反应详情

温度

50 °C

A suspension of 3-methyl-1-phenyl-1H-pyrazol-5-ol (10.0 g, 57 mmol) and calcium hydroxide (8.5 g, 115 mmol) in dry 1,4-dioxane (100 mL) was heated to 50° C. for 20 min. The suspension was chilled to 10° C. and benzyl chloroformate (8.2 ml, 57 mmol) was in dioxane (10 mL) added. The resultant was heated to 90° C. for 3 h, cooled to 25° C. and then, chilled (0° C.) 1 M HCl (200 mL) was added. The mixture was stirred at 25° C. overnight. A solid collected by filtration was washed with cold EtOH (2×25 mL) and ether (50 mL), dried at 80° C. (sand bath) exposed to air for 4 h to give the title compound (14.0 g, 79% yield) as an off-white solid. MS (ESI pos. ion) m/z: 309 (MH+). Calc'd exact mass for C18H16N2O3 308.

1. temperatureThe suspension was chilled to 10° C.
2. additionadded
3. temperatureThe resultant was heated to 90° C. for 3 h
4. temperaturecooled to 25° C.
5. additionwas added
6. filtrationA solid collected by filtration
7. washwas washed with cold EtOH (2×25 mL) and ether (50 mL)
8. customdried at 80° C. (sand bath)
9. waitexposed to air for 4 h