Hydrochloric Acid → HCID 24963431, compound

Participants

Reaction Conditions

Reaction Steps

129.9 g of (4S)-4-benzyl-3-[(2S)-3-(3-hydroxyphenyl)-2-isopropoxypropionyl]-1,3-oxazolidin-2-one was dissolved in 2 L of tetrahydrofuran, to which 140 mL of 30% hydrogen peroxide solution was added. Under cooling with ice, 700 mL of 1N lithium hydroxide solution was added dropwise, followed by stirring at 0° C. for 1 hour. To the reaction mixture was added 1N hydrochloric acid (500 mL), to which a sodium sulfite aqueous solution (10%, 500 mL) was then added slowly. The mixture was poured into a separating funnel to separate a tetrahydrofuran layer, followed by making the aqueous layer at pH 2 with 1N hydrochloric acid before extraction 3 times with ethyl acetate (1 L). The organic layers were combined and washed with a saturated sodium chloride solution (1.5 L) before drying the organic layer with anhydrous magnesium sulfate, followed by distilling off the solvent under a reduced pressure to obtain 130 g of (2S)-3-(3-hydroxyphenyl)-2-isopropoxypropionic acid. This compound was dissolved in 1 L of N,N-dimethylformamide, to which 67.8 g of potassium bicarbonate and 100 mL of ethyl iodide were sequentially added under cooling with ice, followed by stirring the reaction mixture at room temperature for 3 days. The reaction mixture was diluted with ethyl acetate, and washed sequentially with 1N hydrochloric acid and a saturated sodium chloride solution. The organic layer was dried with anhydrous magnesium sulfate, followed by distilling off the solvent under a reduced pressure. The residue was purified using silica gel column chromatography to obtain 61.8 g of the title compound in the form of colorless oily matter from a hexane-ethyl acetate (3:1)-eluted fraction.

Provenance & Evidence