Abstract: Crude dihydrocarbylchlorothiophosphate product contaminated with dihydrocarbylpolysulfide and/or dihydrocarbylchlorophosphate is upgraded by treating the crude product with an aqueous hypochlorite solution, and separating an aqueous phase from the organic, then drying to obtain the resultant product.

Abstract: Crude dihydrocarbylchlorothiophosphate product contaminated with dihydrocarbylpolysulfide and/or dihydrocarbylchlorophosphate is upgraded by treating the crude product with chlorine followed by an aqueous solution of reducing agent, separating an aqueous phase from the organic, then drying to obtain the resultant product.

Abstract: A method of preparing diarylchlorophosphate comprising the step of reacting alkyldiarylphosphate represented by formula (1) and thionyl chloride in the presence of a catalyst:R.sup.1 O--P(O)(OAr).sub.2 (1)(where R.sup.1 represents an alkyl group having 1 to 4 carbon atoms, and Ar represents a substituted or unsubstituted aryl group). According to the invention there is provided a method of preparing diarylchlorophosphate having a high purity at a high yield, which can be advantageously used in industrial applications.

Abstract: An improvement in the process for making a dialkyl phosphorochloridothioate from P.sub.2 S.sub.5, alkyl alcohol and chlorine in which the desired product is separated from the reaction mixture by distillation, leaving an unstable, acidic residue, wherein the residue is stabilized and neutralized by reaction with an organic base, thereby enhancing the value of the residue while avoiding potential environmental damage caused by disposal of the residue.

Abstract: This invention relates to a novel process for preparing bis(aryl)phosphorohalidates which are useful in the synthesis of various enol phosphates. The process of this invention provides a means of producing a high-yield, high-purity product without the need for costly crystallization or impractical, high temperature distillations.

Abstract: Organophosphorus compounds are stabilized against decomposition during and after recovery from their synthesis reaction mixtures by the addition to the synthesis reaction mixture of at least 0.5% by weight of an acid scavenger, based on the weight of the organophosphorus compound, before allowing the organophosphorus compound to crystallize. The invention is of particular value in the stabilization of 2,2'-alkylidenebis(dialkylphenyl)fluorophosphonites, such as 2,2'-ethylidenebis(4,6-di-t-butylphenyl)fluorophosphite, which is rendered more suitable for use as a stabilizer for organic polymers, e.g., polycarbonates, by the practice of the invention.