Аллетролон

Description

Alletrolone (4-hydroxy-3-methyl-2-(2-propenyl)-2-cyclopenten-1-one) is a cyclopentenone with hydroxyl, methyl and allyl groups, a key alcohol component of pyrethroid insecticides of the allethrin series. An intermediate product of pesticide chemistry: esterification of alletrolone with chrysanthemum acid produces allethrin itself.

Basic Attributes

• CAS No.: 29605-88-7
• Chemical formula: C9H12O2
• Molecular weight: 152.19
• Exact weight: 152.19
• EU number: 249-724-0
• NSC Number: 42192
• PSA specifications: 37.3
• XLogP3: 1.21270

Physico-chemical characteristics

• Density: 1.082 g/cm3
• Boiling point: 100-103 °C at 0.15 mm Hg. Art.
• Flash point: 115.2 °C
• Refractive index: 1.533
• Steam pressure: 0.001 mmHg Art. at 25 °C

Synonyms

2-Cyclopenten-1-one, 4-hydroxy-3-methyl-2-(2-propen-1-yl)-; 2-Cyclopenten-1-one, 2-allyl-4-hydroxy-3-methyl-, (±)-; 2-Cyclopenten-1-one, 4-hydroxy-3-methyl-2-(2-propenyl)-, (±)-.

Scope of application

An intermediate product for the synthesis of pyrethroid insecticides of the allethrin group: alletrolone is esterified with chrysanthemum (2,2-dimethyl-3-(2-methylpropenyl)cyclopropanecarboxylic) acid, obtaining an ester - the active substance of allethrin and its stereoisomeric forms (bioalletrin, esdepalletrin). Commercial alletrolone is used by manufacturers of plant protection products and household insecticides as raw materials for their own production of pyrethroids, and not as an independent active agent. The cyclopentenone ring with a hydroxyl in the allylic position and a methyl group at the double bond sets the stereochemistry of the future ester and determines the insecticidal activity of the final product - type I allethrin (without alpha-cyano substituent).

Chemical role in the synthesis of pyrethroids

Alletrolone is produced industrially from cyclopentane raw materials according to the classical Hageman condensation scheme with subsequent addition of allyl and methyl groups; the commercial substance is supplied in the form of a racemate (±) for subsequent esterification; if necessary, the optically active forms are separated at the stage of obtaining bioallethrin.

Safety Information

• Precautions: P273, P391, P501
• Hazard Statement: H400 - Very toxic to aquatic life

GHS classification according to H400 was confirmed for 100% of the sample - data aggregated for 2 companies from 1 notification to the ECHA C&L Register. For a separate, broader set of data (38 companies from 1 notification), H302 is added - harmful if swallowed (100% of the sample), with precautions P261, P264, P270, P272, P280, P301+P312, P302+P352, P321, P330, P333+P313, P363, P501.

Storage and transportation conditions

Store in a tightly closed container, do not allow it to enter wastewater or water bodies - the substance is classified as very toxic to aquatic organisms. Wear gloves and safety glasses to avoid ingestion.

Additionally

By itself, the cyclopentenone ring of alletrolone is relatively heat stable and can withstand the temperatures used in chrysanthemum acid esterification without decomposition; the vapor pressure is extremely low (0.001 mmHg at 25 °C), so the volatility of the substance at room temperature is negligible.