Water → 2-Fluorobenzoyl chloride

Participants

Reaction Steps

To a stirred mixture of 79.5 g of 2-fluorobenzoic acid, 2-(4-fluorophenyl)hydrazide in 350 ml of diethyl ether was added, portionwise, 80.0 g of phosphorous pentachloride. Upon completion of the addition, the reaction mixture was refluxed for 1 hr and then stirred at ambient temperature for 16 hrs. In the following order, a solution of 81.3 g of phenol in 80 ml of diethyl ether, 385 ml of methanol, and sufficient water to reach the solution cloud point, were added, dropwise, to the reaction mixture. Upon standing the reaction mixture separated into two layers. The bottom layer was collected, washed with water, and extracted with diethyl ether. The extract was washed with water, dried over anhydrous magnesium sulfate and concentrated to an oil. The oil was purified by flash chromatography on silica gel using 5% ethyl acetate-hexane as the eluent. Evaporation of the appropriate fractions gave 61.5 g of α-chloro-2-fluorobenzaldehyde, (4-fluorophenyl)hydrazone as an oil. Distillation gave the analytical sample bp 144°-155°.

Provenance & Evidence