Chemical Properties
yellow crystalline powder
Definition
ChEBI: A maleimide that is substituted at positions 3 and 4 by chlorines and on the nitrogen by a p-fluorophenyl group. Previously used as a fungicide (now obsolete).
Uses
Fluoroimide is used to control Monilinia mali and Mycosphaerella
pomi in apples, Diaporthe citri and Elsinoe fawcetti in citrus, Corticium spp.
in rubber trees, Botryfis cinerea and Peronospora destructor in onions,
Colletotrichum theae-sinensis and Exobasidium vexans in tea, Phytophthora
infestans in potatoes at 2-5 kg a.i. ha-1 and Cercospora kaki and
Mycosphaerella mwae in persimmons at 0.5-2 kg ha-1.
Production Methods
Commercial production information for fluoroimide is not described in open literature. However, based on its structure and chemistry production would follow the standard maleimide route, beginning with preparation of a dichloromaleic anhydride or dichloromaleic acid intermediate, which is then converted to the corresponding acid chloride under controlled chlorination conditions. This activated intermediate would be condensed with p fluoroaniline to form the N aryl maleamic acid, followed by cyclodehydration to yield the imide ring.
Mechanism of action
Protective and curative activity, inhibits spore germination
Metabolic pathway
Fluoroimide is a relatively volatile solid with a high melting point.
It degrades to a range of products in soils and plants. The main pathways
are hydrolysis of the amide bond causing scission of the maleimide
ring and stepwise reduction involving dechlorination of the maleimide
ring. Little transformation of the parent fungicide occurred on plants.
Degradation
Hydrolysis of fluoroimide is base catalysed. The DT50 values for the
hydrolysis are 52.9,7.5 and 1.4 minutes at pH 3,7 and 8, respectively. The
fungicide is stable to sunlight (PM).
