Tetrahydrofuran → Cypermethrin

Participants

Reaction Steps

Sodium cyanide (0.765 g, 15.6 mmole), along with 20 ml of 2:1 tetrahydrofuran:water by volume, was charged to a reaction flask, and the resultant solution was stirred while the temperature was raised to 40°. 3-Phenoxybenzaldehyde (2.06 g, 10 mmole) was added in 5 ml of the tetrahydrofuran/water mixture (25 ml total). 3-(2,2-Dichloroethenyl)-2,2-dimethylcyclopropanecarbonyl chloride (2.84 g, 12.5 mmole) was then added to the flask dropwise over a 10 minute period. The temperature of the reaction mixture was maintained between 40° and 40° during the acyl chloride addition. The reaction mixture was then stirred at 40° for an additional 2 hours, after which it was extracted three times with 15 ml portions of n-heptane. The combined organic phases were washed once with water (15 ml), once with a 2 N aqueous sodium hydroxide solution (15 ml), three more times with water (15 ml) portions), dried over magnesium sulfate, filtered, and concentrated under reduced pressure. A quantitative yield of α-cyano-3-phenoxybenzyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate remained as the residue.

Provenance & Evidence