Hydrogen Bromide → HCID 1514413, compound

HRID 344880Notes

Reaction equation

HRID 344880 reaction equation
[C:1]1([C@@H:7]2[CH2:12][N:11](S(C3C=CC(C)=CC=3)(=O)=O)[CH2:10][CH2:9][N:8]2S(C2C=CC(C)=CC=2)(=O)=O)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C1(O)C=CC=CC=1.Br.C(OC(C)C)(C)C>O>[C:1]1([C@@H:7]2[CH2:12][NH:11][CH2:10][CH2:9][NH:8]2)[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

6

Reactant 4

HCID 260Hydrogen BromideHCID 996PhenolHCID 7914Diisopropyl EtherHCID 53899556HCID 53899556, compound

Product 1

HCID 1514413HCID 1514413, compoundYield 66.7%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
120 °C

Procedure

A mixture of (R)-2-phenyl-1,4-bis(p-toluenesulphonyl)piperazine (10 g) and phenol (9.4 g) in 48% strength hydrobromic acid (100 cc) is heated with very vigorous stirring to a temperature in the region of 120° C. for 5 hours. After cooling to approximately 80° C., the reaction mixture is treated with water (250 cc), cooled to about 20° C. and washed with dichloromethane (5×100 cc). The aqueous phase is concentrated under reduced pressure (20 kPa) at approximately 80° C. The residue is taken up with ethyl acetate (100 cc), cooled to 5° C. and treated at between 5° and 20° C. with 30% strength aqueous sodium hydroxide (100 cc). The organic phase is separated and the aqueous phase extracted again with ethyl acetate (3×100 cc). The combined organic extracts are washed with 5N aqueous sodium hydroxide (4×20 cc), dried over magnesium sulphate, filtered and concentrated to dryness under reduced pressure (20 kPa) at approximately 30° C. The residue obtained is taken up with isopropyl ether (15 cc) at approximately 0° C., drained and washed at the same temperature with the same solvent (10 cc). (R)-2-Phenylpiperazine (2.3 g) is obtained in the form of a colorless solid, m.p. 117° C.

Workup

  1. temperatureis heated
  2. temperatureAfter cooling to approximately 80° C.
  3. temperaturecooled to about 20° C.
  4. washwashed with dichloromethane (5×100 cc)
  5. concentrationThe aqueous phase is concentrated under reduced pressure (20 kPa) at approximately 80° C
  6. temperaturecooled to 5° C.
  7. additiontreated at between 5° and 20° C. with 30% strength aqueous sodium hydroxide (100 cc)
  8. customThe organic phase is separated
  9. extractionthe aqueous phase extracted again with ethyl acetate (3×100 cc)
  10. washThe combined organic extracts are washed with 5N aqueous sodium hydroxide (4×20 cc)
  11. dry with materialdried over magnesium sulphate
  12. filtrationfiltered
  13. concentrationconcentrated to dryness under reduced pressure (20 kPa) at approximately 30° C
  14. customThe residue obtained
  15. washwashed at the same temperature with the same solvent (10 cc)

Sources & evidence

ORD record
ord-7ddc53ea8f634a7caba2c2f6618aa0e4
Source dataset
uspto-grants-1991_10
Patent number
US05053509

Reaction notes

Loading…