A solution of
57 g. (0.88 mole) of potassium cyanide in 570 ml. of water is placed in a
1-l. three-necked flask equipped with a
stirrer and a
reflux condenser.
Fifty-eight grams (0.15 mole) of N,N-dimethylaminomethylferrocene methiodide2 is added and the mixture is heated to boiling with good stirring. As the mixture is brought to boiling, the solid goes into solution. Within a few minutes of the onset of boiling, evolution of
trimethylamine begins and a steam-volatile oil starts to separate from the solution. The reaction mixture is boiled vigorously with stirring for 2 hours and then is allowed to cool to room temperature. During the cooling the oil that has separated solidifies.
The solid is separated by filtration and the filtrate is extracted with three
150-ml. portions of ether.
(Caution! Gloves should be worn when handling this solution because of the large amount of cyanide it contains.) The solid is dissolved in
ether and this solution is combined with the extracts. The combined ethereal solutions are washed with water and dried over
5 g. of sodium sulfate. Removal of the solvent by distillation leaves crude
ferrocenylacetonitrile as a solid or as an oil that crystallizes on being scratched. The nitrile is dissolved in about
200 ml. of boiling technical grade hexane. The hot solution is decanted from a small amount of insoluble black tar and is cooled to room temperature.
Ferrocenylacetonitrile is deposited as bright yellow crystals, m.p.
79–82° (Note
1). The yield of the nitrile is
24–26 g. (
71–77%) (Note
2).