Diisobutylaluminumhydride → 3-(4-Bromo-pyrazol-1-yl)-3-methyl-butan-1-ol

Temperature

-10 °C

Diisobutylaluminium hydride (1 M in toluene, 10.43 mL) was added dropwise to a solution of ethyl 3-(4-bromo-1H-pyrazol-1-yl)-3-methylbutanoate (Compound 50E, 1.3 g, 4.74 mmol), in THF (30 mL) at −78° C. and allowed to stir for 3 hours eventually warming to −10° C. The reaction mixture was quenched with an aqueous solution of K/Na tartrate tetrahydrate (10 mL) and allowed to stir for 2 hours. The mixture was extracted with ethyl acetate (3×15 mL) and the combined organic extracts were washed with water, followed by brine, dried over sodium sulfate, filtered and concentrated to afford 1.0 g of the desired product (91%). 1H NMR (300 MHz, CDCl3) δ 7.51 (s, 1H), 7.46 (s, 1H), 3.54-3.58 (q, J=4.5 Hz, 2H), 2.28 (t, J=4.2 Hz, 1H), 2.09 (t, J=4.5 Hz, 2H), 1.58 (s, 6H).

1. customThe reaction mixture was quenched with an aqueous solution of K/Na tartrate tetrahydrate (10 mL)
2. stirringto stir for 2 hours
3. extractionThe mixture was extracted with ethyl acetate (3×15 mL)
4. washthe combined organic extracts were washed with water
5. dry with materialdried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated

ORD record

ord-e2874c8a413e460080d9b666ea32d0fb

Source dataset

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09133224B2