반응 #1253194

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1-t-Butoxycarbonyl-3-oxopiperazine

potassium t-butoxide

1-(4-methylphenylsulfonyloxy)-2-fluoroethane

→

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

용매

DMF

반응 조건

후처리

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

실험 절차

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.

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