反应详情

Another reference (German Offenlegungsschrift 27 30 371, pp. 18 and 19) describes that 6-chloro-(6H)-dibenz-oxaphosphorin at 130° C. is combined with a large amount of water, the hydrolysis is carded out, the water is distilled off under reduced pressure and the 6-oxo-dibenzoxaphosphorin is then obtained. The operation described is technically very problematical and can hardly be carried out on a large scale, since water vaporizes at 130° C. and cools the reaction mixture. It is therefore necessary to work under increased pressure if the temperature of 130° C. is to be maintained and thus uncontrolled crystallization is to be prevented, since the target compound melts significantly above the boiling point of water.

1. customat 130° C.
2. distillationthe water is distilled off under reduced pressure