Reaktion #744786

Reaktionsgleichung

3,3-dimethylpiperazin-2-one

potassium carbonate

Methyl iodide

→

title compound

Ausbeute 73.9%

3,3,4-trimethylpiperazin-2-one

Ausbeute 73.9%

Lösungsmittel

1,2-dimethoxyethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturis cooled slightly
2. 2
   Sonstigeto reach 50° C
3. 3
   Sonstigea sample is withdrawn for NMR, which
4. 4
   workup.WAITleft (singal at 2.8 ppm)
5. 5
   workup.ADDITIONMore methyl iodide is added (4.6 grams)
6. 6
   workup.STIRRINGthe mixture is stirred for another 2½ hour at 40° C.
7. 7
   FiltrationThe mixture is filtered
8. 8
   Waschenthe filter cake is washed with DME
9. 9
   SonstigeThe filtrate is evaporated to dryness

Vorschrift

3,3-dimethylpiperazin-2-one (50 grams) is suspended in 1,2-dimethoxyethane (DME) (150 ml) and potassium carbonate (70 grams) is added. Methyl iodide (66.4 grams) is added during half an hour, while the mixture is cooled slightly, allowing the temperature to reach 50° C. The mixture is stirred 9 hours at an oil bath at 40-45° C., and a sample is withdrawn for NMR, which indicates, that there is still 8% starting material left (singal at 2.8 ppm). More methyl iodide is added (4.6 grams), and the mixture is stirred for another 2½ hour at 40° C., and a new NMR sample shows full conversion. The mixture is filtered, and the filter cake is washed with DME. The filtrate is evaporated to dryness giving 41 grams of the title compound. NMR complies with the structure.

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