Prallethrin Chemical Properties

Melting point:

25°C

Boiling point:

381.62°C (rough estimate)

Density 

d420 1.03

vapor pressure 

﹤4.3×10^-5 Pa (23.1 °C)

refractive index 

1.4200 (estimate)

Flash point:

139 °C

storage temp. 

2-8°C

solubility 

Chloroform (Sparingly), Ethyl Acetate (Slightly), Methanol (Sparingly)

Water Solubility 

8 mg l^-1 (25 °C)

Stability:

Stable. Incompatible with strong oxidizing agents.

CAS DataBase Reference

23031-36-9(CAS DataBase Reference)

EPA Substance Registry System

Prallethrin (23031-36-9)

Safety Information

Hazard Codes 

T,N

Risk Statements 

22-23-50/53

Safety Statements 

45-60-61

RIDADR 

UN2811 6.1/PG 2

WGK Germany 

3

HS Code 

29162090

Hazardous Substances Data

23031-36-9(Hazardous Substances Data)

Toxicity

mouse,LD50,oral,190mg/kg (190mg/kg),Iyakuhin Kenkyu. Study of Medical Supplies. Vol. 20, Pg. 228, 1989.

Prallethrin Usage And Synthesis

Chemical properties

The original medicine is an oil like liquid. At b.p.>313.5℃ , the relative density is 1.03. It is easy to dissolve in methanol and hexane. The solubility is >50% at normal temperature, The solubility in the water at 25 C is 8.03mg/L, The distribution coefficient is 30800.

Application

The product characteristics of fenvalerate are the same as those of fenpropathrin with strong contact toxicity. The knockdown and killing performance is 4 times higher than that of the right-handed trans pyrethrin, and has a prominent driving effect on cockroaches. It is mainly used for processing mosquito repellent incense, electric mosquito repellent incense, liquid mosquito repellent incense and spray to control household pests such as housefly, mosquito, louse, cockroach etc. The recommended amount of use is as follows: (with effective ingredients) mosquito repellent incense: The electric heat mosquito incense containing 0.05% of the product: Containing 10mg/ tablets of this product to control the temperature of the electric heater center at 125-135℃. Liquid mosquito repellent incense: containing 0.66% of this product, plus proper stabilizer; Sustained-release agent; Aerosols: 0.05 0.2% of this product with appropriate amount of lethal agent, synergist and emulsifier.

Chemical Properties

solid

Uses

Prallethrin is used for the control of insects in domestic and public health situations.

Uses

Prallethrin ia a synthetic pyrethroid; propynyl analog of allethrin. Prallethrin is used as an insecticide.

Definition

ChEBI: Prallethrin is a member of cyclopropanes and a terminal acetylenic compound. It has a role as a pyrethroid ester insecticide and an agrochemical. It is functionally related to a chrysanthemic acid.

Hazard

A poison by ingestion and inhalation. Low toxicity by skin contact.

Pharmacology

Prallethrin is a propynyl analog of allethrin, with 2-methyl-4-oxo-3-(prop-2-ynyl)-cyclopent-2-enyl as the secondary alcohol moiety that has been introduced against public health pests (113–115). The ester of the (S)-alcohol with (1R)-trans,cis-chrysanthemic acid resolved partially is commercialized on the strength of the assessment of insecticidal action of individual stereoisomers (116). Compared with d-allethrin, it is approximately four, six, and five times more effective on Musca domestica (for killing), Blattella germanica (for killing), and Culex pipiens pallens (for knockdown), respectively (43). A lower level of resistance to prallethrin than to phenoxybenzyl pyrethroids was demonstrated in a kdr-resistant housefly strain (116).

Safety Profile

A poison by ingestion and inhalation. Low toxicity by skin contact. When heated to decomposition it emits acrid smoke and irritating vapors.

Metabolic pathway

Prallethrin is stable under normal room temperature storage conditions for up to 36 months. It is labile to alkali at the ester linkage, forming 2 and 3 (Scheme 1). Analogy with the allethrins (from which it differs only in the degree of unsaturation in the side chain - propyne rather than propene) would suggest that the compound is very photolabile.

Degradation

The metabolism of prallethrin was studied following single oral administration and subcutaneous injection of the cis- and trans-isomers to rats at two dose levels and after repeated dosing. The compound was labelled in the alcohol moiety (inferred from the results) (PSD, 1995).
Absorption was rapid with maximum tissue residues being attained 3 hours after the dosing of each isomer. Biphasic clearance of radioactivity then occurred with half-lives of 3 and 14-23 hours (cis-isomer) and 3-5 and 7-35 hours (trans-isomer). Urinary excretion accounted for 13-32% (cis-isomer) and 45-62% (trans-isomer) of the dose with most of the balance in the faeces. Less than 0.1% was exhaled as ¹⁴CO₂ . Residues in tissues were very low (0.3% of the dose at 7 days). Metabolism and disposition were independent of dose and dose route but residues in tissues were somewhat higher for the cis-isomer.
Twenty-one metabolites were identified (taking account of stereochemistry and conjugates). The major pathways of metabolism involved oxidation at a methyl group of the isobutenyl group in the acid moiety (giving 4 and 5), at the C1 and C2 positions of the propynyl group in the alcohol moiety (giving 6 and 9) and dihydroxylation (to 7 and 8). The resulting hydroxy derivatives were conjugated with glucuronic acid and sulfate.
Hydrolysis of prallethrin also occurred to afford the acid 2 (presumed) and the alcohol 3. Hydrolysis of the hydroxylated prallethrins and further oxidation of 3 afforded 10 and 11. Further oxidation of 10 to the cyclic tertiary alcohol (12) was observed.
When bluegill sunfish were exposed to a l4C-labelled (acid and alcohol groups) prallethrin isomer (1Rtrans), more than 50% of the biliary radioactivity recovered from the gall bladder was observed as one ester metabolite. This was identified as the taurine conjugate of carboxylic acid metabolite 5 (Oshima et al., 1992).

Prallethrin(23031-36-9)Related Product Information

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