HCID 18792069, compound → HCID 10714743, compound

HRID 2393808Notes

Reaction equation

HRID 2393808 reaction equation
[CH2:1]([Li])[CH2:2][CH2:3][CH3:4].[CH:6]([CH:9]1[CH:13]([C:14]([F:17])([F:16])[F:15])[O:12][C:11](=[O:18])[NH:10]1)([CH3:8])[CH3:7]>CCCCCC.C1COCC1>[CH:6]([C@H:9]1[C@H:13]([C:14]([F:15])([F:17])[F:16])[O:12][C:11](=[O:18])[N:10]1[C:11]([O:18][C@H:1]1[C@H:9]([CH:6]([CH3:8])[CH3:7])[CH2:13][CH2:14][C@@H:3]([CH3:4])[CH2:2]1)=[O:12])([CH3:8])[CH3:7]

Participants

5

Reactant 2

HCID 18792069HCID 18792069, compoundHCID 178418339Butyllithium

Product 1

HCID 10714743HCID 10714743, compound

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8058HexaneSolvent

Conditions

Temperature
25 °C

Procedure

n-Butyllithium (20 ml of a 10M solution in hexane) was added to a solution of (4RS),5SR)-4-isopropyl-5-trifluoromethyloxazolidin-2-one (35.8 g) in THF (600 ml) at -78° C., followed by stirring for 0.5 hours. (-)-Menthyl chloroformate (41 ml, freshly distilled) was added followed by continuation of stirring at -78° C. for 0.5 hours. The solution was warmed to 25° C. and the reaction quenched by addition of saturated aqueous sodium bicarbonate solution. The product was extracted into ether and washed with water and brine. The solution was dried (MgSO4) and the solvent removed under vacuum. The resulting oil crystallized upon standing to give a solid which was collected by filtration. The solid was washed with ether:hexane (1:1) and dried to give (4S,5R)-4-isopropyl-3-[(1R,3R,4S)-3-p-menthyloxycarbonyl]-5-trifluoromethyloxazolidin-2-one (23.15 g); m.p. 138°-140° C.; 1H NMR (300 MHz, DMSO): 5.51 (dd, 1H), 4.68 (m, 1H), 4.26 (m, 1H), 2.27 (m, 1H), 1.94 (d, 1H), 1.78 (m, 1H), 1.62 (d, 2H), 1.42 (m, 2H), 1.01 (dd, 2H), 0.95-0.84 (m, 24H), 0.71 (d, 3H); 19FNMR (376.5 MHz,DMSO): -76.9910; 99% d.e. (A further crop of 4.3 g (99% d.e.) was obtained from the mother liquor). [Note: the (4R,5S) isomer has m.p. 80°-82° C. and 19FNMR (376.5 MHz, DMSO): -77.0019.

Workup

  1. distillation(-)-Menthyl chloroformate (41 ml, freshly distilled)
  2. additionwas added
  3. stirringof stirring at -78° C. for 0.5 hours
  4. customthe reaction quenched by addition of saturated aqueous sodium bicarbonate solution
  5. extractionThe product was extracted into ether
  6. washwashed with water and brine
  7. dry with materialThe solution was dried (MgSO4)
  8. customthe solvent removed under vacuum
  9. customThe resulting oil crystallized
  10. customto give a solid which
  11. filtrationwas collected by filtration
  12. washThe solid was washed with ether:hexane (1:1)
  13. customdried

Sources & evidence

ORD record
ord-aa66a0f699c94f32982b95bcf23bb2d5
Source dataset
uspto-grants-1998_09
Patent number
US05808097

Reaction notes

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