Water miscible solvent based process for purifying a bisphosphate

A process for purifying hydroquinone bis-(diphenylphosphate) comprising:

• solvating molten hydroquinone bis-(diphenylphosphate) in a mixture of water and water miscible solvent at a temperature of at least 30 degrees Celsius or adding solid hydroquinone bis-(diphenylphosphate) to water and a water miscible solvent to a temperature sufficient to solvate the hydroquinone bis-(diphenylphosphate);
• cooling the solution over a period and to a temperature that provides for crystallization of hydroquinone bis-(diphenylphosphate) solid product;
• increasing the pH of the solution prior to, and/or during, and/or after the initiation of crystallization, and/or after crystallization of the product is complete, by the addition of a base;
• and after crystallization is complete,
• separating hydroquinone bis-(diphenylphosphate) solid product from the solution;
• washing the separated hydroquinone bis-(diphenylphosphate) solid product in the same and/or different mixture of water and water miscible solvent;
• and,
• washing the hydroquinone bis-(diphenylphosphate) solid product which has been washed in the mixture of water and water miscible solvent, with water.