Benzene → Phenyl phosphorus dichloride

Participants

Reaction Steps

8800 g (64 mols) phosphorus(III)chloride, 780 g (10 mols) benzene and 1361 g (10 mols) anhydrous aluminum chloride of 98% strength were boiled for 5 hours under reflux in a reactor provided with a stirrer and reflux condenser. Next, 1535 g (10 mols) phosphorus oxychloride was added dropwise within 30 minutes. After a post-reaction period of 30 minutes, the whole was cooled to 25° C., the formed aluminum chloride/phosphorus oxychloride-complex was filtered off and washed with phosphorus(III)chloride. 3128 g crystalline matter moist with PCl3 was obtained (theoretically: 1535 g POCl3 +1361 g AlCl3 =2896 g). Phosphorus(III)chloride in excess and unreacted benzene were expelled from the filtrate under atmospheric pressure and the residue was distilled under vacuum. 1561 g phenyldichlorophosphane (bp: 95° C. at 25 millibars) was obtained. Yield: 0.87 mol C6H5PCl2 per mol AlCl3.

Provenance & Evidence