Potassium Hydroxide → 7-(2-Chloro-4-methoxyphenyl)-2,6-dimethylpyrazolo[1,5-a]pyridine-3-carboxylic acid

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Reaction Steps

A solution of ethyl 7-(2-chloro-4-methoxyphenyl)-2,6-dimethylpyrazolo[1,5-a]pyridine-3-carboxylate (0.82 g, 2.3 mmol) in ethanol (14 mL), THF (8 mL) and H2O (8 mL) was treated with KOH (3.12 g, 55.6 mmol) and stirred at room temperature for 8 days adding more KOH periodically. The reaction was concentrated in vacuo and the residue partitioned between Et2O and H2O. The aqueous layer was acidified with concentrated HCl, extracted with ethyl aceatate, washed with brine, dried over MgSO4 and filtered. The filtrate was concentrated in vacuo to give a brown solid (0.60 g, 79%) as the title compound: 1H NMR (400 MHz, CDCl3) δ 8.18 (d, J=9.0 Hz, 1H), 7.43 (d, J=9.0 Hz, 1H), 7.30 (d, J=8.5 Hz, 1H), 7.16 (d, J=2.5 Hz, 1H), 7.04 (dd, J=8.5, 2.5 Hz, 1H), 3.93 (s, 3H), 2.67 (s, 3H), 2.19 (s, 3H); HRMS (FAB) calcd for C17H15N2O3Cl+H 331.0849. found 331.0853.

Provenance & Evidence