Hydrochloric Acid → HCID 12052454, compound

To a stirred solution of methyl 2-hydroxy-3-cyclopropylbutanoate (0.62 g, 3.9 mmol) in MeOH (10 mL) was added aqueous NaOH (1.0 mL of a 5.5 M solution, 5.5 mmol). The mixture was stirred at ambient temperature for 18 h. The mixture was brought to pH 2 by the addition of 6 N aqueous HCl and solvents were removed under reduced pressure. The residue was dried under high vacuum for several hours. The residue was suspended in dichloromethane (15 mL) and stirred for 1 h. The solid was removed by filtration and the filtrate solvent was removed under reduced pressure. The residue was purified on a Chiralpak AD column using 90:10:0.1 hexanes:2-propanol:TFA as eluant. Fractions containing the first-eluting peak were pooled and the solvents were removed under reduced pressure to give 2(R)-hydroxy-3(S)-cyclopropylbutanoic acid as a white solid. HPLC RT=1.98 min (Method A); 1H NMR 400 MHz, CDCl3, 4.36 ppm (d, J=2.9 Hz, 1H), 1.18 ppm (m, 1H), 1.00 ppm (d, J=7 Hz, 3H), 0.86 ppm (m, 1H), 0.54 ppm (m, 2H), 0.23 ppm (m, 1H), 0.18 ppm (m, 1H)

1. customwere removed under reduced pressure
2. customThe residue was dried under high vacuum for several hours
3. stirringstirred for 1 h
4. customThe solid was removed by filtration
5. customthe filtrate solvent was removed under reduced pressure
6. customThe residue was purified on a Chiralpak AD column
7. additionFractions containing the first-eluting peak
8. customthe solvents were removed under reduced pressure

ORD record

ord-09e80ec0713f443fa39a072d7c90f407

Source dataset

uspto-grants-2003_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06528503B2