Piperazine → 2-(Piperazin-1-yl)-1,3-benzoxazole

HRID 2293990Notes

Reaction equation

HRID 2293990 reaction equation
[NH:1]1[CH2:6][CH2:5][NH:4][CH2:3][CH2:2]1.Cl[C:8]1[O:9][C:10]2[CH:16]=[CH:15][CH:14]=[CH:13][C:11]=2[N:12]=1.C(=O)([O-])[O-].[K+].[K+].[I-].[K+]>C(#N)C>[O:9]1[C:10]2[CH:16]=[CH:15][CH:14]=[CH:13][C:11]=2[N:12]=[C:8]1[N:1]1[CH2:6][CH2:5][NH:4][CH2:3][CH2:2]1

Participants

6

Reactant 4

HCID 4837PiperazineHCID 4875Potassium IodideHCID 11430Potassium CarbonateHCID 119862-Chlorobenzoxazole

Product 1

HCID 6478182-(Piperazin-1-yl)-1,3-benzoxazoleYield 57.1%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

In 200 ml of acetonitrile were dissolved 33.6 g (0.39 mole) of piperazine and 10.0 g (0.065 mole) of 2-chlorobenzoxazole, and 9.0 g (0.065 mole) of potassium carbonate and a catalytic amount of potassium iodide were added thereto. The mixture was refluxed by heating for 11 hours under stirring. The mixture was cooled to room temperature and then filtered. The filtrate was concentrated under reduced pressure, and the residue was applied to silica gel column chromatography (the eluent used was a mixture of chloroform:methanol=9:1) to obtain 7.54 g of 1-(2-benzoxazolyl)piperazine as white crystals.

Workup

  1. temperatureThe mixture was refluxed
  2. temperatureby heating for 11 hours
  3. filtrationfiltered
  4. concentrationThe filtrate was concentrated under reduced pressure
  5. additiona mixture of chloroform

Sources & evidence

ORD record
ord-e886c5a785014f8aadb7e9d33861b694
Source dataset
uspto-grants-1997_11
Patent number
US05688791

Reaction notes

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