Process for preparing organic tertiary polyphosphine monooxides

A process for producing an organic tertiary polyphosphine monooxide which comprises reacting an organic tertiary polyphosphine compound having the general formula ##STR27## wherein each R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7 and R.sub.8 represent an identical or different, substituted or unsubstituted monovalent hydrocarbon radical containing from 1 to 30 carbon atoms, wherein each Y represents an identical or different organic bridging group containing from 1 to 30 carbon atoms selected from the group consisting of hydrocarbon radicals, oxygen containing hydrocarbon radicals, nitrogen containing hydrocarbon radicals and sulfur containing hydrocarbon radicals, wherein a, b and d each represent a value of zero or 1, and wherein c represents an integer of from 1 to 3;

• with an organic monofunctional alkylating agent containing from 1 to 30 carbon atoms selected from the group consisting of monovalent hydrocarbon halides and monovalent hydrocarbon sulfates, in the presence of an inert organic solvent for said organic tertiary polyphosphine compound to form an insoluble monophosphonium salt of said organic tertiary polyphosphine compound;
• hydrolyzing said salt compound with an aqueous alkaline solution to form an organic tertiary polyphosphine monooxide product wherein the oxygenated phosphorous atom of said monooxide product corresponds to the alkylated phosphorus atom of said monophosphonium salt, and recovering the monooxide product so produced.