Formaldehyde → (4S)-N-Boc-4-phenylmethyloxazolidin-5-one

HRID 2122032Notes

Reaction equation

HRID 2122032 reaction equation
[C:1]([O:5][C:6]([NH:8][C@H:9]([C:17]([OH:19])=[O:18])[CH2:10][C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[CH2:20]=O>C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1.C1(C)C=CC=CC=1>[C:1]([O:5][C:6]([N:8]1[C@@H:9]([CH2:10][C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)[C:17](=[O:19])[O:18][CH2:20]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

5

Reactant 2

HCID 712FormaldehydeHCID 77857L-Phenylalanine, N-[(1,1-dimethylethoxy)carbonyl]-

Product 1

HCID 11482799(4S)-N-Boc-4-phenylmethyloxazolidin-5-oneYield 72.2%

Reagents, catalysts & solvents 2

HCID 466102Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1)CatalystHCID 1140TolueneSolvent

Procedure

Tert-butoxycarbonyl-L-phenylalanine (20.00 g), paraformaldehyde (6.04 g) and pyridinium p-toluenesulfonate (0.95 g) were added to toluene (200 ml), and they were stirred under heating and reflux for 30 minutes. The reaction mixture was cooled to room temperature and washed with a saturated aqueous sodium hydrogencarbonate solution and saturated aqueous sodium chloride solution. The obtained toluene layer was dried over anhydrous sodium sulfate and then sodium sulfate was removed. The solvent was evaporated under reduced pressure. The concentrated solution was cooled to room temperature to crystallize the product. The crystals were separated and dried to obtain intended (4S)-N-tert-butoxycarbonyl-4-phenylmethyloxazolidin-5-one (15.10 g) (yield: 72%). 1H-NMR(CDCl3, 300 MHz) δ ppm: 1.51 (9H, s), 3.15 (d, 1H), 3.20-3.52 (m, 1H), 4.13-4.38 (m, 1H), 4.49 (bs, 1H), 5.06-5.38 (m, 1H), 7.12-7.22 (m, 2H), 7.22-7.35 (m, 3H)

Workup

  1. temperatureunder heating
  2. temperaturereflux for 30 minutes
  3. washwashed with a saturated aqueous sodium hydrogencarbonate solution and saturated aqueous sodium chloride solution
  4. dry with materialThe obtained toluene layer was dried over anhydrous sodium sulfate
  5. customsodium sulfate was removed
  6. customThe solvent was evaporated under reduced pressure
  7. temperatureThe concentrated solution was cooled to room temperature
  8. customto crystallize the product
  9. customThe crystals were separated
  10. customdried

Sources & evidence

ORD record
ord-ce2d8c34fea847f99f5c4baa92d50963
Source dataset
uspto-grants-2004_02
Patent number
US06696571B2

Reaction notes

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