合成路线1

2,6-Dichlorobenzenethiol (I) is oxidized to the sulfonyl chloride (II) employing N-chlorosuccinimide. Subsequent treatment of acid chloride (II) with ammonia in cold pyridine provides sulfonamide (III). Reaction of (III) with HNO3 in the presence of concentrated H2SO4 leads to the nitro derivative (IV). Then, displacement of one chloride group of (IV) with potassium acetate in the presence of crown ether gives rise to the acetate ester (V), which is further hydrolyzed to phenol (VI) under acidic conditions. Nitro group reduction in (VI) with H2 and Pd/C affords aniline (VII). Finally, coupling of (VII) with 2,3-dichlorophenyl isocyanate (VIII) produces the title diaryl urea.