Diisobutylaluminumhydride → HCID 67491360, compound

Temperature

-78 °C

A solution of ethyl 5-bromo-1-tert-butyl-1H-pyrazole-4-carboxylate (685 mg, 2.49 mmol) in THF (20 mL) was cooled to −78° C. and treated with diisobutylaluminum hydride (7.47 mL, 7.47 mmol, 1 M THF), dropwise. The mixture was stirred at −78° C. for 30 minutes and then warmed to room temperature for 18 hours. The mixture was quenched with ethyl acetate 10 mL) and stirred 15 minutes. The mixture was then treated with saturated aqueous Rochelle's salt (25 mL) and stirred 1 hour at room temperature. The mixture was diluted with ethyl acetate (100 mL) and washed with water (100 mL). The organic layer was dried over sodium sulfate, filtered and concentrated. The residue was purified by flash chromatography (10-80% ethyl acetate/heptane gradient, 25 g silica gel) to yield 460 mg of (5-bromo-1-tert-butyl-1H-pyrazol-4-yl)methanol as a clear oil. +APCI (M+H) 233.1, (M+2+H) 235.1; 1H NMR (400 MHz, CDCl3, δ): 7.51 (s, 1H), 4.53 (d, 2H), 1.74 (s, 9H), 1.55 (t, J=5.8 Hz, 1H).

1. temperaturewarmed to room temperature for 18 hours
2. customThe mixture was quenched with ethyl acetate 10 mL) and
3. stirringstirred 15 minutes
4. additionThe mixture was then treated with saturated aqueous Rochelle's salt (25 mL)
5. stirringstirred 1 hour at room temperature
6. additionThe mixture was diluted with ethyl acetate (100 mL)
7. washwashed with water (100 mL)
8. dry with materialThe organic layer was dried over sodium sulfate
9. filtrationfiltered
10. concentrationconcentrated
11. customThe residue was purified by flash chromatography (10-80% ethyl acetate/heptane gradient, 25 g silica gel)

ORD record

ord-9933a713fb5040799e5188ea3ca54d31

Source dataset

uspto-grants-2015_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09181252B2