Title:Synthesis of Nitrogen and Oxygen based Pyrazole Derivatives and Its Antitubercular and Antimicrobial Activity
VOLUME: 13 ISSUE: 2
Author(s):Khushal M. Kapadiya, Kishor M. Kavadia, Parth A. Manvar and Ranjan C. Khunt
Affiliation:Chemical Research Laboratory, Department of chemistry, Saurashtra University, Rajkot-360005 (Gujarat) India.
Keywords:Antitubercular screening, Antimicrobial screening, Aminopyrimidines, Isoxazoles, Chalcones.
Abstract:Background: Pyrazole, oxazole and pyrimidine are nitrogen containing heterocycles which
possess very good binding efficiency with receptor or proteins. Due to this effect it can be work as antitubercular
agents with active substituents. The objective of this paper is clubbed the heterocycles to
enhance their antitubercular potency. Methods: The active substituted pyrazole aldehydes were synthesized
by reaction of phenyl hydrazine with different acetophenone followed by Vilsmeier-Haack
formylation reaction. The isoxazole and aminopyrimidines were prepared by condensation of various chalcones with hydroxyl
amine hydrochloride and guanidine hydrochloride respectively. The structures of the newly synthesized compounds
were characterized by 1H-NMR, Mass, IR and elemental analysis data. All the newly synthesized compounds were
screened for their antibacterial activity against Gram-positive S.pyogenus and Gram negative E.coli, Paeruginosa,
S.aureus and antitubercular activity against mycobacterium tuberculosis H37Rv. Results: Oxygen containing substituent
in aromatic ring or heterocycles as a substituent were enhancing the antitubercular activity as compared to the other substituents.
Ethoxy group present as a substituent in aromatic ring shows minimum inhibition concentration as compared to
others. Conclusion: X-ray crystallographic study enhances that E-isomer formed in case of chalcones. The electron withdrawing
group such as fluorine and chlorine enhancing the activity of Isoxazole and Pyridine as compare to the chalcones.
Electron donating group such as ethoxy is increase the potency of the compounds at para position.
