PROCESS FOR THE PRODUCTION OF PENTAERYTHRITOL DIPHOSPHONATES

摘要

A process for the production of pentaerythritol diphosphonates represented by the general formula (5), characterized by comprising reacting phosphorus tricloride with pentaerythritol in the presence of an inert solvent to form pentaerythritol dichlorophosphite, reacting the penta- erythritol dichlorophosphite with an aralkyl alcohol to form a pentaerythritol diphosphite halide, and heat-treating the pentaerythritol diphosphite halide at a temperature of 80 to 300°C: (5) [wherein Ar<1> and Ar<2> are each aryl; and R<3>, R<4>, R<5> and R<6> are each hydrogen, aryl, or a hydrocarbon group]. According to the invention, specific pentaerythritol diphosphonates useful as flame retardant and so on can be produced at high purity and in high yield by an industrially advantageous process excellent in productivity.