1-Chloroethyl chloroformate → Ethyl 1-benzylpiperazine-2-carboxylate

HRID 2065757Notes

Reaction equation

HRID 2065757 reaction equation
[CH2:1]([N:8]1[CH2:13][CH2:12][N:11](CC2C=CC=CC=2)[CH2:10][CH:9]1[C:21]([O:23][CH2:24][CH3:25])=[O:22])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.ClC(OC(Cl)C)=O>ClC(Cl)C>[CH2:24]([O:23][C:21]([CH:9]1[CH2:10][NH:11][CH2:12][CH2:13][N:8]1[CH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1)=[O:22])[CH3:25]

Participants

4

Reactant 2

HCID 5213051-Chloroethyl chloroformateHCID 2736402Ethyl 1,4-dibenzylpiperazine-2-carboxylate

Product 1

HCID 10682021Ethyl 1-benzylpiperazine-2-carboxylate

Reagents, catalysts & solvents 1

HCID 63651,1-DichloroethaneSolvent2×

Conditions

Temperature
0 °C

Procedure

Under argon at 0° C., to a solution of ethyl 1,4-dibenzylpiperazine-2-carboxylate (10 g) in dichloroethane (40 mL) a solution of 1-chloroethyl chloroformate (4.73 mL) in dichloroethane (14 mL) was added dropwise over a period of 10 min. The reaction mixture was stirred for 15 minutes at 0° C., and then heated to reflux overnight. The solvent was evaporated and the crude material was dissolved in ethanol and heated at reflux overnight. The solvent was evaporated and the residue was dissolved in water and extracted with diethyl ether (×2) and CH2Cl2 (×2). A saturated solution of NaHCO3 was then added to the water phase, and the inorganic phase was extracted with CH2Cl2 (×2). The organic layers were then combined, washed with brine, dried (Na2SO4), filtered and concentrated to give 1-benzyl-piperazine-2-carboxylic acid ethyl ester as crude product, MS: 248.9 ([M+H]+).

Workup

  1. temperatureheated
  2. temperatureto reflux overnight
  3. customThe solvent was evaporated
  4. dissolutionthe crude material was dissolved in ethanol
  5. temperatureheated
  6. temperatureat reflux overnight
  7. customThe solvent was evaporated
  8. dissolutionthe residue was dissolved in water
  9. extractionextracted with diethyl ether (×2) and CH2Cl2 (×2)
  10. additionA saturated solution of NaHCO3 was then added to the water phase
  11. extractionthe inorganic phase was extracted with CH2Cl2 (×2)
  12. washwashed with brine
  13. dry with materialdried (Na2SO4)
  14. filtrationfiltered
  15. concentrationconcentrated

Sources & evidence

ORD record
ord-d73ac80ff3de402681e02e2830bf7951
Source dataset
uspto-grants-2012_10
Patent number
US08288541B2

Reaction notes

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