Hydrogen Bromide → p-(1-Piperazinyl)phenol dihydrobromide

HRID 1493259Notes

Reaction equation

HRID 1493259 reaction equation
Cl.Cl.C[O:4][C:5]1[CH:10]=[CH:9][C:8]([N:11]2[CH2:16][CH2:15][NH:14][CH2:13][CH2:12]2)=[CH:7][CH:6]=1.[BrH:17]>>[BrH:17].[BrH:17].[OH:4][C:5]1[CH:6]=[CH:7][C:8]([N:11]2[CH2:16][CH2:15][NH:14][CH2:13][CH2:12]2)=[CH:9][CH:10]=1

Participants

3

Reactant 2

HCID 260Hydrogen BromideHCID 27237001-(4-Methoxyphenyl)-piperazine, dihydrochloride

Product 1

HCID 2723591p-(1-Piperazinyl)phenol dihydrobromide

Conditions

Temperature
20 °C

Procedure

1-(4-Hydroxyphenyl)piperezine dihydrobromide may be prepared in the following manner: a 47% aqueous solution of hydrobromic acid (720 cc) is added, over 30 minutes and at a temperature of about 20° C., to 4-(4-methoxyphenyl)piperazine dihydrochloride (70 g). The mixture is heated at boiling point for 4 hours then cooled to a temperature of about 20° C. Stirring is continued for 15 hours at this temperature, then the mixture is concentrated at 40° C. under reduced pressure (20 mm Hg; 2.7 kPa). The residual oil is redissolved in acetonitrile (300 cc). The precipitate formed is separated by filtration, washed with acetonitrile (2 x 50 cc) and diisopropyl ether (2 x 100 cc). 4-(4-Hydroxyphenyl)piperazine dihydrobromide (85.2 g) (m.p. greater than 260° C.) is obtained and used in the crude state in the subsequent syntheses.

Workup

  1. temperatureThe mixture is heated
  2. customfor 4 hours
  3. concentrationthe mixture is concentrated at 40° C. under reduced pressure (20 mm Hg; 2.7 kPa)
  4. dissolutionThe residual oil is redissolved in acetonitrile (300 cc)
  5. customThe precipitate formed
  6. customis separated by filtration
  7. washwashed with acetonitrile (2 x 50 cc) and diisopropyl ether (2 x 100 cc)

Sources & evidence

ORD record
ord-1ab375b6f0854b349f003e459eaddb67
Source dataset
uspto-grants-1991_06
Patent number
US05021420

Reaction notes

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