反応 #1253194

反応方程式

1-t-Butoxycarbonyl-3-oxopiperazine

potassium t-butoxide

1-(4-methylphenylsulfonyloxy)-2-fluoroethane

→

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

溶媒

DMF

反応条件

後処理

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

実験手順

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.

出典