Patent ID: 8846967

Claim:
A process for preparing a fully or partly water-soluble tetraalkyl bisphosphate, in which a) a bis(dichlorophosphate) is reacted with one or more alcohols, b) when in step a) at least 50% of the P—Cl groups present in the bis(dichlorophosphate) have reacted, the reaction mixture from step a) is reacted with a base comprising one or more substances of the formula (Cat n+ ) a (X m− ) b , in which Cat n+ is a cation with a charge of n, X m− is an anion with a charge of m, and a and b are integers which satisfy the condition n×a=m×b, c) water is added to the reaction mixture from step b), d) thereafter a solvent which is different from the alcohol or alcohols used in step a) and which is not fully miscible with water is added to the reaction mixture from step c), to form a mixture consisting of two separate, liquid phases, and e) the phase comprising the tetraalkyl bisphosphate is isolated from the mixture obtained in step d).