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 A mode of action (MoA) describes a functional or anatomical change, resulting from the exposure of a living organism to a substance. In comparison, a mechanism of action (MOA) describes such changes at the molecular level. A mode of action is impor ...

is thought to involve binding to the Q_i center of Coenzyme Q – cytochrome c reductase. Cyazofamid is most often sold under the brand name Ranman.

Synthesis

Processes to manufacture cyazofamid were disclosed in patents from Ishihara Sangyo Kaisha, Ltd. 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 Disulfur dichloride is the inorganic compound of sulfur and chlorine with the Chemical formula, formula S2Cl2. Some alternative names for this compound are ''sulfur monochloride'' (the name implied by its empirical formula, SCl), ''disulphur dich ...

to convert the oxime to a

cyano group Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms. In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of a ...

and chlorinate the imidazole in the position next to the phenyl ring. Finally, treatment with dimethylsulfamoyl chloride gave cyazofamid, with the desired

regiochemistry In chemistry, regioselectivity is the preference of chemical bonding or breaking in one direction over all other possible directions. It can often apply to which of many possible positions a reagent will affect, such as which proton a strong base ...

. This placed the sulfamoyl group on the nitrogen adjacent to the phenyl ring rather than the chlorine atom. The structure of the fungicide has been confirmed by X-ray crystallography. : Cyazofamid synthesis

References

External links

* * {{chemistry-stub Fungicides Sulfonamides Imidazole antifungals Nitriles Chloroarenes

Synthesis

References

Further reading

External links