Diisobutylaluminumhydride → (3-bromo-1-cyclobutyl-1H-pyrazol-4-yl)methanol

Temperature

-78 °C

A solution of ethyl 3-bromo-1-cyclobutyl-1H-pyrazole-4-carboxylate (565 mg, 2.07 mmol) in tetrahydrofuran (10 mL) was cooled to −78° C. Diisobutylaluminum hydride (4.13 mL, 6.02 mmol, 1.5 M in toluene) was added slowly and the reaction was stirred at −78° C. for 1 hour. The reaction was then allowed to warm to room temperature and stir for an additional 2 hours. The reaction was diluted with ethyl acetate (20 mL) and saturated aqueous Rochelle's salt (20 mL). The mixture was stirred at room temperature overnight. The mixture was further diluted with ethyl acetate and was washed with water. The aqueous layer was extracted with ethyl acetate and the combined organics were dried over sodium sulfate, filtered, and concentrated to yield the title compound (478 mg, 100%) as a colorless oil. +APCI (M+H+1) 233.1; 1H NMR (400 MHz, CDCl3, δ): 7.40 (s, 1H), 4.62-4.71 (m, 1H), 4.51 (s, 2H), 2.39-2.59 (m, 4H), 1.74-1.92 (m, 3H).

1. temperatureto warm to room temperature
2. stirringstir for an additional 2 hours
3. stirringThe mixture was stirred at room temperature overnight
4. washwas washed with water
5. extractionThe aqueous layer was extracted with ethyl acetate
6. dry with materialthe combined organics were dried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated

ORD record

ord-14fc16fca6b746f3bff4edf8929feae3

Source dataset

uspto-grants-2015_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09181252B2