Phosphorus sulfobromide

Phosphorus(V) oxybromide, 2 151 Phosphorus(V) sulfobromide, 2 153 Phdsphorus(V) sulfobromodifluo-ride, formation of, from phosphorus (V) sulfobromide, 2 154 Phosphorus (V) sulfochloride, 4 71 from phosphorus (III) chloride, aluminum chloride, and sulfur, 4 71... 

Of the various methods of preparing phosphorus (V) sulfobromide, experience has shown that the simplest is that of Michaelis. In consists of digesting phosphorus(V) sulfide and phosphorus (V) bromide until the reaction is complete, followed by suitable purification. 

Using an all-glass condenser and connections (standard-taper conical-joint connections preferred) the phosphorus (V) sulfobromide is distilled at about 25 mm. pressure, and the crude product boiling between 120 to 130° is collected. The yield of crude product based on red phosphorus used is 80 to 85 per cent. 

The yellow layer of phosphorus(V) sulfobromide is then allowed to crystallize, the remainder of the water is removed and the product is dried thoroughly in thin layers on watch glasses in a desiccator over phosphorus(V) oxide. A second water treatment may be necessary if the product is highly colored. Final 3deld of pure PSBrs approximately 60 per cent. 

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