Sodium Hydroxide → (S)-3-Boc-2,2-dimethyloxazolidine-4-propanoic Acid

Temperature

23 °C

Sodium hydroxide (27 mL of a 4.0 M solution in H2O, 108 mmol, 3.0 equiv.) was added to a solution of (4S)-4-(2-methoxycarbonylethyl)-2.2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (prepared as described in Chida et al., J. Chem. Soc., Chem. Commun. 1992, 1064) (10.5 g, 36.5 mmol, 1 equiv.) in CH3OH (150 mL), and the resulting cloudy reaction mixture was stirred at 23° C. for 3.5 h. The mixture was concentrated under reduced pressure to ˜30 mL volume, and then was partitioned between 0.5 M HCl (150 mL) and EtOAc (2×150 mL). The combined organic layers were dried over MgSO4 and were gravity filtered. The filtrate was concentrated under reduced pressure and the residue dried under vacuum, to afford (4S)-4-(2′-carboxyethyl)-2,2-dimethyloxazolidine-3-carboxylic acid tert-butyl ester (10.0 g, 100% crude yield). This material was used without further purification: 1H NMR (CDCl3, mixture of rotamers) δ 1.49 (s), 1.57 (s), 1.60 (s), 1.84-2.05 (m), 2.39-2.41 (m), 3.71-3.74 (m), 3.91-4.05 (m).

1. customthe resulting cloudy reaction mixture
2. concentrationThe mixture was concentrated under reduced pressure to ˜30 mL volume
3. customwas partitioned between 0.5 M HCl (150 mL) and EtOAc (2×150 mL)
4. dry with materialThe combined organic layers were dried over MgSO4
5. filtrationfiltered
6. concentrationThe filtrate was concentrated under reduced pressure
7. customthe residue dried under vacuum

ORD record

ord-84af8911e53c4a42b93456f5176ed217

Source dataset

uspto-grants-2005_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06906198B1