Triethylamine → (S)-3-[2-(4-bromo-2-methoxy-phenyl)-acetyl]-4-isopropyl-oxazolidin-2-one

Participants

Reaction Conditions

Reaction Steps

Triethylamine (0.66 mL, 4.75 mmol) was added to a solution of (4-bromo-2-methoxy-phenyl)-acetic acid (1.02 g, 4.162 mmol) in THF (11 mL) in a first round bottom flask under argon atmosphere. The mixture was cooled at −78° C. and pivaloyl chloride (0.513 mL, 4.162 mmol) was added. After stirring for 10 minutes at −78° C., the reaction mixture was warmed to 0° C. and stirred for 30 minutes, then cooled again at −78° C. In second round bottom flask (S)-4-isopropyl-2-oxazolidinone (591.2 mg, 4.577 mmol) was dissolved in THF (20 mL) and cooled to −78° C., and n-BuLi (2.5 M in hexane, 2.0 mL, 4.99 mmol) was added. After stirring for 10 minutes at −78° C., the metallated oxazolidinone mixture in the second flask was added to the mixed anhydride in the first flask at −78° C. The reaction mixture was stirred for 4 hours at 0° C., then at room temperature for 18 hours. A saturated solution of NH4Cl was added, and the mixture was extracted with EtOAc. The combined organic extracts were washed with brine, dried over Na2SO4, filtered and evaporated under reduced pressure. The residue was purified via flash chromatography (hexane/EtOAc, 84/16) to give 1.13 g (77% yield) of (S)-3-[2-(4-bromo-2-methoxy-phenyl)-acetyl]-4-isopropyl-oxazolidin-2-one.

Provenance & Evidence