Ethylenediamine → 2-Thiophen-2-yl-piperazine

HRID 248478Notes

Reaction equation

HRID 248478 reaction equation
[CH2:1]([NH2:4])[CH2:2][NH2:3].[S:5]1[CH:9]=[CH:8][CH:7]=[C:6]1[C:10](=O)[CH:11]=O.[BH4-].[Na+]>C(O)C>[S:5]1[CH:9]=[CH:8][CH:7]=[C:6]1[CH:10]1[CH2:11][NH:4][CH2:1][CH2:2][NH:3]1

Participants

5

Reactant 3

HCID 3301EthylenediamineHCID 4311764Sodium borohydrideHCID 52722142-Oxo-2-(thiophen-2-yl)acetaldehyde

Product 1

HCID 27717262-Thiophen-2-yl-piperazineYield 56.7%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

A solution of 8.2 g of ethylenediamine in 250 ml of ethanol was added to a solution of 17.64 g of the above aldehyde in 250 ml of ethanol at 0° C. This mixture was stirred at room temperature for 1.5 hours, recooled to 0° C. and 9.6 g of sodium borohydride was added. This mixture was stirred overnight, quenched with water and the ethanol removed. The residue was extracted with dichloromethane, washed with water, dried and evaporated. The residue was crystallized with ether-hexane, giving 12 g of 2-(2-thienyl)piperazine.

Workup

  1. customrecooled to 0° C.
  2. stirringThis mixture was stirred overnight
  3. customquenched with water
  4. customthe ethanol removed
  5. extractionThe residue was extracted with dichloromethane
  6. washwashed with water
  7. customdried
  8. customevaporated
  9. customThe residue was crystallized with ether-hexane

Sources & evidence

ORD record
ord-03c5b5351a4a4e46b13c65bdb72b76ca
Source dataset
uspto-grants-1993_05
Patent number
US05210193

Reaction notes

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