After dissolving 500 mg of {2-(4-hydroxy-3-methoxyphenyl)-2-[4-(5-methyl-[1,2,4]oxadiazol-3-yl)phenylimino]-1-methylsulfanylethylidene}carbamic acid methyl ester in 10 ml of DMF, 314 mg of potassium carbonate and 118 μl of iodoethane were added and the mixture was stirred at room temperature for 6 hours. Water was added to the reaction mixture and extraction was performed with ethyl acetate. After washing the organic layer with water and saturated brine, it was 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 (435 mg, isomeric mixture) as a light yellow solid.
