2-ETHYL CAPRONITRILE

Preparation

In a 1-L round-bottomed flask, fitted with an efficient reflux condenser, were placed 2-ethylhexaneamide 1455 (286 g, 2 mol), dry benzene (300 mL), and thionyl chloride (357 g, 218 mL, 3 mol). The flask was placed in a water bath, which was quickly heated to 75–80 C° and maintained at that temperature for 4.5 h. The reaction mixture was then transferred to a 1.5-L beaker and cooled in an ice bath. A mixture of crushed ice (100 g) and water (100 mL) was added to decompose the excess thionyl chloride. Cold 50% aq. potassium hydroxide solution was then added in small portions with stirring until the mixture was alkaline to litmus. The basified mixture was then transferred to a separatory funnel, and the layers were separated. The aqueous portion was extracted with benzene (100 mL). The benzene solutions were combined and washed with 1% sodium carbonate solution (150 mL) and water (2 × 150 mL). The mixture was distilled from a modified Claisen flask, the bulk of the solvent being removed at atmospheric pressure. The yield of nitrile 1456 was 215–236 g (86–94%); bp 118–120 C°/100 mmHg.