Preparation method of ponazuril

The invention relates to a preparation method of ponazuril which is an anti-coccidiosis drug. The method includes syntheses of 3-methyl-4-(4-phenoxy trifluoromethyl sulfide)-nitrobenzene, 3-methyl-4-(4-phenoxy trifluoromethyl sulfide)-aniline, 3-methyl-4-(4-phenoxy trifluoromethyl sulfide)-phenyl isocyanate, 1-[3-methyl-4-(4-phenoxy trifluoromethyl sulfide)-m-methylphenyl]-1,3,5-triazine-2,4,6-trione and ponazuril. Dangerous articles such as raney nickel, methyl isocyanate, chloroformylisocyanate, phosgene, triphosgene and hydrazine hydrate are not used during the reaction processes, and the operation is safe and reliable; raw materials are easy to obtain, the production cost and pollution are low, and the production process is environment-friendly; and the preparation method is simple, special equipment is not needed, a total yield of ponazuril product can reach above 60%, and large-scaleindustrial production is facilitated.