Methyl iodide → Diphenyl methylphosphonate

Participants

Reaction Conditions

Reaction Steps

To a three-necked flask equipped with thermometer, magnetic stirrer, distillation head and nitrogen inlet 163 g (0.52 mol) of triphenyl phosphite and 1.0 mL of methyl iodide were charged. Then, 32.7 g (0.26 mol) of trimethyl phosphite was added drop-wise at 100–110° C. over the course of one hour. The reaction temperature was then raised to 210° C. and an exothermic reaction was observed. The reaction temperature was maintained at 230° C. for two hours, and the reaction mixture was analyzed before it underwent transesterification. Diphenyl methylphosphonate was obtained as a liquid. The 31P NMR (CDCl3) indicated 95% diphenyl methylphosphonate. The impurities included triphenyl phosphate (0.8%, δ=−16.4 ppm), trimethyl phosphate (0.6%, δ=−10.3 ppm), and unknown compounds (δ=19.8, 20.4. 28.4 ppm). The acid number of this crude diphenyl methylphosphonate was 5.4 mg KOH/g

Provenance & Evidence