Pivaloyl chloride → (4S)-4-benzyl-3-(2-isopropoxyacetyl)oxazolidin-2-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A tetrahydrofuran (6 L) solution of 140 g of 2-isopropoxyacetic acid and 540 mL of triethylamine was cooled to −20° C., to which a tetrahydrofuran (100 mL) solution of 145 g of 2,2-dimethylpropanoyl chloride was added dropwise, followed by stirring the reaction mixture at −10 to −20° C. for 3 hours. The reaction mixture was cooled to −30° C., to which 80 g of anhydrous lithium chloride and then 225 g of (4S)-4-benzyl-1,3-oxazolidin-2-one was added, followed by stirring the reaction mixture overnight at room temperature. The reaction mixture was filtered and subjected to vacuum concentration. The residue was dissolved in 3 L of ethyl acetate, washed with a saturated sodium bicarbonate aqueous solution (1.5 L), and dried with anhydrous magnesium sulfate. The solvent was distilled off under a reduced pressure, and the residue was purified using silica gel column chromatography to obtain 196 g of the title compound in the form of colorless oily matter from a hexane-ethyl acetate (5:1→2:1)-eluted fraction.

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