Title:Antitubercular and Antimicrobial Activity of NH4VO3 Promoted 1,4- Dihydropyridine Incorporated 1,3,4-trisubstituted Pyrazole
Volume: 14
Issue: 6
Author(s): Nandam Harikrishna, Arun M. Isloor*, K. Ananda, Tanya Parish, Joazaizulfazli Jamalis, Hazem A. Ghabbour and Hoong-Kun Fun
Affiliation:
- Department of Chemistry, Medicinal Chemistry Laboratory, National Institute of Technology Karnataka, Surathkal, Mangalore 575025,India
Keywords:
1, 3, 4-Trisubstituted pyrazole, 1, 4-dihydropyridine, multistep reaction, ammonium metavanadate, antitubercular
study, antimicrobial studies.
Abstract: Background: A new series of pyrazole containing 1,4-dihydropyridine derivatives 5a-i and
6a-i were synthesized from substituted acetylated aryls and substituted phenylhydrazine by the multistep
reaction.
Method: The target compounds 1,4-dihydropyridine derivatives were obtained from green synthesis
of 1,3-disubstituted phenyl-1H-pyrazole-4-carbaldehydes 4a-i with ethyl acetoacetate and methyl
acetoacetate at higher temperatures in the presence of ammonium acetate and the catalytic amount of
ammonium metavanadate (NH4VO3). The role of ammonium metavanadate was increases rate of the
reaction and obtained high yields.
Result: Structures of newly synthesized 1,4-dihydropyridine moiety containing pyrazole derivatives
were confirmed by FT-IR, NMR and Mass spectral studies. The structure of compound 5b was
confirmed by S-XRD study. Further, these compounds were tested for in-vitro antitubercular and
antimicrobial studies. Compounds 5a, 5b, 5i, 6a, 6b, 6g, 6h, and 6i were found to be active against all
the bacterial microorganisms.
Conclusion: The above mentioned compounds have shown lowest MIC ranging between 3.12-12.5
μg/ml against Mycobacterium tuberculosis and MIC values ranging between 7.8- 15.6 μg/ml for
Mycobacterium smegmatis, Staphylococcus aureus and Pseudomonas aeruginosa. For the control of
life threatening diseases such as tuberculosis, these eight compounds may be strongly promising
synthetic compounds.