Hydrochloric Acid → 2,2-Dichlorovinyl 2,4-dichloro-5-fluorophenyl ketone

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Reaction Steps

136.5 g (0.6 mole) of 2,4-dichloro-5-fluorobenzoyl chloride and 97 g (1 mole) of 1,1-dichloroethylene are successively added dropwise to a suspension of 84 g of anhydrous aluminum chloride in 300 ml of methylene chloride, while cooling with ice and stirring, during which the temperature should not exceed 30° C. The mixture is stirred at room temperature for 3 hours and poured onto a mixture of about 600 g of ice and 60 ml of concentrated hydrochloric acid, the organic phase is separated off and the aqueous phase is subsequently extracted three times with 100 ml of methylene chloride. The methylene chloride solution is washed with 100 ml of water and dried with sodium sulphate and the solvent is distilled off in vacuo. The residue (218.8 g) is heated at 130°-140° C. with 0.34 g of triphenylphosphine until the initially vigorous evolution of HCl has ended (about 3/4 hour). Distillation under a fine vacuum gives 167.1 g (96.4%) of 2,2-dichlorovinyl 2,4-dichloro-5-fluorophenyl ketone of boiling point 121°-123° C./0.13 mbar, melting point 64°-65° C.

Provenance & Evidence