Process for preparing phosphinic esters

摘要

The present invention relates to a process for preparing phosphinic esters which comprises a) reacting elemental yellow phosphorus with alkyl halides in the presence of alkali metal hydroxide or alkaline earth metal hydroxide to form a mixture which comprises as main constituents the alkali metal salts and/or alkaline earth metal salts of alkylphosphonous acid, phosphorous acid and hypophosphorous acid b) removing the alkylphosphonous acid from the mixture obtained as described in a), c) esterifying the alkylphosphonous acid, d) adding the resultant ester of the alkylphosphonous acid to a compound having at least one C=C double bond. The invention likewise relates to the use of the phosphinic esters prepared by this process inter alia as flame retardants and as precursor for further syntheses.