p-Bromobenzenesulfonyl chloride → 4-(4-BOC-piperazinosulfonyl)bromobenzene

HRID 1644723Notes

Reaction equation

HRID 1644723 reaction equation
C(N(CC)CC)C.[C:8]([O:12][C:13]([N:15]1[CH2:20][CH2:19][NH:18][CH2:17][CH2:16]1)=[O:14])([CH3:11])([CH3:10])[CH3:9].[Br:21][C:22]1[CH:27]=[CH:26][C:25]([S:28](Cl)(=[O:30])=[O:29])=[CH:24][CH:23]=1>O1CCCC1>[C:8]([O:12][C:13]([N:15]1[CH2:20][CH2:19][N:18]([S:28]([C:25]2[CH:26]=[CH:27][C:22]([Br:21])=[CH:23][CH:24]=2)(=[O:30])=[O:29])[CH2:17][CH2:16]1)=[O:14])([CH3:11])([CH3:9])[CH3:10]

Participants

5

Reactant 3

HCID 7396p-Bromobenzenesulfonyl chlorideHCID 8471TriethylamineHCID 143452tert-Butyl piperazine-1-carboxylate

Product 1

HCID 166655764-(4-BOC-piperazinosulfonyl)bromobenzeneYield 92.1%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

Triethylamine (0.94 mL, 6.71 mmol) was added to a stirred reaction mixture of N-tert-butoxycarbonyl piperazine (0.50 g, 2.68 mmol) in tetrahydrofuran (6 mL) at 0° C., then the reaction mixture was stirred at room temperature for 15 minutes. A solution of 4-bromo-benzenesulfonyl chloride (0.686 g, 2.68 mmol) in tetrahydrofuran (4 mL) was added to the reaction mixture and stirring continued for another 2 hours. Tetrahydrofuran was evaporated off under reduced pressure, then the reaction mixture was diluted with ethyl acetate (20 mL). The inorganic materials were filtered off through a celite bed. The filtrate was washed with 2 N aqueous HCl (5 mL), dried over anhydrous sodium sulfate and concentrated in vacuo to yield 1.00 g (92%) of 4-(4-bromo-benzenesulfonyl)-piperazine-1-carboxylic acid tert-butyl ester as a white solid, which was used in the next step without further purification. MS cald. for C15H21BrN2O4S [(M+NH4)+] 422, obsd. 422.1.

Workup

  1. stirringstirring
  2. waitcontinued for another 2 hours
  3. customTetrahydrofuran was evaporated off under reduced pressure
  4. additionthe reaction mixture was diluted with ethyl acetate (20 mL)
  5. filtrationThe inorganic materials were filtered off through a celite bed
  6. washThe filtrate was washed with 2 N aqueous HCl (5 mL)
  7. dry with materialdried over anhydrous sodium sulfate
  8. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-d63d745ea88a4ec491bf770fbd13c220
Source dataset
uspto-grants-2012_02
Patent number
US08124629B2

Reaction notes

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