反应详情

To 1-ethyl-1H-pyrazole-3-carboxylic acid (5.01 g, 35.7 mmol) in benzene/MeOH (45 mL/10 mL) at 0° C. was added dropwise (diazomethyl)trimethylsilane (19.7 mL, 39.3 mmol) in hexanes (2M). The cold bath was removed and the reaction mixture was stirred at ambient temperature for one hour. The reaction was quenched with the addition of acetic acid (0.25 mL). The mixture was concentrated under reduced pressure to give crude product, to which was added THF (50 mL) and the solution was cooled to 0° C. Lithium aluminum hydride (1.36 g, 35.7 mmol) was added cautiously to the solution. The cold bath was removed once the addition was complete. The mixture was stirred at ambient temperature for 2 hours and the reaction was quenched by careful addition of sodium sulfate decahydrate. The mixture was filtered through Celite, and the filter pad was washed with EtOAc (200 mL). The filtrate was concentrated under reduced pressure to give the product (4.41 g).

1. customThe cold bath was removed
2. customThe reaction was quenched with the addition of acetic acid (0.25 mL)
3. concentrationThe mixture was concentrated under reduced pressure
4. customto give crude product
5. temperaturethe solution was cooled to 0° C
6. customThe cold bath was removed once the addition
7. stirringThe mixture was stirred at ambient temperature for 2 hours
8. customthe reaction was quenched by careful addition of sodium sulfate decahydrate
9. filtrationThe mixture was filtered through Celite
10. washthe filter pad was washed with EtOAc (200 mL)
11. concentrationThe filtrate was concentrated under reduced pressure