Background: In the past few decades, design, synthesis, and characterization of novel
heterocyclic compounds with auspicious biological profile received the considerable attention of
the scientific community. Among them, the small and simple organic molecular backbone like triazole
moiety have a broad spectrum of applications in the medicinal as well as diagnostic areas.
Objective: The objective of present study was synthesis, characterization, and exploration of biological
profile of 4-(2-fluorophenyl)-3-(3-methoxybenzyl)-1H-1,2,4-triazole-5(4H)-one (5). The
tautomeric interconversion of the molecule was observed by the single crystal XRD and DFT
Methods: N-(2-fluorophenyl)-2-[2-(3-methoxyphenyl)acetyl]hydrazine carboxamide (4) was synthesized
by the condensation of 2-(3-methoxyphenyl)acetohydrazide (3) with 1-fluoro-2-
isocyanatobenzene. The dehydrocyclization of compound (4) yielded target compound (5) by refluxing
in 2 N aqueous sodium hydroxide solutions. The target molecule was characterized by FTIR,
1H NMR, 13C NMR, single crystal X-ray diffraction analysis and DFT calculation. The enzymatic
assay measurements were carried out by using a microplate reader (OPTI Max, Tunable Microplate
Reader; Wavelength range: 340-850 nm; for 96-well plates) while DFT calculation was
performed by Gaussian 09 package.
Results: The XRD result and DFT calculations showed that molecule 5 predominantly exists in
thione conformation and crystallized in the triclinic system of P-1 space group. Furthermore, for
the practical applicability of synthesized compound 5, the in vitro acetylcholinesterase as well as
α-glucosidase inhibition activities were performed and found moderate enzyme inhibition potential
comparable with that of reference inhibitors.
Conclusion: This study might be helpful for future design and development of potent enzyme inhibitor
to control Alzheimer's as well as diabetic disease. The DFT and single crystal XRD analysis
data might be helpful for understanding the mechanism of drug binding and its mode of action.