Трансхризантемовая кислота

Description

Trans-chrysanthemum acid is a 2,2-dimethyl-3-(2-methyl-1-propen-1-yl)cyclopropanecarboxylic acid in the trans series, racemate of the (1R,3R)-rel configuration. The acid component of natural pyrethrins and a significant part of synthetic pyrethroids. In natural insecticides of Dalmatian chamomile, the alcohol part of the ester is represented by pyretrolone, cierolon or jasmolone, and the acid part is chrysanthemum or pyrethric acid. Intermediate product of pesticide synthesis.

Basic Attributes

• CAS No.: 705-16-8
• Chemical formula: C10H16O2
• Molecular Weight: 168.233
• Exact weight: 168.23
• EU number: 225-067-5
• UNII: 75957WZ15Y
• PSA specifications: 37.3
• XLogP3: 2.81

Physico-chemical characteristics

• Density: 1.1 ± 0.1 g/cm3
• Melting point: 17–21 °C
• Boiling point: 85–90 °C at 0.3 Torr pressure
• Flash point: 119.0 ± 18.9 °C
• Refractive index: 1.547

Role in pyrethroid synthesis

The acid is esterified with various alcohols, and the resulting esters make up a large group of insecticides: allethrin, tetramethrin, phenothrin, resmethrin, bioresmethrin, prallethrin. The activity of the ester is highly dependent on the stereochemistry of the acid moiety. Esters based on the trans form of the acid inhibit insects much more effectively than esters of the cis form, and esters of the (+) isomer are much more active than esters of the corresponding (-) isomer. That is why isomers are separated in production and methods of racemization of inactive forms are used to return them to the cycle.

Scope of application

• intermediate in the production of pyrethroid insecticides
• raw material for the production of acid chloride and subsequent esterification with an alcohol component
• analytical standard for monitoring the composition of pyrethroids and their hydrolysis products
• model compound in work on the biosynthesis of pyrethrins

Safety Information

• Hazard Statements: H302 - Harmful if swallowed
• Precautions: P261, P264, P270, P271, P272, P280, P285, P301+P312, P302+P352, P304+P340, P304+P341, P305+P351+P338, P312, P321, P330, P332+P313, P333+P313, P337+P313, P342+P311, P362, P363, P403+P233, P405, P501

Storage and handling

Melting points of 17–21 °C fall within the range of normal storage conditions: the product changes from solid to liquid with only a slight change in temperature, which is taken into account during sampling and dosing. The isolated double bond of the isopropenyl moiety is sensitive to oxidation, so the container is kept tightly closed, away from oxidizing agents and heat sources. Store in a cool, ventilated area, away from light. Work with gloves and safety glasses, when heated - under a hood.