Ethanol → 1-(4-Fluorobenzyl)piperazine

HRID 4314

Reaction equation

HRID 4314 reaction equation
[F:1][C:2]1[CH:9]=[CH:8][C:5]([CH2:6]Cl)=[CH:4][CH:3]=1.C(O)C.[NH:13]1[CH2:18][CH2:17][NH:16][CH2:15][CH2:14]1>CCOCC>[F:1][C:2]1[CH:9]=[CH:8][C:5]([CH2:6][N:13]2[CH2:18][CH2:17][NH:16][CH2:15][CH2:14]2)=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 702Ethanol2×HCID 4837PiperazineHCID 96024-Fluorobenzyl chloride

Product 1

HCID 7965631-(4-Fluorobenzyl)piperazineYield 55.7%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Conditions

Temperature
20 °C

Procedure

A solution of 29 g of p-fluorobenzyl chloride in 50 g of reagent ethanol was added dropwise to a stirred solution of 34.5 g of piperazine in 150 g of reagent ethanol. A cold water bath was used to maintain the reaction temperature at 20° C. during the addition. The reaction mixture was stirred for an additional 11/2 hours and then added to 2 liters of ether. Precipitated piperazine hydrochloride was filtered off. The filtrate was concentrated to an oil, which was chromatographed on a silica column, the eluant being a mixture of CH2Cl2 /methanol/ammonium hydroxide in the ratio of 45:5:1. After concentration of appropriate fractions, 21.7 g of 1-(4-fluorobenzyl)piperazine were isolated as a colorless liquid (56% of theory).

Workup

  1. customA cold water bath was used
  2. additionduring the addition
  3. filtrationPrecipitated piperazine hydrochloride was filtered off
  4. concentrationThe filtrate was concentrated to an oil, which
  5. customwas chromatographed on a silica column
  6. additiona mixture of CH2Cl2 /methanol/ammonium hydroxide in the ratio of 45:5:1

Sources & evidence

ORD record
ord-3ac68fcac968481094ca4e6ef976f341
Source dataset
uspto-grants-1988_02
Patent number
US04725597

Linked notes

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