Toluene → [3-Oxo-5-(o-chlorophenyl)-1-cyclohexen-1-yl]-piperazine

HRID 980824Notes

Reaction equation

HRID 980824 reaction equation
O=[C:2]1[CH2:7][CH:6]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=2[Cl:14])[CH2:5][C:4](=[O:15])[CH2:3]1.[NH:16]1[CH2:21][CH2:20][NH:19][CH2:18][CH2:17]1.C1(C)C=CC=CC=1>O>[O:15]=[C:4]1[CH2:5][CH:6]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=2[Cl:14])[CH2:7][C:2]([N:16]2[CH2:21][CH2:20][NH:19][CH2:18][CH2:17]2)=[CH:3]1

Participants

5

Reactant 3

HCID 1140TolueneHCID 4837PiperazineHCID 8753605-(2-Chlorophenyl)cyclohexane-1,3-dione

Product 1

HCID 13520891[3-Oxo-5-(o-chlorophenyl)-1-cyclohexen-1-yl]-piperazine

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 24.0 g (0.108 mol) of 1,3-dioxo-5-(o-chlorophenyl)-cyclohexane, 28.4 g (0.33 mol) of anhydrous piperazine and 270 ml of toluene is heated at the boiling point under reflux for 5 hours, using a water separator. The toluene is distilled off, while still warm, in vacuo and the residue is dissolved in chloroform. This solution is extracted three times by shaking with water, to remove the excess piperazine, and dried with sodium sulphate. The concentrated solution is purified by means of column chromatography (corresponding to Example 2). Some of the fractions contain 6.5 g of the base [3-oxo-5-(o-chlorophenyl)-1-cyclohexen-1-yl]-piperazine in pure form, of melting point 159°-160° C., and another portion is still contaminated. The latter is purified by the oxalate: 6.2 g of a white salt of melting point 225°-227° C. (decomposition). After converting back into the base, a further 5.0 g are obtained. Total yield: 11.5 g (=36.7%). RF value: 0.38 (conditions corresponding to Example 1).

Workup

  1. temperatureis heated at the boiling point
  2. temperatureunder reflux for 5 hours
  3. distillationThe toluene is distilled off
  4. temperaturewhile still warm, in vacuo
  5. dissolutionthe residue is dissolved in chloroform
  6. extractionThis solution is extracted three times
  7. customto remove the excess piperazine
  8. dry with materialdried with sodium sulphate
  9. customThe concentrated solution is purified by means of column chromatography (corresponding to Example 2)
  10. customThe latter is purified by the oxalate
  11. customa further 5.0 g are obtained

Sources & evidence

ORD record
ord-0f0735542cee4ffb8a826f62b24f6d03
Source dataset
uspto-grants-1987_01
Patent number
US04639453

Reaction notes

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