Hydrogen Bromide → (2R)-2-bromo-4-methylpentanoic acid

Temperature

0 °C

D-Leucine (8.2 g, 62.7 mmol) was dissolved in 3.0M HBr in water (99 mL, 0.3 mol) and cooled to 0° C. A solution of NaNO2 (6.9 g, 100 mmol) in water (11.3 mL, 627 mmol) was slowly added over 20 minutes. The mixture was stirred at 0° C. for 3 hours and then extracted twice with ethyl ether, washed with water then saturated aqueous NaCl, dried over MgSO4, filtered, and concentrated to afford (R)-2-bromo-4-methylpentanoic acid (11.5 g) as an off-yellow oil. This was taken on to the next step without further purification.

1. extractionextracted twice with ethyl ether
2. washwashed with water
3. dry with materialsaturated aqueous NaCl, dried over MgSO4
4. filtrationfiltered
5. concentrationconcentrated

ORD record

ord-8db002f27d1846ca92169435aea24cac

Source dataset

uspto-grants-2015_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09221763B2