Carbon tetrabromide → 1,4-Bis(t-butoxycarbonyl)-2-(2-bromoethyl)piperazine

HRID 352834Notes

Reaction equation

HRID 352834 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[CH2:10][CH:9]1[CH2:21][CH2:22]O)=[O:7])([CH3:4])([CH3:3])[CH3:2].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C(Br)(Br)(Br)[Br:44]>C(Cl)Cl>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[CH2:10][CH:9]1[CH2:21][CH2:22][Br:44])=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

5

Reactant 3

HCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 22710988di-tert-Butyl 2-(2-hydroxyethyl)piperazine-1,4-dicarboxylate

Product 1

HCID 227107281,4-Bis(t-butoxycarbonyl)-2-(2-bromoethyl)piperazine

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

In methylene chloride (70 ml) were dissolved 1,4-bis(tert-butoxycarbonyl)-2-(2-hydroxyethyl)piperazine (2.01 g) and triphenylphosphine (1.98 g). Under ice cooling, carbon tetrabromide (3.07 g) was added to the resulting solution, followed by stirring at room temperature for 2.5 hours. The reaction mixture was extracted with a 10% aqueous solution of sodium thiosulfate. The organic layer was washed with saturated aqueous NaCl solution, dried over anhydrous sodium sulfate an distilled under reduced pressure to remove the solvent. The residue was subjected to column chromatography (hexane:ethyl acetate=4:1) using as a carrier silica gel, whereby the title compound (2.20 g) was obtained as colorless powder.

Workup

  1. extractionThe reaction mixture was extracted with a 10% aqueous solution of sodium thiosulfate
  2. washThe organic layer was washed with saturated aqueous NaCl solution
  3. dry with materialdried over anhydrous sodium sulfate
  4. distillationan distilled under reduced pressure
  5. customto remove the solvent
  6. customwas obtained as colorless powder

Sources & evidence

ORD record
ord-39831b8d51d94294b2ce91658b8f3627
Source dataset
uspto-grants-2004_06
Patent number
US06747023B1

Reaction notes

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