反応 #4410

反応方程式

p-fluorobenzyl chloride

ethanol

piperazine

ethanol

→

1-(4-fluorobenzyl)piperazine

収率 55.7%

溶媒

ether

—

reagent

—

reagent

反応条件

後処理

1. 1
   その他A cold water bath was used
2. 2
   workup.ADDITIONduring the addition
3. 3
   ろ過Precipitated piperazine hydrochloride was filtered off
4. 4
   濃縮The filtrate was concentrated to an oil, which
5. 5
   その他was chromatographed on a silica column
6. 6
   workup.ADDITIONa mixture of CH2Cl2 /methanol/ammonium hydroxide in the ratio of 45:5:1

実験手順

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).

出典