Sodium Hydroxide → 2-(6-Methyl-pyridin-2-yl)-pyrazolo[1,5-a]pyridine-3-carboxylic acid
Reaktionsgleichung
C([O:3][C:4]([C:6]1[C:7]([C:15]2[CH:20]=[CH:19][CH:18]=[C:17]([CH3:21])[N:16]=2)=[N:8][N:9]2[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=12)=[O:5])C.[OH-].[Na+]>CCO>[CH3:21][C:17]1[N:16]=[C:15]([C:7]2[C:6]([C:4]([OH:5])=[O:3])=[C:10]3[CH:11]=[CH:12][CH:13]=[CH:14][N:9]3[N:8]=2)[CH:20]=[CH:19][CH:18]=1Komponenten
4
Versuchsvorschrift
A solution of 2-(6-methyl-pyridin-2-yl)-pyrazolo[1,5-a]pyridine-3-carboxylic acid ethyl ester (0.18 g, 0.6 mmol) in EtOH (10 mL) is treated with a 2N NaOH solution (3 mL) and refluxed for 3 hours. The reaction is concentrated to a yellow solid and diluted with 1N HCl (30 mL). The aqueous is extracted with CH2Cl2 (3×10 mL) and the organic solution dried over Na2SO4. The solution is filtered and the solvent removed in vacuo to afford 0.152 g (94%) of desired product as a white solid. MS ES+ m/e 254.1 (M+1). UV (95% EtOH) λmax 284 nm (ε 23625), 244 nm (ε 24036). TOF MS ES+ exact mass calculated for C14H11N3O2 (p+1): m/z=254.0930. Found: 254.0919. Anal. Calcd for C14H11N3O2: C, 66.40; H, 4.38; N, 16.59. Found: C, 66.22; H, 4.42; N, 16.25.