Triphenylphosphine → 4-Benzenesulfonyl-6-(3-bromo-phenyl)-1-phenyl-piperazin-2-one

HRID 560118Notes

Reaction equation

HRID 560118 reaction equation
[C:1]1([S:7]([N:10]([CH2:21][CH:22]([C:24]2[CH:29]=[CH:28][CH:27]=[C:26]([Br:30])[CH:25]=2)O)[CH2:11][C:12]([NH:14][C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)=[O:13])(=[O:9])=[O:8])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.CCOC(/N=N/C(OCC)=O)=O>C(OC(=O)C)C>[C:1]1([S:7]([N:10]2[CH2:21][CH:22]([C:24]3[CH:29]=[CH:28][CH:27]=[C:26]([Br:30])[CH:25]=3)[N:14]([C:15]3[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=3)[C:12](=[O:13])[CH2:11]2)(=[O:9])=[O:8])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Participants

5

Reactant 3

HCID 11776TriphenylphosphineHCID 5462977Diethyl azodicarboxylateHCID 670010902-{benzenesulfonyl-[2-(3-bromo-phenyl)-2-hydroxy-ethyl]-amino}-N-phenyl-acetamide

Product 1

HCID 670004364-Benzenesulfonyl-6-(3-bromo-phenyl)-1-phenyl-piperazin-2-oneYield 89.4%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent2×

Procedure

At 0° C. to a solution of 2-{benzenesulfonyl-[2-(3-bromo-phenyl)-2-hydroxy-ethyl]-amino}-N-phenyl-acetamide (1.15 g) and triphenylphosphine (678 mg) in ethylacetate (10 mL) was added a solution of diethylazodicarboxylate (0.4 mL) in ethylacetate (5 mL) dropwise. After 15 min. the cooling bath was removed and the mixture was stirred at RT for 3 h. Additional amounts of triphenylphosphine (31 mg) and diethylazodicarboxylate (0.18 mL) were added, and stirring was continued for 1 h. The mixture was diluted with water and ethyl acetate, the phases were separated, and the inorganic one was extracted with ethyl acetate (×2). The organic layers were combined, washed with brine, dried (Na2SO4) and concentrated in vacuo. The crude product was purified by flash chromatography (SiO2, n-heptane/ethyl acetate 7:3) to give 4-benzenesulfonyl-6-(3-bromo-phenyl)-1-phenyl-piperazin-2-one (0.99 g, 89%) as a white foam, MS: 471.4 (M+H, 1Br)+.

Workup

  1. customAfter 15 min. the cooling bath was removed
  2. additionAdditional amounts of triphenylphosphine (31 mg) and diethylazodicarboxylate (0.18 mL) were added
  3. stirringstirring
  4. waitwas continued for 1 h
  5. additionThe mixture was diluted with water and ethyl acetate
  6. customthe phases were separated
  7. extractionthe inorganic one was extracted with ethyl acetate (×2)
  8. washwashed with brine
  9. dry with materialdried (Na2SO4)
  10. concentrationconcentrated in vacuo
  11. customThe crude product was purified by flash chromatography (SiO2, n-heptane/ethyl acetate 7:3)

Sources & evidence

ORD record
ord-3b4eb96377374f32acfd1dd662c942df
Source dataset
uspto-grants-2011_11
Patent number
US08063088B2

Reaction notes

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