRADATION: 6-SUBSTITUTED PURINES AND XANTHTNE OXIDASE, Biochem. Pharmacol., vol. 12, p.85–93, (1963).

[4] R. A. Earl, R. J. Pugmire, G. R. Revankar, and eroy B. Townsend, A Chemical and Carbon- 13 Nuclear Magnetic Resonance Reinvestigation of the N-Methyl Isomers Obtained by Direct Methylation of 5-Amino-3, 4- dicyanopyrazole and the Synthesis of Certain Pyrazolo[ 3, 4-d]pyrimidines, J. Org. Chem., vol. 40, no. 12, p.1822–1828, (1975).

[5] T. Novinson, B. Bhooshan, T. Okabe, G. R. Revankar, R. K. Robins, K. Senga, and H. R. Wilson, Novel Heterocyclic Nitrofurfural Hydrazones. In Vivo Antitrypanosomal Activity, J. Med. Chem., vol. 19, no. 4, p.512–516, (1976).

[6] K. Senga, T. Novinson, H. R. Wilson, and R. K. Robins, Synthesis and Antischistosomal Activity of Certain Pyrazolo[ 1, 5-a]pyrimidines, J. Med. Chem., vol. 24, p.610–613, (1981).

[7] M. Suzuki, H. Iwasaki, Y. Fujikawa, M. Sakashita, M. Kitaharac, and R. Sakoda, Synthesis and Biological Evaluations of Condensed Pyridine and Condensed Pyrimidine-Based HMG-CoA Reductase Inhibitors, Bioorg. Med. Chem. Lett., vol. 11, p.1285–1288, (2001).

[8] C. Almansa, A. F. de Arriba, F. L. Cavalcanti, L. A. Gomez, A. Miralles, M. Merlos, J. Garcin-Rafanell, and J. Forn, Synthesis and SAR of a New Series of COX-2-Selective Inhibitors : Pyrazolo [ 1 , 5- a ] pyrimidines, J. Med. Chem., vol. 44, p.350–361, (2001).

[9] T. Novinson, R. Hanson, M. K. Dimmitt, L. N. Simon, R. K. Robins, and D. E. O'Brien, 3-Substituted 5, 7-Dimethylpyrazolo[ 1, 5-a]pyrimidines, 3', 5'-Cyclic-AMP Phosphodiesterase Inhibitors, J. Med. Chem., vol. 17, no. 6, p.645–648, (1974).

[10] C. Chen, K. M. Wilcoxen, C. Q. Huang, Y. Xie, J. R. Mccarthy, T. R. Webb, Y. Zhu, J. Saunders, X. Liu, T. Chen, H. Bozigian, and D. E. Grigoriadis, Design of 2, 5-Dimethyl-3-(6-dimethyl-4-methylpyridin-3-yl)-7-dipropylamino- pyrazolo[1, 5-a]pyrimidine (NBI 30775/R121919) and Structure-Activity Relationships of a Series of Potent and Orally Active Corticotropin-Releasing Factor Receptor Antagonists, J. Med. Chem., vol. 47, p.4787–4798, (2004).

[11] C. Q. Huang, K. M. Wilcoxen, D. E. Grigoriadis, J. R. Mccarthy, and C. Chen, Design and synthesis of 3- ( 2-pyridyl ) pyrazolo [ 1 , 5- a ] pyrimidines as potent CRF 1 receptor antagonists, Bioorg. Med. Chem. Lett., vol. 14, p.3943–3947, (2004).

[12] C. Chen, K. M. Wilcoxen, C. Q. Huang, J. R. Mccarthy, T. Chen, and D. E. Grigoriadis, Optimization of 3-phenylpyrazolo [ 1 , 5- a ] pyrimidines as potent corticotropin-releasing factor-1 antagonists with adequate lipophilicity and water solubility, Bioorg. Med. Chem. Lett., vol. 14, p.3669–3673, (2004).

[13] D. J. Wustrow, T. Capiris, R. Rubin, J. A. Knobelsdorf, H. Akunne, M. D. Davis, R. Mackenzie, T. A. Pugsley, K. T. Zoski, T. G. Heffner, and L. D. Wise, PYRAZOLO[1, 5-a]PYRIMIDINE CRF-1 RECEPTOR ANTAGONISTS, Bioorg. Med. Chem. Lett., vol. 8, p.2067–2070, (1998).

