反应详情

温度

-50 °C

(S)-(+)-4-Phenyl-2-oxazolidinone (4.0 g, 24 mmol, Aldrich) was dissolved in dry THF (40 mL), and the solution was cooled to -50° C. and flushed with N2. Sodium hexamethyldisilazane (1.0M in THF, 25 mL, 25 mmol) was added slowly with stirring. The compound from step 7a (2.9 g, 24 mmol) was added slowly while maintaining the temperature at -50° C., and the mixture was stirred at this temperature for 1.5 hour. The mixture was allowed to warm to 0° C. and stirred for 1 hour. Saturated aqueous NH4Cl solution was added, the mixture was stirred for 10 minutes and the mixture was extracted with methylene chloride. The extract was dried over Na2SO4, filtered and the solvent was removed. The residue was chromatographed on silica gel, eluting with 2% methanol/methylene chloride, and the product was rechromatographed with 0.5% methanol/methylene chloride to give the title compound (1.69 g). MS m/ z 246 (M+H)+, 263 (M+NH4)+.

1. customflushed with N2
2. temperaturewhile maintaining the temperature at -50° C.
3. stirringthe mixture was stirred at this temperature for 1.5 hour
4. temperatureto warm to 0° C.
5. stirringstirred for 1 hour
6. stirringthe mixture was stirred for 10 minutes
7. extractionthe mixture was extracted with methylene chloride
8. dry with materialThe extract was dried over Na2SO4
9. filtrationfiltered
10. customthe solvent was removed
11. customThe residue was chromatographed on silica gel
12. washeluting with 2% methanol/methylene chloride
13. customthe product was rechromatographed with 0.5% methanol/methylene chloride