Patent ID: 8471066

Claim:
A process for preparing a phosphoromonochloridite comprising contacting phosphorus trichloride (PCl 3 ) with an aromatic diol represented by the formula: wherein: m is zero, 1 or 2; R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are each independently selected from hydrogen, halogen, and C 1 -C 10 substituted or unsubstituted hydrocarbyl moieties; and wherein optionally, R 2 can be bonded to R 3 to form a substituted or unsubstituted hydrocarbylene moiety so as to form a 5- or 6-membered ring; and/or optionally, R 4 can be bonded to R 5 to form a substituted or unsubstituted hydrocarbylene moiety so as to form a 5- or 6-membered ring, in a slurry comprising a portion of the aromatic diol in solid form and comprising a solution phase comprising the remaining portion of the aromatic diol and an organic solvent, wherein the slurry comprises less than 5 mole percent of a nitrogen base, calculated on total moles of the aromatic diol, wherein the organic solvent has a low hydrogen chloride solubility, wherein the molar ratio of the PCl 3 to the aromatic diol is greater than about 1.0/1 to less than 3.5/1; and wherein the organic solvent is used in an amount of from greater than about 20 percent to less than about 95 percent of the slurry by weight, based on the weight of the slurry; the contacting being conducted under reaction conditions sufficient to produce a phosphoromonochloridite represented by the formula: wherein m and R 1 through R 8 have the definitions given hereinabove, with the proviso that the reaction time is from greater than about 3 hours to less than about 48 hours, that greater than about 95 mole percent of the aromatic diol is converted in the reaction, and that the contacting is conducted at a reaction temperature from greater than about 25° to less than 75° C.