反应 #1253194

反应方程式

1-t-Butoxycarbonyl-3-oxopiperazine

potassium t-butoxide

1-(4-methylphenylsulfonyloxy)-2-fluoroethane

→

1-t-butoxycarbonyl-4-(2-fluoroethyl)-3-oxopiperazine

溶剂

DMF

反应条件

后处理

1. 1
   workup.STIRRINGstirring
2. 2
   workup.WAITcontinued at the same temperature for 24 hours
3. 3
   其他The solvent is removed
4. 4
   其他the residue partitioned between ethyl acetate and water
5. 5
   洗涤The organic phase is washed with water
6. 6
   浓缩concentrated
7. 7
   workup.DISSOLUTIONThe residue is dissolved in isopropanol
8. 8
   workup.ADDITIONdiluted with iso-hexane forming a precipitate which
9. 9
   其他is removed by filtration
10. 10
    其他The mixture is chromatographed (silica
11. 11
    洗涤eluting with
12. 12
    温度a gradient increasing in polarity from 0 to 50% isopropanol in iso-hexane)

实验过程

1-t-Butoxycarbonyl-3-oxopiperazine (21.6 g) is dissolved in dry DMF (500 ml) and potassium t-butoxide (24.2 g) is added. The mixture is stirred at 20-25° for 30 minutes, then 1-(4-methylphenylsulfonyloxy)-2-fluoroethane (J. Med. Chem., 23(9), 985-90 (1980), 25.9 g) is added and stirring continued at the same temperature for 24 hours. The solvent is removed and the residue partitioned between ethyl acetate and water. The organic phase is washed with water and concentrated. The residue is dissolved in isopropanol and diluted with iso-hexane forming a precipitate which is removed by filtration. The mixture is chromatographed (silica; eluting with a gradient increasing in polarity from 0 to 50% isopropanol in iso-hexane) to give 1-t-butoxycarbonyl-4-(2-fluoroethyl)-3-oxopiperazine.

来源