Triethylamine → Ethyl 1,4-dibenzylpiperazine-2-carboxylate

HRID 1769688Notes

Reaction equation

HRID 1769688 reaction equation
[CH2:1]([NH:8][CH2:9][CH2:10][NH:11][CH2:12][C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.Br[CH:20]([CH2:26]Br)[C:21]([O:23][CH2:24][CH3:25])=[O:22].C(N(CC)CC)C>C1(C)C=CC=CC=1>[C:13]1([CH2:12][N:11]2[CH2:10][CH2:9][N:8]([CH2:1][C:2]3[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=3)[CH2:26][CH:20]2[C:21]([O:23][CH2:24][CH3:25])=[O:22])[CH:14]=[CH:15][CH:16]=[CH:17][CH:18]=1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 8793BenzathineHCID 97945Ethyl 2,3-dibromopropionate

Product 1

HCID 2736402Ethyl 1,4-dibenzylpiperazine-2-carboxylateYield 100%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent2×

Conditions

Temperature
80 °C

Procedure

To a solution of 1 (N,N'-dibenzylethylenediamine, 76.8 g, 0.296 mol) in toluene (240 mL) at 40° C. with mechanical stirring was added dropwise a solution of 2 (ethyl 2,3-dibromopropionate, 71.0 g, 0.296 mol) and triethylamine (84 mL, 0.60 mol) in 75 mL of toluene such that the temperature remained below 80° C. The mixture was stirred at 80° C. for 2.5 hours, then cooled. The resulting mixture was filtered, and the filtrate partitioned with 200 mL of water. The organic extract was dried with Na2SO4, and solvent removed in vacuo to yield an amber oil (3, 105 g, 100% yield). This material was used as is in the subsequent step, thus analysis was not obtained.

Workup

  1. customremained below 80° C
  2. temperaturecooled
  3. filtrationThe resulting mixture was filtered
  4. customthe filtrate partitioned with 200 mL of water
  5. extractionThe organic extract
  6. dry with materialwas dried with Na2SO4, and solvent
  7. customremoved in vacuo
  8. customto yield an amber oil (3, 105 g, 100% yield)
  9. customwas not obtained

Sources & evidence

ORD record
ord-74f2428c2dca472db219082ade1259ab
Source dataset
uspto-grants-1995_01
Patent number
US05382584

Reaction notes

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