Background: Nitrogen-containing heterocyclics are abundant in natural products and
also in synthetic drug molecules because of a variety of applications and superior pharmacological
profile action. Pyrazoles are the integral architects of many of the heterocyclic compounds with superior
Methods: Two series of the pyrazole conjugated Benzothiazole derivatives were synthesized. The
pyrazoles were synthesized by the Vilsmeier-Haack reaction and then conjugated with benzothiazole
hydrazine and hydrazide by imine bond formation. The synthesized compounds were screened
for anti-mitotic activity using Allium assay.
Results: Here, the anti-mitotic activity, the percentage of cell division and the percentage of inhibition
compared to the control were calculated. Compound 4b (-OMe), 4c (-OH), 5b (-OMe), 5c (-
OH) and 5d (-CH3) had electron donating groups which showed excellent activity, was followed by
4f and 5f where they contain p-Bromo substitution, showing moderate activity.
Conclusion: In the two series, benzothiazole linked to pyrazole through the hydrazide bridging
(5a-5i) had superior to hydrazine bridging (4a-4i). The observed chromosomal aberrations are because
of the structural morphology and binding sites of the molecule with the chromosome.