反应详情

1-(2-Hydroxyethyl)-5-aminopyrazole (5 g) was added to acetic anhydride (14.7 ml) under stirring and ice-cooling, and pyridine (6.3 ml) was added thereto. The mixture was stirred for 2 hours at 25° C. The reaction mixture was added to a mixture of ethyl acetate (50 ml) and brine (50 ml). Then, the mixture was adjusted to pH 7.0 with an aqueous solution of sodium bicarbonate. The aqueous layer was extracted with a mixture of ethyl acetate and tetrahydrofuran. The extract was dried over magnesium sulfate. The magnesium sulfate was filtered off, and the filtrate was evaporated under reduced pressure to give 1-(2-acetoxyethyl)-5-acetylaminopyrazole (5.98 g).

1. temperatureice-cooling
2. stirringThe mixture was stirred for 2 hours at 25° C
3. extractionThe aqueous layer was extracted with a mixture of ethyl acetate and tetrahydrofuran
4. dry with materialThe extract was dried over magnesium sulfate
5. filtrationThe magnesium sulfate was filtered off
6. customthe filtrate was evaporated under reduced pressure