PROCESS FOR PREPARING ALKANEPHOSPHONIC ANHYDRIDES

摘要

Process for preparing alkanephosphonic anhydrides of the formula (I) (see formula I) where R is straight-chain or branched unsubstituted C1-C6-alkyl and n .gtoreq. 3, which comprises pyrolytically eliminating water from an alkanephosphonic acid of the formula (II) or a pyroalkanephosphonic acid of the formula (III) (see formula II,III) where R is straight-chain or branched Cl-C6-alkyl, without addition of solvent and removing the water from the reaction mixture by means of an inert gas stream.