Process for making derivatives of vinylphosphonic acid or vinylpyrophosphonic acid

摘要

The disclosure relates to a process for making derivatives of vinylphosphonic acid or vinylpyrophosphonic acid by reacting a ketone with phosphorus trichloride in the presence of phosphorous acid by using the ketone, phosphorous acid and phosphorus trichloride in a molar ratio of 2:1:1, 1 mol phosphorous acid being replaceable by a further mol phosphorus trichloride and 3 mols water.