1-[7-Chloro-2-(3-methylphenyl)pyrazolo[1,5-a]pyridin-3-yl]-2-propyn-1-ol → 1-[7-Chloro-2-(3-methylphenyl)pyrazolo[1,5-a]pyridin-3-yl]-2-propyn-1-one

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Reaction Steps

To a solution of 1-[7-chloro-2-(3-methylphenyl)pyrazolo[1,5-a]pyridin-3-yl]-2-propyn-1-ol (11.3 g, 36.2 mmol) in chloroform (300 mL) was added manganese dioxide (78.9 g, 905 mmol). The reaction mixture was stirred at room temperature for 18 hours. The suspension was filtered through a pad of Celite and the filtrate was concentrated and purified by flash chromatography (7:3 hexanes:ethyl acetate). 1-[7-chloro-2-(3-methylphenyl)pyrazolo[1,5-a]pyridin-3-yl]-2-propyn-1-one (4.57 g, 41%) was obtained as a pale yellow crystalline. 1H NMR (CDCl3) δ 8.48 (d, 1H), 7.51 (m, 3H), 7.33 (t, 1H), 7.29 (d, 1H), 8.21 (dd, 1H), 2.89 (s, 1H), 2.42 (s, 3H); MS m/z 295 (M+1).

Provenance & Evidence