A mixture of 0.678 g (3 mmol) of 2-bromo-5-(trifluoromethyl)pyridine, 0.901 g (4.5 mmol) of tert-butyl 4-aminopiperidine-1-carboxylate and 0.829 g (6 mmol) of potassium carbonate in 5 ml of dimethyl sulphoxide is heated at 100° C. for 20 hours. The mixture is cooled to ambient temperature and then 50 ml of ethyl acetate and 15 ml of water are added. The organic phase is separated by settling and washed twice with 15 ml of water and then with 15 ml of a saturated aqueous sodium chloride solution. It is dried over sodium sulphate and evaporated under vacuum. The product is purified by chromatography on silica gel, elution being carried out with a 20:80 and then 30:70 mixture of ethyl acetate and cyclohexane in order to obtain 0.864 g (2.5 mmol) of product in the form of a white solid.
