Boron trifluoride etherate → 4-tert-Butyl 3-methyl (3S)-morpholine-3,4-dicarboxylate

HRID 325243Notes

Reaction equation

HRID 325243 reaction equation
[CH3:1][O:2][C:3]([C@@H:5]1[CH2:10][O:9][CH2:8][CH:7](O)[N:6]1[C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])=[O:4].C([SiH](CC)CC)C.B(F)(F)F.CCOCC>C(Cl)Cl>[CH3:1][O:2][C:3]([C@@H:5]1[CH2:10][O:9][CH2:8][CH2:7][N:6]1[C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])=[O:4]

Participants

5

Reactant 3

HCID 8000Boron trifluoride etherateHCID 12052TriethylsilaneHCID 20648540HCID 20648540, compound

Product 1

HCID 206485414-tert-Butyl 3-methyl (3S)-morpholine-3,4-dicarboxylateYield 41%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A solution of example 1109C (522 mg, 2.0 mmol) in 4 mL of methylene chloride was cooled in an ice/acetone bath and triethylsilane (1.6 mL, 10.0 mmol) was added. The solution was then treated with a solution of boron trifluoride etherate (0.27 mL, 2.2 mmol) in 1 mL of methylene chloride. After stirring 30 minutes, the bath was removed and stirring continued for 30 minutes and the mixture was quenched by the addition of 2M aqueous sodium carbonate. The mixture was diluted with water and methylene choride and the layers separated. The aqueous layer was extracted with 2 portions of methylene chloride and the combined organic layers were dried, filtered and concentrated. The residue was purified by column chromatography on silica gel (40 g, 20% ethyl acetate/hexanes) to provide 200 mg (41%) of the title compound. MS (DCI, NH3): 246 (MH+); 263 (M+NH4)+.

Workup

  1. customthe bath was removed
  2. stirringstirring
  3. waitcontinued for 30 minutes
  4. customthe mixture was quenched by the addition of 2M aqueous sodium carbonate
  5. additionThe mixture was diluted with water and methylene choride
  6. customthe layers separated
  7. extractionThe aqueous layer was extracted with 2 portions of methylene chloride
  8. customthe combined organic layers were dried
  9. filtrationfiltered
  10. concentrationconcentrated
  11. customThe residue was purified by column chromatography on silica gel (40 g, 20% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-4c5d48531d584125850e67c9c4dbdb07
Source dataset
uspto-grants-2001_04
Patent number
US06221865B1

Reaction notes

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