Electrochemical Oxidation of N‐Substituted Iminodimethylenediphosphonic Acids

The electrochemical oxidation of substituted iminodimethylenediphosphonic acids [ RN ( CH 2 PO 3 H 2 ) 2 ] in strong aqueous acid leads cleanly to the secondary amine ( RNHCH 2 PO 3 H 2 ) in most cases. Voltammetric data, NMR data, and the products of the oxidations suggest that unprotonated amine is available for oxidation even in strongly acidic aqueous solution.