An efficient process for synthesizing phosphaplatins in large quantities is disclosed by adding platinum complex to a concentrated pyrophosphate solution at pH from between about 6.0 to 8.5. After stirring, the temperature and pH are lowered to precipitate out desired phosphaplatins. Particularly, the disclosed processes reduce the need to use large volumes of starting materials, and shorten the reaction time. In addition, disclosed is a process for recycling un-reacted materials from a first phosphaplatins synthesis.
