PROCESS FOR THE PRODUCTION OF PENTAERYTHRITOL DIPHOSPHONATES

摘要

A process for producing a pentaerythritol diphosphonate represented by the formula (5) characterized by (A) reacting phosphorus trichloride with pentaerythritol in the presence of an inert solvent to obtain pentaerythritol dichlorophosphite (reaction (a)), (B) reacting the pentaerythritol dichlorophosphite with an aralkyl alcohol to obtain a pentaerythritol diphosphite (reaction (b)), and (C) heat-treating the pentaerythritol diphosphite in the presence of a halogenated compound on the condition of a temperature of from 80 to 300°C (reaction (c)): wherein Ar¹ and Ar², which may be the same as or different from each other, each represents a substituted or unsubstituted aryl group having from 6 to 20 carbon atoms, and R³, R⁴, R⁵ and R ⁶ which may be the same as or different from each other, each represents a hydrogen atom, a substituted or unsubstituted aryl group having from 6 to 20 carbon atoms, or a saturated or unsaturated hydrocarbon group having from 1 to 20 carbon atoms.;According to the production process of the invention, a particular pentaerythritol diphosphonate capable of being utilized as a fire retarding agent and the like can be provided with high purity and high yield by an industrially advantageous process excellent in productivity.