反应详情

温度

50 °C

A 250-mL, 3-neck round bottom flask was charged with N-(3-chloro-1H-pyrazol-4-yl)acetamide (4.75 g, 29.8 mmol) and tetrahydrofuran (50 mL). Borontrifluoride etherate (7.8 mL, 74.4 mmol) was added and the mixture was stirred for 15 minutes. Sodium borohydride (3.38 g, 89 mmol) was added (off-gassing) and the reaction was heated at 50° C. for 4 hours, at which point thin layer chromatography analysis [Eluent: ethyl acetate, sample was prepared by treatment of reaction mixture with hydrochloric acid, followed by sodium bicarbonate basification and ethyl acetate extraction] indicated that the reaction was complete. Water (40 mL) was added (off-gassing), followed by concentrated hydrochloric acid (6 mL, off-gassing). The mixture was heated at 50° C. for 5 hours and allowed to cool to 20° C. and stirred for 16 hours. The mixture was concentrated under reduced pressure to remove tetrahydrofuran and basified with sodium bicarbonate. Ethyl acetate (50 mL) was added and the layers were separated. The aqueous layer was extracted with ethyl acetate (25 mL) and the combined organic layers were concentrated to dryness to afford a colorless oil (2.80 g, 65%): 1H NMR (400 MHz, DMSO-d6) δ 12.30 (s, 1H), 7.20 (d, T=1.6 Hz, 1H), 3.94 (s, 1H), 2.87 (q, J=7.1 Hz, 2H), 1.11 (t, J=7.1 Hz, 3H); 13C NMR (101 MHz, DMSO) δ 129.18, 127.11, 115.03, 41.06, 14.56; EIMS m/z 145 ([M]+).

1. temperatureto cool to 20° C.
2. stirringstirred for 16 hours
3. concentrationThe mixture was concentrated under reduced pressure
4. customto remove tetrahydrofuran
5. additionEthyl acetate (50 mL) was added
6. customthe layers were separated
7. extractionThe aqueous layer was extracted with ethyl acetate (25 mL)
8. concentrationthe combined organic layers were concentrated to dryness