1-(2-Methoxyphenyl)piperazine → o-(1-Piperazinyl)phenol dihydrobromide
Reaction equation
[BrH:1].Br.N1CCNCC1.Br.Br.OC1C=CC(N2CCNCC2)=CC=1.C[O:25][C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][C:27]=1[N:32]1[CH2:37][CH2:36][NH:35][CH2:34][CH2:33]1>>[BrH:1].[BrH:1].[OH:25][C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][C:27]=1[N:32]1[CH2:37][CH2:36][NH:35][CH2:34][CH2:33]1Participants
Procedure
4-(=- 1)piperazine dihydrobromide may be prepared in the following manner: the experiment is carried out as in Example 8 for the preparation of 4-(4hydroxyphenyl)piperazine dihydrobromide, starting with 4-(2-methoxypheny)piperazine (25 g) and 47% aqueous solution of hydrdromic acid (360 cc). The mixture is heated at boiling point for 9 hours, the cooled to a temperature close to 20° C. Stirring is maintained for 15 hours at this temperature, then the mixture is concentrated at 40° C underreduced pressure (20 mm g; 2.7 kPa). The residual oil is redissolved in acetonitrile (40 cc) and isopropyl oxide (40 cc); the precipitate formed is separated by filtration, washed with oxide (2×50 cc). 4-(2-Hydroxyphenyl)piperazine dihydrobromide (m.p.: 235° C.) (18g) is obtained, which is used in the crude state in the subsequent syntheses.
Workup
- temperatureThe mixture is heated
- customfor 9 hours
- temperaturethe cooled to a temperature
- customclose to 20° C
- temperatureis maintained for 15 hours at this temperature
- concentrationthe mixture is concentrated at 40° C underreduced pressure (20 mm g; 2.7 kPa)
- dissolutionThe residual oil is redissolved in acetonitrile (40 cc)
- customthe precipitate formed
- customis separated by filtration
- washwashed with oxide (2×50 cc)
Sources & evidence
- ORD record
- ord-5bb11109698744f8b57df7930ade6bb4
- Source dataset
- uspto-grants-1991_06
- Patent number
- US05021420
Reaction notes
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