A One-Pot Synthesis of 1-Hydroxy-1,1-bis(phosphonic acid)s Starting from the Corresponding Carboxylic Acids

By starting with various carboxylic acids, a one-pot procedure for the synthesis of the corresponding 1-hydroxy-1,1-bis(phosphonic acid)s is reported. The efficiency of this simple methodology is illustrated by synthesizing well-known marketable amino hydroxy bis(phosphonate)s such as alendronate or N-methyl pamidronate without additional steps for the protection/deprotection of the amine function.