Benzaldehyde → (S)-2-(benzylamino)-2-cyclopropylacetic acid

(S)-2-amino-2-cyclopentylacetic acid (1) (66.0, 0.46 mol, 1.0 eq) was added in portions into 2N NaOH (230 mL, 0.46 mol, 1.0 eq) with stirring. After complete dissolution of the amino acid, benzaldehyde (49.0 g, 0.46 mol, 1.0 eq) was added all at once. The reaction mixture was allowed to stir at room temperature for 1 h. Sodium borohydride (17.5 g, 0.46 mol, 1.0 eq) was added slowly in portions at 0° C., and the reaction mixture was stirred at room temperature for 4 h. Then the reaction mixture was diluted with water (250 mL) and extracted twice with diethyl ether (250 mL). The clear aqueous layer was neutralized with 4N HCl (aq) to pH=7 and the white suspension were stirred at rt for 0.5 h. After filtration, the solid was washed with water (250 mL), the filter cake was dried to yield the product 2 (66 g, 59%) as a white solid.

1. additionwas added all at once
2. stirringto stir at room temperature for 1 h
3. stirringthe reaction mixture was stirred at room temperature for 4 h
4. extractionextracted twice with diethyl ether (250 mL)
5. stirringthe white suspension were stirred at rt for 0.5 h
6. filtrationAfter filtration
7. washthe solid was washed with water (250 mL)
8. customthe filter cake was dried

ORD record

ord-fb07d697028e4a44b71c229d64a3efdc

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09260478B2