反应详情

To a solution of methyl 3-cyano-1H-indazole-5-carboxylate (2.5 g, 12 mmol) in ethanol (40 mL), a solution of lithium hydroxide (1.04 g, 24.9 mmol) in water (15 mL) was added and stirred at ambient temperature for 16 h. The mixture was concentrated and the obtained residue was dissolved in water (25 mL) and washed with ethyl acetate (20 mL). The aqueous layer was acidified with 10% citric acid solution, the obtained precipitate was filtered, washed with 50% ethyl acetate in petroleum ether (2×10 mL) and dried to afford the title compound (1.9 g, 82%) as a brown solid. 1HNMR (DMSO-d6) δ ppm 13.8-12.4 (br, 2H), 8.44 (s, 1H), 8.1 (d, 1H), 7.82 (d, 1H).

1. concentrationThe mixture was concentrated
2. dissolutionthe obtained residue was dissolved in water (25 mL)
3. washwashed with ethyl acetate (20 mL)
4. filtrationthe obtained precipitate was filtered
5. washwashed with 50% ethyl acetate in petroleum ether (2×10 mL)
6. customdried