A solution of 4-methoxy-3-(4-methylpiperazin-1-yl)aniline dihydrochloride (2.65 g; 9 mmol), triethylamine (4.5 ml; 31.5 mmol) and N,N′-carbonyldiimidazole (1.6 g; 10 mmol) in 125 ml of acetonitrile is stirred at room temperature for 3 hours. A suspension of 2.0 g (9 mmol) of 5-fluoro-3-piperidin-4-yl-1H-indole and 1.3 ml (9 mmol) of triethylamine in 125 ml of acetonitrile is added to the mixture and it is stirred at room temperature for a further 12 hours. After customary working up, the residue is dissolved in acetone and the hydrochloride is precipitated using 1N HCl. By recrystallization from ethanol/diethyl ether, 4-(5-fluoro-1H-indole-3-yl)piperidine-1-carboxylic acid [4-methoxy-3-(4-methylpiperazin-1-yl)phenyl]amide hydrochloride is obtained
