SYNTHESIS OF CYCLOPENTYL CYANIDE (Cyclopentanecarbonitrile)

CAUTION: Potassium cyanide is very poisonous and should only be handled with great care with the wearing of plastic gloves. All operations should be conducted in an efficient fume cupboard.

• Cyclopentanone (1.7g, 20mmol) and 2,4,6-triisopropylbenzenesulphonyl hydrazide (7.5g, 25 mmol) are stirred together in methanol (30 ml) solution at room temperature for 1 hour. 

• Potassium cyanide (3.9, 60 mmol) is then added and the reaction mixture is heated under reflux for 2 hours. 

• Water (20 ml) is added and the products are extracted with dichloromethane (60 ml) and the extract is washed with a saturated solution of sodium hydrogen carbonate (100 ml) and water (50 ml). 

• The organic layer is dried over magnesium sulphate and evaporated carefully under reduced pressure and the residue distilled to give cyclopentanecarbonitrile, b.p. 101 °C/100mmHg, yield 1.28 g (67%); i.r. 2240cm⁻¹ , ¹³C-n.m.r. (CDCl₃ , TMS) 𝛅 25.0, 27.9, 31.3, and 123.5.