反应详情

Methyl 3-cyano-1H-indazole-5-carboxylate (500 mg, 2.5 mmol) was dissolved in methanol (12 mL) and 2 N aqueous lithium hydroxide (3.7 mL, 7 mmol) was added. The reaction was stirred at room temperature overnight. The reaction mixture was concentrated to remove the methanol and the residue was acidified to pH=4 with 1 N aqueous hydrochloric acid. The resulting yellow precipitate was collected by filtration, washed with water, and dried in a vacuum oven to provide the title compound (445 mg, 96%). −ESI (M−H) 186.4; 1H NMR (400 MHz, DMSO-d6, δ): 13.17 (br. s., 1H), 8.42 (s, 1H), 8.05 (dd, J=8.8, 1.6 Hz, 1H), 7.83 (d, 1H).

1. concentrationThe reaction mixture was concentrated
2. customto remove the methanol
3. filtrationThe resulting yellow precipitate was collected by filtration
4. washwashed with water
5. customdried in a vacuum oven