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-bac6cd0a8b074c5cbfc29cc466c78f66

Source dataset

uspto-grants-2013_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08399501B2