0.59 g of 1-(6-(1,2,3,6-tetrahydropyridin-4-yl)quinolin-4-yl)-3-(6-(trifluoromethyl)pyridin-2-yl)urea (0.427 mmol) were dissolved in a mixture of 143 ml of dioxane and 10 ml of ethanol. After addition of 0.152 g of Pd/C (1.427 mmol) and 0.082 ml of acetic acid (1.427 mmol), hydrogenation was performed for 7 h at 60° C. and over night at room temperature, which led to complete double bond hydrogenation according to HPLC/MSD analysis. The catalyst was filtered off, the solvent removed under reduced pressure and the residue extracted three times with ethyl acetate after adding water and a small amount of NaOH (pH 9). The combined organic phases were washed with a small amount of brine, dried over sodium sulfate and the solvent was removed under reduced pressure. 593 mg of the desired product were obtained as light yellow powder (yield: 64%).
