Benzaldehyde → Benzyl 4-(2-aminoethyl)piperazine-1-carboxylate

HRID 965537Notes

Reaction equation

HRID 965537 reaction equation
[CH:1](=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[NH2:9][CH2:10][CH2:11][N:12]1C[CH2:16][NH:15][CH2:14][CH2:13]1.[OH2:18].[C:19]1([CH3:25])C=CC=CC=1>>[NH2:9][CH2:10][CH2:11][N:12]1[CH2:25][CH2:19][N:15]([C:16]([O:8][CH2:1][C:2]2[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=2)=[O:18])[CH2:14][CH2:13]1

Participants

5

Reactant 4

HCID 240BenzaldehydeHCID 962WaterHCID 1140TolueneHCID 8795Aminoethylpiperazine

Product 1

HCID 10890711Benzyl 4-(2-aminoethyl)piperazine-1-carboxylate

Procedure

8.21 g of benzaldehyde are added to a solution of 10 g of 1-(2-aminoethyl)piperazine in 125 ml of toluene and the mixture is refluxed for 3 hours, the water formed being removed by means of a Dean-Stark apparatus. The reaction mixture is concentrated under vacuum, the residue is taken up with 100 ml of DCM, 13.45 ml of DIPEA are added and 11.03 ml of benzyl chloroformate are added dropwise. The reaction mixture is stirred overnight at RT and concentrated under vacuum. The residue is taken up with a saturated solution of potassium hydrogensulfate and stirred vigorously for 4 hours at RT. The aqueous phase is washed with ether, rendered alkaline to pH 9-10 by the addition of concentrated NaOH, saturated by the addition of NaCl and extracted with chloroform, the organic phase is dried over sodium sulfate and the solvent is evaporated off under vacuum to give 18.78 g of the expected product, which is used as such in the next step.

Workup

  1. temperaturethe mixture is refluxed for 3 hours
  2. custombeing removed by means of a Dean-Stark apparatus
  3. concentrationThe reaction mixture is concentrated under vacuum
  4. additionare added
  5. addition11.03 ml of benzyl chloroformate are added dropwise
  6. concentrationconcentrated under vacuum
  7. stirringstirred vigorously for 4 hours at RT
  8. washThe aqueous phase is washed with ether
  9. additionby the addition of concentrated NaOH
  10. additionsaturated by the addition of NaCl
  11. extractionextracted with chloroform
  12. dry with materialthe organic phase is dried over sodium sulfate
  13. customthe solvent is evaporated off under vacuum

Sources & evidence

ORD record
ord-ce296651c34f410a9e2e13d0dc4aef8a
Source dataset
uspto-grants-1998_06
Patent number
US05773612

Reaction notes

Loading…