(2R)-2-Bromopropanoic acid → (S)-2-(Acetylthio)-propanoic Acid

To a light green solution of potassium thioacetate (3.94 g, 34.5 mmol) in acetonitrile (150 ml) was added a solution of (R)-2-bromopropanoic acid (4.8 g, 31 mmol) in acetonitrile (12 ml) at room temperature under an argon atomosphere. The resulting white slurry was stirred at room temperature for 2 hours then filtered. The filtrate was concentrated in vacuo. The residue was diluted in ethyl acetate (100 ml), washed with a 10% aqueous solution of potassium bisulfate (50 ml) and brine, dried (sodium sulfate), and concentrated in vacuo. The crude product (4.61 g) was purified by flash chromatography (60 g - Merck silica gel, 1:45:54 acetic acid/ethyl acetate/hexane) to afford 3.7 g of the title product as a light yellow oil; [α]D =-114° (c=0.50, methanol).

1. filtrationthen filtered
2. concentrationThe filtrate was concentrated in vacuo
3. additionThe residue was diluted in ethyl acetate (100 ml)
4. washwashed with a 10% aqueous solution of potassium bisulfate (50 ml) and brine
5. dry with materialdried (sodium sulfate)
6. concentrationconcentrated in vacuo
7. customThe crude product (4.61 g) was purified by flash chromatography (60 g - Merck silica gel, 1:45:54 acetic acid/ethyl acetate/hexane)

ORD record

ord-554dd3814e874b69a67ab2020c1d763b

Source dataset

uspto-grants-1997_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05672599