Piperazine → 1-(5-Bromopyridin-2-yl)piperazine

HRID 1600480Notes

Reaction equation

HRID 1600480 reaction equation
[Br:1][CH:2]1[CH2:7][NH:6][CH:5](Br)[CH2:4]N1.[NH:9]1[CH2:14][CH2:13][NH:12][CH2:11][CH2:10]1.[C:15](=O)([O-])[O-].[K+].[K+]>C(#N)C>[Br:1][C:2]1[CH:15]=[CH:4][C:5]([N:9]2[CH2:14][CH2:13][NH:12][CH2:11][CH2:10]2)=[N:6][CH:7]=1

Participants

5

Reactant 3

HCID 4837PiperazineHCID 11430Potassium CarbonateHCID 19614008HCID 19614008, compound

Product 1

HCID 164142271-(5-Bromopyridin-2-yl)piperazine

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

A solution of 2,5-dibromo piperazine (1.59 g, 8 mmole), and piperazine(1.45 g, 16 mmole), and potassium carbonate (6 g) in acetonitrile (50 mL) was heated at reflux for 48 h. The heating was discontinued and the solution allowed to cool to room temperature. The solid was filtered off and washed with acetonitrile (50 mL). The organics were concentrated to a tan solid. The product was purified by column chromatography on silica gel using dichloromethane:methanol:triethylamine (94:5:1) as eluent to provide (5-bromopyridin-2-yl)-piperazine as an offwhite solid (1.75 g, 95%). δH (300 MHz CDCl3) 1.75 (1H, br s), 2.95 (4H, m, piperaziny), 3.45 (4H, m, piperazinyl), 6.52 (1H, d, J=9.0), 7.51 (1H, dd, J=2.5 and 9.0), 8.17 (1H, d, J=2.4), ESMS 243 (MH+).

Workup

  1. temperatureat reflux for 48 h
  2. filtrationThe solid was filtered off
  3. washwashed with acetonitrile (50 mL)
  4. concentrationThe organics were concentrated to a tan solid
  5. customThe product was purified by column chromatography on silica gel

Sources & evidence

ORD record
ord-ad2bf359913e4c3e9037d9922670429e
Source dataset
uspto-grants-1999_11
Patent number
US05976497

Reaction notes

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