Patent ID: 7435841

Claim:
A process for producing halohydocarbyl phosphonic acid diesters of the formula (I): in which Z is halogen; X and Y are hydrogen; the halogen has an atomic weight greater than 30; and R and R 1 are the same or different and are hydrocarbyl groups; which process comprises reacting a trihydrocarbyl phosphite of the formula (II): in which R and R 1 are the same or different and have the meanings given under formula (I); R 2 has the same meaning as R and R 1 given under formula (I) and is the same or different from either R or R 1 ; with a hydrocarbyl halide of the formula (III): in which Z, X and Y have the meaning given in formula (I), and W is a halogen having an atomic weight greater than 30; in the presence of an effective amount of a polarity lowering additive selected from the group consisting of benzene, toluene, xylene, and alkane, the alkane selected from the group consisting of pentane, hexane, heptane, octane, and their isomers; wherein the molar ratio of the hydrocarbyl halide reactant to the trihydrocarbyl phosphite reactant is greater than from 2:1.