Acetone → (R)-methyl 2-(isopropylamino)butanoate

Methyl (2R)-2-amino-butanoate 1j (28.78 g, 0.19 mol) was dissolved in 200 mL of dichloromethane followed by the addition of acetone (11.96 g, 0.21 mol) and sodium acetate (30.76 g, 0.38 mol), stirred 3 hours. Sodium triacetoxyborohydride (59.61 g, 0.28 mol) was added. The reaction solution was stirred for 12 hours followed by the addition of 100 mL of 1 M hydrochloric acid and dropwise addition of saturated sodium carbonate solution to adjust pH to 8 to 9, extracted with dichloromethane (100 mL×3). The combined organic phase was washed with saturated sodium chloride solution (50 mL×3), then dried over anhydrous magnesium sulfate, filtered and the filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography to obtain the title compound methyl (2R)-2-(isopropylamino)butanoate 22a (16.40 g, yield: 55.0%) as a light yellow oil liquid.

1. stirringThe reaction solution was stirred for 12 hours
2. extractionextracted with dichloromethane (100 mL×3)
3. washThe combined organic phase was washed with saturated sodium chloride solution (50 mL×3)
4. dry with materialdried over anhydrous magnesium sulfate
5. filtrationfiltered
6. concentrationthe filtrate was concentrated under reduced pressure
7. customThe resulting residue was purified by silica gel column chromatography

ORD record

ord-b5089bc26bea439f89beae0b3a59cc42

Source dataset

uspto-grants-2014_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08691822B2