Process for producing dialkylphosphinic acid and aluminum salt of diphosphinic acid

摘要

A process for preparing aluminum salts (I) of dialkylphosphinic acids or (formula (II)) of alkylated diphosphinic acidswhereR1 and R2 are a linear or branched C1-C8-alkyl radical andR3 is a linear or branched C1-C10-alkylene radical or an arylene radical or an alkylarylene radical or an arylalkylene radical,which comprises reacting a dialkylphosphinic acid ester of the formula (III) or a diphosphinic acid ester of the formula (IV)whereR1, R2 and R3 are as defined above andR4 is a linear or branched C1-C8-alkyl radical,in the presence of a saturated aliphatic monocarboxylic acid having a total of from 1 to 7 carbon atoms, with aluminum hydroxide at a temperature of from 150 to 350° C.