Novel Procedure for the Synthesis of 1‐Hydroxy‐1,1‐bisphosphonic Acids using Phenols as Medium

A facile synthetic route for the synthesis of bisphosphonates in phenols is described. Preparations of some of bisphosphonates, which are presently in clinical use such as risedronic acid and alendronate sodium, are synthesized following this new, simple method. This procedure can be useful for the synthesis of this class of bone‐resorptive inhibitors in bulk quantities. Keywords: alendronatebisphosphonatesphenolrisedronic acidsodium saltzoledronic acid Acknowledgment The authors thank the management of Aurobindo Pharma Ltd., Research and Development Department, for supporting this work. The authors also thank members of the Analytical Research Department for their valuable contribution to this work.