A solution of 10 mg (0.09 mmol) of acetic acid in dichloromethane is treated with 10 mg (0.09 mmol) of HOBt and 20 mg (0.21 mmol) of 4-methylmorpholine. The mixture is cooled to −20° C. and treated with 20 mg (0.09 mmol) of EDC. It is stirred for 30 min. Subsequently, 30 mg (0.07 mmol) of 4-[5,7-dimethyl-4-(3,4,5-tri-methoxyphenoxy)imidazo[5,1-f][1,2,4]triazin-2-yl]aniline from example 1 are added thereto at −20° C., and the mixture is stirred for 5 h at 20° C. The solution is then washed with aqueous 1 N potassium hydrogensulfate solution and saturated aqueous sodium hydrogencarbonate solution. The organic phase is dried and concentrated under reduced pressure. The residue is purified by flash chromatography (eluent:dichloromethane/methanol 100:1-80:1-60:1).
