Abstract

A NOVEL PYRAZOLO[1,5-A]PYRIDINE DERIVATIVES WITH ARYL UREA, THIOUREA AND SULFONAMIDE MOIETIES: SYNTHESIS AND CYTOTOXICITY EVALUATIONS AGAINST MCF-7 CELL LINES

Shivaji S. Pandit*

ABSTRACT

A series of pyrazolo[1,5-a]pyridine derivatives bearing aryl urea, thiourea and sulfonamide moieties of biological interest were synthesized. The core pyrazolo[1,5-a]pyridin-2-amine was assembled by cyclization of 2-(pyridin-2-yl)acetonitrile by reaction with O-(mesitylsulfonyl)hydroxylamine in the presence of triethylamine. The pyrazolo[1,5-a]pyridin-2-amine was converted to designed analogues by reaction with suitable isocyanate or thioisocyanate or sulfonyl chloride. All synthesized compounds evaluated for cytotoxicity against the breast cancer cell in term of the growth inhibition (GI50) in micro molar to sub milimolar range. Further evaluation of SAR showed that the thiourea derivatives of the pyrazolo[1,5-a]pyridine showed the activity rather the urea derivatives and sulfonamide derivatives. Inhibitor 19 and 22 showed the highest cytotoxicity among the synthesized compound with GI50 of 3.15 μM and 3.2 μM.

Keywords: Pyrazolo[1,5-a]pyridine, Urea, Thiourea, Sulfonamide, MCF-7.