Water → alpha-Cypermethrin 1-Epimeric Mixture

Participants

Reaction Steps

To a stirred solution of sodium cyanide (0.74 g, 0.015 mold) in a 1:1 by volume mixture of water and acetonitrile (20 ml) at room temperature was added all at once 3-phenoxybenzaldehyde (1.98 g, 0.01 mole) in the same solvent system (5 ml) followed by a dropwise addition over 10 minutes of cis-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarbonyl chloride (2.73 g, 0.012 mole). Stirring was continued at room temperature for 2 hours, after which the mixture was extracted thrice with methylene chloride (30 ml each). The combined organic layers were washed once with aqueous 2 N NaOH (25 ml), then thrice with water (25 ml each) to a final wash pH of about 6, dried over Na2SO4, and concentrated to give α-cyano-3-phenoxybenzyl cis-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate (3.76 g, 90% yield).

Provenance & Evidence