This invention belongs to the field of
pesticide technical preparation technology, specifically providing a purification method for difenoconazole. The first step involves dissolving crude difenoconazole containing isomers in a first
organic solvent and heating to a clear solution, then adding a
copper chloride methanol solution to react and generate difenoconazole
copper salt. The second step involves reducing the difenoconazole
copper salt obtained in the first step in a second
organic solvent using liquid alkali, then separating the difenoconazole oil and
filter cake. The separated
filter cake is adjusted with dilute
hydrochloric acid to obtain
copper chloride. The third step involves the preparation of pure difenoconazole: dissolving the difenoconazole oil obtained in the second step in a polar
solvent, then adding n-
hexane, n-
heptane, or methyl tert-butyl
ether dropwise, and recrystallizing to obtain pure difenoconazole
solid. Compared with existing technologies, this method overcomes the defects of existing technologies such as strong
acid corrosion, difficulty in recovering
metal salts, and incomplete
impurity removal, and achieves higher purity.