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

Temperature

0 °C

The (R)-2-amino-4-methylpentanoic acid (H-D-Leu-OH, 4 g, 30.5 mmol) was dissolved in a mixture of HBr 48% (9.6 mL, 84 mmol) and H2O (30 mL). At 0° C., a solution of NaNO2 (2.62 g, 38 mmol) in H2O (15 mL) was added over a period of 60 min. The reaction was stirred for 1.5 hours at 0° C. and 1.5 hours at room temperature. The reaction mixture was degassed in vacuo and extracted with ethyl acetate (EtOAc) (3×50 mL). The extract was washed with water (50 mL), dried (Na2SO4), filtered and evaporated to give 4.52 g crude as oil. The oil was distillated at high vacuum to obtain 3.56 g of (R)-2-bromo-4-methylpentanoic acid as oil.

1. customThe reaction mixture was degassed in vacuo
2. extractionextracted with ethyl acetate (EtOAc) (3×50 mL)
3. washThe extract was washed with water (50 mL)
4. dry with materialdried (Na2SO4)
5. filtrationfiltered
6. customevaporated
7. customto give 4.52 g crude as oil

ORD record

ord-8c8edd4bb96d421ea75e17ed70d0c082

Source dataset

uspto-grants-2015_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09212206B1