1-Chloroethyl chloroformate → (3R)-3-benzyl-1-methanesulfonylpiperazine hydrochloride

HRID 581204Notes

Reaction equation

HRID 581204 reaction equation
C([N:8]1[CH2:13][CH2:12][N:11]([S:14]([CH3:17])(=[O:16])=[O:15])[CH2:10][C@H:9]1[CH2:18][C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1)C1C=CC=CC=1.[Cl:25]C(OC(Cl)C)=O>ClCCCl>[ClH:25].[CH2:18]([C@H:9]1[NH:8][CH2:13][CH2:12][N:11]([S:14]([CH3:17])(=[O:16])=[O:15])[CH2:10]1)[C:19]1[CH:20]=[CH:21][CH:22]=[CH:23][CH:24]=1

Participants

4

Reactant 2

HCID 5213051-Chloroethyl chloroformateHCID 54418760(2R)-1,2-dibenzyl-4-methanesulfonylpiperazine

Product 1

HCID 69942128(3R)-3-benzyl-1-methanesulfonylpiperazine hydrochlorideYield 41.9%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent2×

Conditions

Temperature
90 °C

Procedure

(2R)-1,2-Dibenzyl-4-methanesulfonylpiperazine (2.2 g; 6.4 mmol) was dissolved in dry 1,2-dichloroethane (20 ml) under an atmosphere of nitrogen. The mixture was placed on an ice-bath and a solution of α-chloroethyl chloroformate (1.0 g; 7.04 mmol) in dry 1,2-dichloroethane (10 ml) was added keeping the temperature between 0 and 5° C. When addition is complete stirring is continued for 15 minutes on the ice-bath. The reaction mixture is heated slowly to 90° C. on an oil-bath and heated at reflux temperature for 1 h. The major part of the solvent was allowed to evaporate and the residue was allowed to cool on an ice-bath. Methanol (20 ml) was added and the mixture was heated at reflux temperature for 1 h. The mixture was allowed to cool to ambient temperature, diethyl ether (30 ml) was slowly added and the mixture was stirred for 30 minutes. The solid was isolated by filtration, washed with diethyl ether, and dried to give 0.78 g of (3R)-3-benzyl-1-methanesulfonylpiperazine hydrochloride. M.p. 204-208° C.

Workup

  1. customThe mixture was placed on an ice-bath
  2. customthe temperature between 0 and 5° C
  3. additionWhen addition
  4. temperatureheated
  5. temperatureat reflux temperature for 1 h
  6. customto evaporate
  7. temperatureto cool on an ice-bath
  8. additionMethanol (20 ml) was added
  9. temperaturethe mixture was heated
  10. temperatureat reflux temperature for 1 h
  11. temperatureto cool to ambient temperature
  12. additiondiethyl ether (30 ml) was slowly added
  13. stirringthe mixture was stirred for 30 minutes
  14. customThe solid was isolated by filtration
  15. washwashed with diethyl ether
  16. customdried

Sources & evidence

ORD record
ord-87314c7fb8014f9b86eb2e19758320b1
Source dataset
uspto-grants-1999_07
Patent number
US05919777

Reaction notes

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