Bromoacetyl chloride → HCID 70066743, compound

Participants

Reaction Steps

To a suspension of (4S)-4-(phenylthio)-L-proline (2.2 g., 10 mmole) in methylene chloride (50 ml., freshly distilled) is added bis(trimethylsilyl)acetamide (7.35 ml., 30 mmole). The reaction mixture is stirred at room temperature for 2 hours until it becomes almost clear. The reaction mixture is then cooled to -5° and bromoacetyl chloride (1.9 g., 1.0 ml., 12 mmole) is added dropwise keeping the temperature at -5°. After stirring overnight (-5° to room temperature), the reaction mixture is concentrated to about 50% of its volume, partitioned between saturated sodium bicarbonate/ethyl acetate and the layers are separated. The organic layer is extracted once more with saturated sodium bicarbonate. The combined aqueous layers are acidified to pH 2.0 with 10% potassium bisulfate and extracted with ethyl acetate (3×). The ethyl acetate fractions are combined, dried (Na2SO4) and concentrated to give 3.5 g. of (4S)-1-bromoacetyl)-4-(phenylthio)-L-proline as a viscous oil.

Provenance & Evidence