tert-Butyl 4-[[[(E)-[(1,3-Dimethyl-5-phenoxy-1H-pyrazol-4-yl)methylene]amino]oxy]methyl]benzoate

Description

Fenpyroximate is a pyrazolium insecticide used to control important phytophagous mites in fruit and other crops. It has a low aqueous solubility and is not considered a volatile substance. Whilst it is not normally persistent in water bodies, it can be persistent in soils depending upon local conditions. Based on its physico-chemical properties fenpyroximate is not expected to leach to groundwater. Toxicity to biodiversity tends to be considered high to moderate. It has moderate oral toxicity to humans and there are concerns that it may be a developmental/reproduction toxin.

Uses

Acaricide.

Production Methods

Fenproxymate is commercially produced through a multi-step synthesis involving pyrazole-based intermediates. A key step includes the preparation of pyrazole-1,3-dimethyl-5-phenoxy-4-carboxaldehyde oxime, which serves as a crucial building block. This intermediate is then reacted with methyl isocyanate or similar carbamoylating agents to form the final carbamate structure of fenproxymate. The reactions are typically carried out in organic solvents under controlled temperature and pH conditions to ensure high yield and purity.

Definition

ChEBI: Fenpyroximate is a pyrazole acaricide and a tert-butyl ester. It has a role as a mitochondrial NADH:ubiquinone reductase inhibitor. It derives from a hydride of a 1H-pyrazole.

Agricultural Uses

Acaricide, Miticide, Insecticide: Used to control spider mites in greenhouses.

Trade name

AKARI®; HOE® 555-02A; NNI®-850; SEQUEL®

Mechanism of action

Contact action. Mitochondrial complex I electron transport inhibitor.

Metabolic pathway

When fenpyroximate is administered orally to rats, radiocarbons from 14C-fenpyroximate are rapidly and almost completely excreted in the urine and feces within 72 h, and fenyproximate seems to be metabolized via oxidation of the tert-butyl group and methyl group at the 3-position in the pyrazole ring, p- hydroxylation in the phenoxy moiety, N-demethylation, hydrolysis of the tert-butyl ester, cleavage of the oxime ether bond, and/or E/Z isomerization. In soils, 12 degradation products are identified, and in sterilized soils the degradation of fenpyroximate and CO2, evolution are negligible. Fenpyroximate degrades through hydrolysis of tert-butyl ester, isomerization or cleavage of the oxime ether, N-demethylation, oxidation of the methyl group at the 3-position on the pyrazole ring, and hydroxylation of the phenoxy ring, and is finally mineralized to CO2 and/or bound to soil organic matter.

Pesticide Type

Acaricide; Insecticide