Ammonium Chloride → 3-(trans-3-cyclopropyl-2-propenoyl)-4-(R)-phenyl-2-oxazolidinone

Temperatur

-78 °C

(R)-(-)-4-Phenyl-2-oxazolidinone (39.12 g, 0.240 mmol, Aldrich) was dissolved in THF (600 mL), and the solution was cooled to -78° C. and flushed with N2. n-Butyllithium (2.5M in THF, 96.0 mL, 0.240 mmol) was introduced over 25 minutes. The compound from step 1b (0.276 mmol) was added while maintaining the temperature at -78° C., and the mixture was stirred at this temperature for half an hour. The mixture was stirred as it was allowed to warm to room temperature. Saturated aqueous NH4Cl solution was added, the mixture was stirred for 10 minutes and the THF was removed under reduced pressure. The residue was dissolved in ethyl acetate, and the solution was washed with water, 5% aqueous NaHCO3 and brine, then dried over Na2SO4. The solvent was removed to afford the title compound, which was recrystallized from ethyl acetate:hexane to give the title product (54.660 g, 89% yield). MS m/z 258 (M+H)+, 275 (M+NH4)+.

1. customflushed with N2
2. temperaturewhile maintaining the temperature at -78° C.
3. stirringThe mixture was stirred as it
4. temperatureto warm to room temperature
5. stirringthe mixture was stirred for 10 minutes
6. customthe THF was removed under reduced pressure
7. dissolutionThe residue was dissolved in ethyl acetate
8. washthe solution was washed with water, 5% aqueous NaHCO3 and brine
9. dry with materialdried over Na2SO4
10. customThe solvent was removed

ORD-Eintrag

ord-31376b25ebb54a0d8fde7aaac9d2e2e3

Quelldatensatz

uspto-grants-1997_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05668164