반응 #559690

반응 방정식

1-(3-nitro-phenyl)-piperazin-2-one

acetaldehyde

acetic acid

Sodium cyanoborohydride

→

4-Ethyl-1-(3-nitro-phenyl)-piperazin-2-one

용매

methanol

반응 조건

후처리

1. 1
   기타The mixture was evaporated
2. 2
   workup.ADDITIONcold water was slowly added to the residue
3. 3
   workup.STIRRINGThe mixture was stirred for 15 minutes
4. 4
   추출extracted with dichloromethane (3×20 mL)
5. 5
   건조The combined organic layers were dried over magnesium sulfate
6. 6
   여과filtered
7. 7
   기타evaporated
8. 8
   기타The residue was purified via chromatography
9. 9
   기타purification apparatus (silica gel column 40 g and 0%→5% methanol:dichloromethane)

실험 절차

205 b) To a solution of 1-(3-nitro-phenyl)-piperazin-2-one (0.629 g, 2.84 mmol), acetaldehyde (0.20 mL, 3.6 mmol) and acetic acid (0.50 mL, 8.8 mmol) in methanol (10 mL) at room temperature was added solid Sodium cyanoborohydride (0.27 g, 4.3 mmol) in small portions. The mixture was stirred for 18 hours at room temperature. The mixture was evaporated and cold water was slowly added to the residue. The mixture was stirred for 15 minutes and then extracted with dichloromethane (3×20 mL). The combined organic layers were dried over magnesium sulfate, filtered and evaporated. The residue was purified via chromatography using an ISCO automated purification apparatus (silica gel column 40 g and 0%→5% methanol:dichloromethane). 4-Ethyl-1-(3-nitro-phenyl)-piperazin-2-one was isolated as a yellow-orange viscous oil (0.497 g, 70%). 1H NMR (400 MHz, CDCl3, δ, ppm): 8.21 (s, 1H), 8.13 (d, J=8.1 Hz, 1H), 7.74 (d, J=7.9 Hz, 1H), 7.57 (t, J=7.8 Hz, 1H), 3.81-3.76 (m, 2H), 3.37-3.33 (m, 2H), 2.89-2.84 (m, 2H), 2.60-2.53 (m, 2H), 1.20-1.14 (m, 3H).

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