Methyl iodide → 2-Methyl-2-(2-pyrrolidinylidene)-acetophenone

Participants

Reaction Steps

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).

Provenance & Evidence