Ammonium Chloride → (4R,5S)-4-methyl-5-phenyl-3-(3-phenyl-propionyl)oxazolidine-2-one

Participants

Reaction Conditions

Reaction Steps

A mechanically stirred solution of the resultant compound from Example 64 (10 g, 56.4 mmol) in dry THF (200 ml) under an atmosphere of nitrogen was treated with n-butyl-lithium in hexanes (1.05 equiv, 22.6 ml, 56.4 mmol, 2.5M) at -78° C. After stirring for an additional 20 min at -78° C., hydrocinnamoyl chloride (9.4 ml, 62 mmol, 1.1 equiv) was added and the reaction was allowed to warm to room temperature with stirring over 2 h. The clear reaction mixture was poured into 100 ml of saturated NH4Cl. The organic layer was removed and the resulting aqueous layer extracted three times with dichloromethane. The combined organic extracts were washed once with brine, dried (anhydrous sodium sulfate), filtered, and concentrated under reduced pressure to afford a crude solid. This material was recrystallized from hot ethyl acetate/hexane at 0°-5° C. overnight. First crop yielded 12.9 g, mp 99°-100° C. Second crop afforded 3.6 g. Total yield 16.5 g (95%).

Provenance & Evidence