Pyridine → (4-Fluorophenyl)phosphonous dichloride

Participants

Reaction Conditions

Reaction Steps

A mixture of 3.4 mol of PCl3 and 1.2 mol of AlCl3 (98% pure) was placed under an argon atmosphere in a 1 l flask which was provided with a thermostated jacket, mechanical stirring, thermometer and reflux condenser at 73° C. 0.8 mol of fluorobenzene was subsequently added over a period of 30 minutes, with a gentle stream of argon being passed through the reaction flask. The reaction mixture was stirred for 3 hours, cooled to 60° C. and 1.25 mol of pyridine were slowly added over a period of 45 minutes. The reaction was exothermic and mist was formed. The mixture was subsequently stirred for another 30 minutes at 60° C. A nonuniform solid in the form of large lumps precipitated, and this could not be separated off via a suction filter but only by filtration. The filtration residue was washed with petroleum ether. The filtrate and the washings were combined and distilled, giving 73.3 g of p-fluorophenyldichlorophosphine in a yield of 47% of theory.

Provenance & Evidence