[CH3:1][N:2]1[C:10]2[CH2:9][CH2:8][CH2:7][CH:6]([C:11]([O-:13])=[O:12])[C:5]=2[CH:4]=[N:3]1.[Li+].[OH-].Cl>CO.C1COCC1.O>[CH3:1][N:2]1[C:10]2[CH2:9][CH2:8][CH2:7][CH:6]([C:11]([OH:13])=[O:12])[C:5]=2[CH:4]=[N:3]1To a solution of 1-methyl-4,5,6,7-tetrahydro-1H-indazole-4-carboxylate (7 g, 36 mmol) in methanol (100 mL), THF (50 mL) and H2O (50 mL) was added LiOH (2.5 g, 108 mmol). The resulting mixture was stirred at room temperature for 2 hours. The reaction mixture was acidified with 1N HCl solution to pH=5-6, and extracted with EA three times. The combined organic layers were washed with brine, dried over Na2SO4. The solvent was concentrated to give 1-methyl-4,5,6,7-tetrahydro-1H-indazole-4-carboxylic acid (6 g, 94%), which was used in the next step directly.
Loading…