After dissolving 520 mg of {2-(4-hydroxy-3-methoxyphenyl)-2-[4-(5-methyl-[1,2,4]oxadiazol-3-yl)phenylimino]-1-methylsulfanylethylidene}carbamic acid methyl ester (Example (18d)) in 5 ml of DMF, 262 mg of potassium carbonate and 107 μl of bromoacetonitrile were added and the mixture was stirred at room temperature for 16 hours. Water was added to the reaction mixture and extraction was performed with ethyl acetate. The organic layer was washed with water and saturated brine, and then dried over anhydrous sodium sulfate. The desiccating agent was filtered off and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate-heptane) to give the title compound (514 mg, isomeric mixture) as a light yellow solid.
