反应详情

A 2N-aqueous sodium hydroxide solution (0.63 ml, 1.3 mmol) was added to a solution of methyl 1-acetyl-6-methyl-1H-indazole-5-carboxylate (0.0731 g, 0.315 mmol) in tetrahydrofuran (1 ml), and the resulting mixture was stirred for 3 hours with heating under reflux. Then, a 2N-aqueous lithium hydroxide solution (0.63 ml, 1.3 mmol) was added thereto and stirred for another 3 hours. The resulting solution was diluted with water and washed with diethyl ether, and the aqueous layer was adjusted to pH 1 to 2 with 1N-hydrochloric acid to precipitate a solid. The solid precipitated was collected by filtration and the precipitate on a filter was washed with water and dried under reduced pressure to obtain 6-methyl-1H-indazole-5-carboxylic acid (0.0514 g, 93%).

1. temperaturewith heating
2. temperatureunder reflux
3. stirringstirred for another 3 hours
4. washwashed with diethyl ether
5. customto precipitate a solid
6. customThe solid precipitated
7. filtrationwas collected by filtration
8. washthe precipitate on a filter was washed with water
9. customdried under reduced pressure