反应详情

温度

10 °C

A mixture of 5-amino-3-t-butyl-1-p-tolylpyrazole hydrochloride (300 g, 1.13 mol), water (0.9 L), EtOAc (2.1 L) and NaOH (117 g, 2.84 mol) was stirred between 5-15° C. for 30 min. To this mixture, 2,2,2-trichloroethyl chloroformate (342 g, 1.58 mol) was added over 1 h between 5-15° C. The mixture was stirred at room temperature for 2 h, and then the aqueous layer was separated from the EtOAc layer. The EtOAc layer was washed with brine (2×0.9 L) and dried over MgSO4 (60 g). The EtOAc layer was collected by filtration. To this solution, heptane was added. A part of the solution was removed by distillation. The product was crystallized from the solution, collected by filtration and dried in vacuum oven to constant weight. Yield: 409 g, 90%. 1H NMR (CDCl3) δ 7.40 (d, 2H), 7.30 (d, 2H), 6.40 (s, 1H), 4.80 (s, 2H), 2.40 (s, 3H), 1.40 (s, 9H). MS (EI) m/z 404 (M+).

1. stirringThe mixture was stirred at room temperature for 2 h
2. customthe aqueous layer was separated from the EtOAc layer
3. washThe EtOAc layer was washed with brine (2×0.9 L)
4. dry with materialdried over MgSO4 (60 g)
5. filtrationThe EtOAc layer was collected by filtration
6. additionTo this solution, heptane was added
7. customA part of the solution was removed by distillation
8. customThe product was crystallized from the solution
9. filtrationcollected by filtration
10. customdried in vacuum oven to constant weight