反应详情

温度

25 °C

To a stirring suspension of benzyl 5-hydroxy-3-methyl-1-phenyl-1H-pyrazole-4-carboxylate (3380 mg, 1 mmol) in chlorobenzene (30 mL) at 10° C. under nitrogen was added trimethylaluminum (16 mL, 33 mmol, 2M in toluene). Internal temperature reached 27° C. At 25° C., 1,2-epoxy-2-methylpropane (1000 mg, 16 mmol) was added. The reaction mixture was stirred for 3 h at 25° C., and then diluted with THF (500mL). The resultant was chilled to 10° C., and sodium sulfate decahydrate (2g) was added. After 1hr, another 2 g of sodium sulfate decahydrate added. After 2 h, the gel was filtered through a bed of celite and washed with EtOAc (3×100mL). The filterate was then washed with aq. 1M HCl (50mL) and brine. The organic layer was dried over MgSO4. and concentrated. The residue was purified on 120 g silica chromatography (30>90% EtOAc/hex). To give the title compound (1.11 g, 27% yield) as an amorphous solid. MS (ESI pos. ion) m/z: 381 (MH+). Calc'd exact mass for C22H24N2O4 380.

1. customreached 27° C
2. temperatureThe resultant was chilled to 10° C.
3. waitAfter 1hr
4. waitAfter 2 h
5. filtrationthe gel was filtered through a bed of celite
6. washwashed with EtOAc (3×100mL)
7. washThe filterate was then washed with aq. 1M HCl (50mL) and brine
8. dry with materialThe organic layer was dried over MgSO4
9. concentrationand concentrated
10. customThe residue was purified on 120 g silica chromatography (30>90% EtOAc/hex)