反应详情

温度

42.5 °C

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allowing the temperature to reach 50° C. The mixture is stirred 9 hours at an oil bath at 40-45° C., and a sample is withdrawn for NMR, which indicates, that there is still 8% starting material left (signal at 2.8 ppm).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.

1. temperatureis cooled slightly
2. customto reach 50° C
3. customa sample is withdrawn for NMR, which
4. waitleft (signal at 2.8 ppm)
5. additionMore methyl iodide is added (4.6 grams)
6. stirringthe mixture is stirred for another 2½ hour at 40° C.
7. filtrationThe mixture is filtered
8. washthe filter cake is washed with DME
9. customThe filtrate is evaporated to dryness