Ammonium Chloride → (S)-4-isopropyl-3-(3-phenylpropanoyl)oxazolidin-2-one

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Reaction Steps

68.3 ml (0.11 mol) of butyllithium (as a 1.6M solution in hexane) were added dropwise, at -78° C. and under an atmosphere of nitrogen, to a solution of 11.75 g (91.0 mmole) of 4(S)-isopropyl-2-oxazolidinone in 200 ml of anhydrous tetrahydrofuran; the mixture was then stirred for 30 minutes, after which a solution of 18.41 g (0.11 mole) of phenylpropionyl chloride in 100 ml of anhydrous tetrahydrofuran was added to it over a period of 10 minutes. The mixture was then stirred for 1 hour, after which it was mixed with a saturated aqueous solution of ammonium chloride and extracted with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate and the solvent was then removed by distillation under reduced pressure. The residue was purified by medium pressure column chromatography through silica gel (using a 1:3 by volume mixture of ethyl acetate and hexane as the eluent), followed by recrystallization from diisopropyl ether, to afford 20.12 g (yield 85%) of the title compound as white crystals, melting at 62°-63° C.

Provenance & Evidence