反应详情

17.0 g of α-(2-pyrrolidinylidene-acetophenone and 11.3 g of potassium-tert.-butoxide are dissolved in a mixture of 8 ml of dimethylformamide and 170 ml of benzene. A solution of 25 g of methyl iodide in 25 ml of benzene is added dropwise within 30 minutes. The reaction mixture heats up to 38°. It is stirred for 2 hours at room temperature; to the reaction mixture is then added a further 2.5 g of potassium tert.-butoxide and it is subsequently stirred for 15 hours at room temperature. The cloudy reaction mixture is filtered clear with the aid of diatomaceous earth; it is concentrated by evaporation and the evaporation residue is chromatographed on a silica-gel column with an ethyl acetate/hexane mixture (volume ratio 1:1). There is obtained 2-methyl-2-(2-pyrrolidinylidene)-acetophenone, m.p. 91°-92° (from cyclohexane).

1. customheats up to 38°
2. stirringis subsequently stirred for 15 hours at room temperature
3. customThe cloudy reaction mixture
4. filtrationis filtered clear with the aid of diatomaceous earth
5. concentrationit is concentrated by evaporation
6. customthe evaporation residue is chromatographed on a silica-gel column with an ethyl acetate/hexane mixture (volume ratio 1:1)