[CH2:1]([N:3]1[C:7]2=[N:8][C:9]([CH2:24][CH3:25])=[C:10]([C:19]([O:21]CC)=[O:20])[C:11]([NH:12][CH:13]3[CH2:18][CH2:17][O:16][CH2:15][CH2:14]3)=[C:6]2[CH:5]=[N:4]1)[CH3:2].[Li+].[OH-].CO.Cl>O.[Cl-].[Na+].O>[CH2:1]([N:3]1[C:7]2=[N:8][C:9]([CH2:24][CH3:25])=[C:10]([C:19]([OH:21])=[O:20])[C:11]([NH:12][CH:13]3[CH2:18][CH2:17][O:16][CH2:15][CH2:14]3)=[C:6]2[CH:5]=[N:4]1)[CH3:2]A mixture of ethyl 1,6-diethyl-4-(tetrahydro-2H-pyran-4-ylamino)-1H-pyrazolo[3,4-b]pyridine-5-carboxylate (2 g, 4.30 mmol), LiOH (901 mg, 21.48 mmol), water (4 mL) and methanol (8 mL) was heated at microwave for 20 min at 80° C. The reaction mixture was diluted with water and then washed with ethyl acetate to get rid of starting material. The aqueous layer was then acidified with 2N HCl, saturated with brine and then extracted with a mixture of DCM and IPA (3:1 ratio) twice. The combined organic layers were dried under vacuum to give a crude product. It was triturated with ether to give pure product 1,6-diethyl-4-(tetrahydro-2H-pyran-4-ylamino)-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid as a yellow solid (2.78 g, 95%). LC-MS m/z 319 (M+H)+.
Loading…