DL-leucine → Methyl DL-leucinate hydrochloride

2-Amino-4-methylpentanoic acid (5.0 g 38.2 mmol) was slowly added to sat. HCl/MeOH (50 mL). The mixture was stirred (RT, 5 h) then heated to reflux (16 h). After the reaction, the solvent was removed under reduced pressure. The residue was diluted with water (50 mL), then NaHCO3 was added to adjust pH=7. The mixture was then extracted with DCM (3×50 mL), the combined organic layers were dried over MgSO4, concentrated under reduced pressure to afford methyl 2-amino-4-methylpentanoate as a colorless liquid (5.3 g, 96%). Mass calculated for C7H15NO2=145.20; found: [M+H]+=145.9. The product was used in next step without further purification.

1. temperaturethen heated
2. temperatureto reflux (16 h)
3. customAfter the reaction
4. customthe solvent was removed under reduced pressure
5. additionThe residue was diluted with water (50 mL)
6. additionNaHCO3 was added
7. extractionThe mixture was then extracted with DCM (3×50 mL)
8. dry with materialthe combined organic layers were dried over MgSO4
9. concentrationconcentrated under reduced pressure

ORD record

ord-1966bb9a658246788d1a95b5f3c1c786

Source dataset

uspto-grants-2012_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08173831B2