Pyrimethanil

Chemical properties

Pyrimethanil is a white to light yellow crystalline powder which is sparingly soluble in water but soluble in most organic solvents. Commercial product is available as a brown emulsifiable concentrate.

The Uses of Pyrimethanil

Pyrimethanil is a broad spectrum anilino-pyrimidine foliar fungicide. Pyrimethanil functions by inhibiting the biosynthesis of methionine in Botrytis cinerea.

The Uses of Pyrimethanil

Pyrimethanil provides both protective and curative control of fungal diseases in pome fruits (leaf scab caused by Venturiu inaequalis), vines, fruits, vegetables and ornamentals (grey mould)

What are the applications of Application

Pyrimethanil is a broad spectrum anilino-pyrimidine foliar fungicide

Definition

ChEBI: Pyrimethanil is a member of the class of aminopyrimidines that is N-phenylpyrimidin-2-amine carrying two additional methyl substituents at positions 4 and 6. A fungicide used to control grey mould on fruit, vegetables and ornamentals as well as leaf scab on pome fruit. Also commonly employed to control Botrytis cinerea throughout the winemaking process in grapes, must, fermenting must and wine. It has a role as an aryl hydrocarbon receptor agonist, an environmental contaminant, a xenobiotic and an antifungal agrochemical. It is an aminopyrimidine, a secondary amino compound and an anilinopyrimidine fungicide.

Preparation

Pyrimethanil is produced by reaction of 2-bromo-4,6-dimethylpyrimidine with aniline.

Synthesis Reference(s)

Chemical and Pharmaceutical Bulletin, 30, p. 1942, 1982 DOI: 10.1248/cpb.30.1942

General Description

Pyrimethanil is an anilino-pyrimidine, broad spectrum fungicide primarily used for the control of gray mould and leaf scab on fruits, vegetables and ornamentals. Its mode of action involves inhibition of the secretion of hydrolytic enzymes by the fungi during the infection process, thus stopping the further development of the disease.

Agricultural Uses

Fungicide: Used on grapes, strawberries, tomatoes, onions, beans, cucumbers, eggplant, and ornamental.

Trade name

SCALA®; SN 100309®

Potential Exposure

A pyrimidine fungicide used on grapes, strawberries, tomatoes, onions, beans, cucumbers, eggplant, and ornamental plants.

Metabolic pathway

Limited data are available in the open literature. Information presented in this summary is abstracted from the data evaluation published by the Pesticide Safety Directorate (PSD, 1995). Hydroxylation at the methyl, phenyl or pyrimidine moiety is the primary metabolic pathway of pyrimethanil in soil, plants and animals. Cleavage of the aniho-pyrimidine linkage was observed as a minor metabolic reaction. The formation of nitro- analogues of pyrimethanil is a novel nitration reaction observed in the soil metabolism study (Scheme 1).

Shipping

UN3082 Environmentally hazardous substances, liquid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous material, Technical Name Required. UN3077 Environmentally hazardous substances, solid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous material, Technical Name Required.

Degradation

Pyrimethanil (1) is stable to hydrolytic degradation in the environmentally relevant pH range (5-9) at 22-50 °C.
Pyrimethanil degraded rapidly at pH 4 and 30 °C (DT₅₀ 1 day) when the sterile buffered solution was exposed to mercury arc lamp (200-500 nm). The DT₅₀ of pyrimethanil in pH 7 solution under the same photolysis test conditions was ca.77 days. There is no information on the chemical nature of pyrimethanil aqueous photolysis products.

Incompatibilities

Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explo- sions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides.

Waste Disposal

Containers must be disposed of properly by following package label directions or by contacting your local or federal environmental control agency, or by contacting your regional EPA office. If this material cannot be disposed of according to label instruc- tions, it may be dissolved or mixed with a combustible sol- vent and burned in a chemical incinerator equipped with an afterburner and scrubber. In accordance with 40CFR165, follow recommendations for the disposal of pesticides and pesticide containers.