Sodium Sulfite → (4R)-4-benzyl-3-[(2R)-2-bromo-5-(4-methoxyphenyl)pentanoyl]-1,3-oxazolidin-2-one

HRID 1360220Notes

Reaction equation

HRID 1360220 reaction equation
[CH2:1]([C@@H:8]1[CH2:12][O:11][C:10](=[O:13])[N:9]1[C:14](=[O:27])[CH2:15][CH2:16][CH2:17][CH2:18][C:19]1[CH:24]=[CH:23][C:22]([O:25][CH3:26])=[CH:21][CH:20]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.OS(C(F)(F)F)(=O)=O.C(BCCCC)CCC.C(N(C(C)C)CC)(C)C.[Br:54]N1C(=O)CCC1=O.S([O-])([O-])=O.[Na+].[Na+]>ClCCl.C(Cl)(Cl)Cl>[CH2:1]([C@@H:8]1[CH2:12][O:11][C:10](=[O:13])[N:9]1[C:14](=[O:27])[C@H:15]([Br:54])[CH2:16][CH2:17][CH2:18][C:19]1[CH:24]=[CH:23][C:22]([O:25][CH3:26])=[CH:21][CH:20]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

8

Reactant 5

HCID 24437Sodium SulfiteHCID 67184N-bromobutanimideHCID 81531DiisopropylethylamineHCID 57880330(4R)-4-benzyl-3-[5-(4-methoxyphenyl)pentanoyl]-1,3-oxazolidin-2-oneHCID 178440534HCID 178440534, compound

Product 1

HCID 57880346(4R)-4-benzyl-3-[(2R)-2-bromo-5-(4-methoxyphenyl)pentanoyl]-1,3-oxazolidin-2-oneYield 52.9%

Reagents, catalysts & solvents 2

HCID 6212ChloroformSolventHCID 6344DichloromethaneSolvent2×

Conditions

Temperature
-78 °C

Procedure

(4R)-4-Benzyl-3-[5-(4-methoxyphenyl)pentanoyl]-1,3-oxazolidin-2-one (Reference Example 19) (1.4 g) was dissolved in dichloromethane (25 ml), and dibutylborane triflate (1M, 8.3 ml) and diisopropylethylamine (1.6 ml) were added thereto under ice-cooling. After 30 minutes, the reaction mixture was cooled to −78° C. and added dropwise to a solution of N-bromosuccinimide (NBS) (1.1 g) in dichloromethane (25 ml) which had been cooled to −78° C., via a cannula. After 2 hours, an aqueous sodium sulfite solution was added thereto and the resulting mixture was stirred at room temperature for 30 minutes. Chloroform was added to the reaction mixture to effect separation and extraction. The organic layer was dried, concentrated, and then the residue was purified by a silica gel chromatography (150 g, ethyl acetate:hexane=1:4) to obtain (4R)-4-benzyl-3-[(2R)-2-bromo-5-(4-methoxyphenyl)pentanoyl]-1,3-oxazolidin-2-one (0.9 g).

Workup

  1. temperatureunder ice-cooling
  2. temperaturehad been cooled to −78° C., via a cannula
  3. waitAfter 2 hours
  4. customseparation and extraction
  5. customThe organic layer was dried
  6. concentrationconcentrated
  7. customthe residue was purified by a silica gel chromatography (150 g, ethyl acetate:hexane=1:4)

Sources & evidence

ORD record
ord-0478151a685441f282ed5a6942379309
Source dataset
uspto-grants-2011_02
Patent number
US07879843B2

Reaction notes

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