反应详情

To a solution methyl 3-cyclopropyl-4,5,6,7-tetrahydro-1H-indazole-5-carboxylate (35.0 g) in MeOH (300 mL) was added a solution of LiOH.H2O (10.8 g, 0.26 mol) in H2O (200 mL) at 0° C. After stirring 18 h at rt the solvent was removed in vacuum. To the residue water (200 mL) was added and aqueous solution was acidified to pH=4-5 with 10% HCl. The precipitate was collected by filtration to give 3-cyclopropyl-4,5,6,7-tetrahydro-1H-indazole-5-carboxylic acid (25.0 g, 80% yield for 2 steps).

1. customwas removed in vacuum
2. additionTo the residue water (200 mL) was added
3. filtrationThe precipitate was collected by filtration