[14] S. Selleri, P. Gratteri, C. Costagli, C. Bonaccini, A. Costanzo, F. Melani, G. Guerrini, G. Ciciani, B. Costa, F. Spinetti, and F. Bruni, Insight into 2-phenylpyrazolo[1, 5-a]pyrimidin-3-yl acetamides as peripheral benzodiazepine receptor ligands: Synthesis, biological evaluation and 3D-QSAR investigation, Bioorg. Med. Chem., vol. 13, p.4821–4834, (2005).

[15] S. Selleri, F. Bruni, C. Costagli, A. Costanzo, G. Guerrini, G. Ciciani, and C. Martini, 2-Arylpyrazolo [ 1 , 5- a ] pyrimidin-3-yl Acetamides . New Potent and Selective Peripheral Benzodiazepine Receptor Ligands, Bioorg. Med. Chem., vol. 9, p.2661–2671, (2001).

[16] S. Selleri, F. Bruni, C. Costagli, A. Costanzo, G. Guerrini, G. Ciciani, and C. Martini, Synthesis and BZR Affnity of Pyrazolo [ 1 , 5- a ] pyrimidine Derivatives . Part 1 : Study of the Structural Features for BZR Recognition, Bioorg. Med. Chem., vol. 7, p.2705–2711, (1999).

[17] I. Drizin, M. W. Holladay, L. Yi, H. Q. Zhang, S. Gopalakrishnan, M. Gopalakrishnan, K. L. Whiteaker, S. A. Buckner, J. P. Sullivan, and W. A. Carroll, Structure – Activity Studies for a Novel Series of Tricyclic Dihydropyrimidines as K ATP Channel Openers ( KCOs ), Bioorg. Med. Chem. Lett., vol. 12, p.1481–1484, (2002).

[18] W. A. Foster and C. Jack, US 256309, 1882.

[19] L. J. Phillipson, D. H. Segal, T. L. Nero, M. W. Parker, S. Wan, M. De Silva, M. A. Guthridge, A. H. Wei, and C. J. Burns, Discovery and SAR of novel pyrazolo[1, 5-a]pyrimidines as inhibitors of CDK9, Bioorg. Med. Chem., vol. 23, no. 19, p.6280–6296, (2015).

[20] W. E. Kirkpatrick, T. Okabe, I. W. Hillyard, R. K. Robins, A. T. Dren, and T. Novinson, 3-Halo-5, 7-dimethylpyrazolo[ 1, 5-a]pyrimidines, a Nonbenzodiazepinoid Class of Antianxiety Agents Devoid of Potentiation of Central Nervous System Depressant Effects of Ethanol or Barbiturates, J. Med. Chem., vol. 20, no. 3, p.386–393, (1977).

[21] C. F. P. George, GABA receptors and mechanism of action of hypnotics, Lancet, vol. 358, p.1623–1626, (2001).

[22] S. K. Sullivan, R. E. Petroski, G. Verge, R. S. Gross, A. C. Foster, and D. E. Grigoriadis, Characterization of the Interaction of Indiplon , a Novel Pyrazolopyrimidine Sedative-Hypnotic, with the GABA A Receptor, J. Pharmacol. Exp. Ther., vol. 311, no. 2, p.537–546, (2004).

[23] F. Wegner, W. Deuther-conrad, M. Scheunemann, P. Brust, S. Fischer, A. Hiller, M. Diekers, K. Strecker, K. Wohlfarth, C. Allgaier, J. Steinbach, and A. Hoepping, GABA A receptor pharmacology of fluorinated derivatives of the novel sedative-hypnotic pyrazolopyrimidine indiplon, Eur. J. Pharmacol., vol. 580, p.1–11, (2008).

[24] A. Hoepping, M. Diekers, W. Deuther-conrad, M. Scheunemann, S. Fischer, A. Hiller, F. Wegner, J. Steinbach, and P. Brust, Synthesis of fluorine substituted pyrazolopyrimidines as potential leads for the development of PET-imaging agents for the GABA A receptors, Bioorg. Med. Chem., vol. 16, p.1184–1194, (2008).

[25] A. Lippa, P. Czobor, J. Stark, B. Beer, E. Kostakis, M. Gravielle, S. Bandyopadhyay, S. J. Russek, T. T. Gibbs, D. H. Farb, and P. Skolnick, Selective anxiolysis produced by ocinaplon , a GABA A receptor modulator, PNAS, vol. 102, no. 20, p.7380–7385, (2005).

[26] N. R. Mirza, R. J. Rodgers, and L. S. Mathiasen, Comparative Cue Generalization Profiles of L-838 , 417 , Zopiclone , and Various Benzodiazepines in Chlordiazepoxide and Zolpidem Drug Discrimination, J. Pharmacol. Exp. Ther., vol. 316, no. 3, p.1291–1299, (2006).

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