the acid itself and this permits a relatively simple means of isolating the salt product generally the process is carried out at an elevated temperature i e between about 60 u00b0 c and 100 u00b0 c then on cooling the salt product crystallizes from solution and is collected on a filter the process is illustrated by the following examples showing the preparation of various salts as indicated of 5 5 bis bromomethyl 2 chloro 2 oxo 1 3 2 dioxaphosphorinane to a solution of 64 8 g 0 2 mol of 5 5 bis bromomethyl 2 hydroxy 2 oxo 1 3 2 dioxaphosphorinane in 250 ml of water at 90 u00b0 c there is added a hot solution 90 u00b0 c of 144 9 g 0 6 mol of aluminum chloride hexahydrate in 100 ml of water the addition is made slowly with stirring and when all is added the resulting mixture is cooled slowly to room temperature and filtered the solid is washed with 50 ml of cold water and dried at 100 u00b0 c under vacuum to constant weight yield 52 3 g 79 of the theory elemental analysis correspond to c 15 h 24 br 6 o 12 p 3 al to a solution of 64 8 g 0 2 mol of 5 5.