反应详情

25 g of 1-(1-carbobenzoxy-4-piperidyl)-imidazolidin-2-one are added in portions to a mixture, which has been warmed to 80° C., of 2.4 g of sodium hydride in 100 ml of absolute dimethylformamide, with stirring. The mixture is stirred for a further 2 hours at 80° C. and 18.2 g of n-butyl iodide are then allowed to run in slowly dropwise (highly exothermic reaction). After stirring for a further 2 hours at 80° C., the reaction mixture is evaporated under reduced pressure and the residue is freed from dimethylformamide which is still adhering, by treatment with toluene. The reaction product is dissolved in 250 ml of ethyl acetate and the solution is washed twice with, in each case, 50 ml of water, dried over sodium sulphate and evaporated to dryness. The residue is chromatographed on 1.5 kg of silica gel using a mixture of chloroform/methyl alcohol (95:5) as the eluant mixture. In this way, 3-n-butyl-1-(1-carbobenzoxy-4-piperidyl)-imidazolidin-2-one is obtained in the form of a colourless oil.

1. stirringThe mixture is stirred for a further 2 hours at 80° C.
2. customhighly exothermic reaction)
3. stirringAfter stirring for a further 2 hours at 80° C.
4. customthe reaction mixture is evaporated under reduced pressure
5. dissolutionThe reaction product is dissolved in 250 ml of ethyl acetate
6. washthe solution is washed twice with, in each case, 50 ml of water
7. dry with materialdried over sodium sulphate
8. customevaporated to dryness
9. customThe residue is chromatographed on 1.5 kg of silica gel using
10. additiona mixture of chloroform/methyl alcohol (95:5) as the eluant mixture