Conversion of fungicide cyprodinil to salts with organic acids: preparation, characterization, advantages.

Background: As an effective strategy to improve the basic properties of drugs, salt formation was less used in the field of pesticides than the medicine field. It is worth trying to improve the inherent shortcomings of cyprodinil (high K values; polymorphism) in this way to enhance its practicality.

Results: Eight cyprodinil salts (CYP-Salts) were prepared. The properties of CYP-Salts, including solubility in various solvents, polymorphic behavior, soil absorption, photolysis in aquatic water, in vitro fungicidal activity and curative activity, were assessed. It was observed that compared with those of cyprodinil, CYP-Salts had lower soil adsorption, while also having lower log K values and could be more easily photodegraded in water. That is, CYP-Salts have lower impacts on water bodies and aquatic organisms than cyprodinil. Three CYP-Salts showed higher in vitro antifungal activities and curative activity. CYP-Salts have enhanced practicality, as they could avoid possible agglomeration caused by recrystallization.

Conclusion: Salt forming enhanced the properties of Cyprodinil in many aspects. CYP-Salts may potentially become a better substitute for cyprodinil. This study offers a more economical and effective strategy to prepare better alternatives to existing fungicides. © 2022 Society of Chemical Industry.