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
Reaction equation
[Cl:1][C:2]1[N:7]2[N:8]=[C:9]([C:15]3[CH:20]=[CH:19][CH:18]=[C:17]([CH3:21])[CH:16]=3)[C:10]([CH:11]([OH:14])[C:12]#[CH:13])=[C:6]2[CH:5]=[CH:4][CH:3]=1>C(Cl)(Cl)Cl.[O-2].[O-2].[Mn+4]>[Cl:1][C:2]1[N:7]2[N:8]=[C:9]([C:15]3[CH:20]=[CH:19][CH:18]=[C:17]([CH3:21])[CH:16]=3)[C:10]([C:11](=[O:14])[C:12]#[CH:13])=[C:6]2[CH:5]=[CH:4][CH:3]=1Participants
4
Reactant 1
Product 1
Reagents, catalysts & solvents 2
Procedure
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).