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-6325552a65ea474897b31ac4ccefe38c

Source dataset

uspto-grants-2014_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08889882B2