Cyazofamid is a fungicide that is highly-specific in controlling oomycete plant pathogens such as Phytophthora infestans, the organism which causes late blight in potato.

Its mode of action is thought to involve binding to the Qi center of Coenzyme Q – cytochrome c reductase.

[5] Processes to manufacture cyazofamid were disclosed in patents from Ishihara Sangyo Kaisha, Ltd.[6] An acetophenone derivative was first treated with aqueous glyoxal and hydroxylamine to form an oxime-substituted imidazole ring system.

This intermediate was treated with thionyl chloride and disulfur dichloride to convert the oxime to a cyano group and chlorinate the imidazole in the position next to the phenyl ring.

Finally, treatment with dimethylsulfamoyl chloride gave cyazofamid, with the desired regiochemistry.