Method for the preparation of mono- or poly [dialkyl or dicycloalkylphosphonylmethyl] aromatic carbocyclic compounds

A method for the preparation of a phosphine oxide represented by the formula:

• ##STR5## wherein R represents an alkyl radical containing from 1 to 8 carbon atoms or a cycloalkyl radical containing 5 or 6 carbon atoms in a ring, said ring optionally being further substituted with one or more lower alkyl (C.sub.1 to C.sub.4) groups;
• R.sup.1 and R.sup.2 are, individually, methyl, ethyl, or methoxy radicals;
• AR is benzene or naphthalene;
• and when AR is benzene, m and n are, individually, integers from 0 to 5, inclusive, and x is an integer from 1 to 6, inclusive;
• when AR is naphthalene, m and n are, individually, integers from 0 to 3, inclusive, and x is an integer from 1 to 4, inclusive, which comprises:
• 1. reacting a secondary phosphine compound of the formula:
• (R).sub.2 PH
• with at least a stoichiometric amount of formaldehyde to produce a dialkylhydroxymethylphosphine of the formula:
• (R).sub.2 P -- CH.sub.2 OH
• 2. reacting at least the stoichiometrically required amount of said dialkylhydroxymethylphosphine with a halomethyl aromatic compound of the formula:
• ##STR6## wherein X is a halogen atom, to produce a tertiary phosphine of the formula:
• ##STR7##
• and 3. oxidizing said tertiary phosphine compound.