Hydrogen Bromide → Norchlorcyclizine

HRID 661318Notes

Reaction equation

HRID 661318 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]([C:24]2[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=2)[N:9]2[CH2:14][CH2:13][N:12](S(C3C=CC=CC=3)(=O)=O)[CH2:11][CH2:10]2)=[CH:4][CH:3]=1.Br.O>C(O)(=O)C>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]([CH:8]([C:24]2[CH:25]=[CH:26][CH:27]=[CH:28][CH:29]=2)[N:9]2[CH2:10][CH2:11][NH:12][CH2:13][CH2:14]2)=[CH:6][CH:7]=1

Participants

5

Reactant 3

HCID 260Hydrogen BromideHCID 962WaterHCID 251231441-(p-Chloro-α-phenylbenzyl)-4-(phenylsulfonyl)piperazine

Product 1

HCID 9340NorchlorcyclizineYield 99.7%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
27.5 °C

Procedure

Levorotatory (−)-1-[(4-chlorophenyl)phenylmethyl]-4-[(phenyl)sulfonyl]piperazine (100 gm) is added to 30% hydrobromic acid in acetic acid (271 ml). The suspension is stirred at 25-30° C. for 1 hour, heated to 60° C. and maintained for 4 hours. Water (1000 ml) is added to reaction mass and cooled to 25-30° C. The precipitate formed is filtered off and washed with water (250 ml). Toluene (500 ml) is added to the aqueous layer and basified with 50% aqueous solution of sodium hydroxide. Toluene layer is separated, distilled under reduced pressure and the residue left is recrystallised from boiling hexane (160 ml). The solution is filtered and allowed to recrystallise first at ambient temperature, and then in an ice bath. The product is filtered off, washed with hexane and dried to obtain 55 gm of levorotatory (−)-1-[(4-chloro phenyl)phenylmethyl]piperazine [M.R: 89-93° C.; [α]D25=−15.6 (c=1, methanol); Chiral Purity by HPLC: 99.7%].

Workup

  1. temperatureheated to 60° C.
  2. temperaturemaintained for 4 hours
  3. temperaturecooled to 25-30° C
  4. customThe precipitate formed
  5. filtrationis filtered off
  6. washwashed with water (250 ml)
  7. additionToluene (500 ml) is added to the aqueous layer and basified with 50% aqueous solution of sodium hydroxide
  8. customToluene layer is separated
  9. distillationdistilled under reduced pressure
  10. waitthe residue left
  11. customis recrystallised
  12. filtrationThe solution is filtered
  13. customto recrystallise first at ambient temperature
  14. filtrationThe product is filtered off
  15. washwashed with hexane
  16. customdried

Sources & evidence

ORD record
ord-e38b6b681f0a40e088a97ac1e3073b37
Source dataset
uspto-grants-2011_12
Patent number
US08084606B2

Reaction notes

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