Ethylene → ethylphosphonous acid aluminum(III) salt

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

1500 g (14 mol) of sodium hypophosphite monohydrate are dissolved in 7.5 kg of water and initially charged in a 16 l steel-enamel jacketed pressure reactor. After heating the reaction mixture to 100° C., a reducing valve set to 6 bar is used to introduce ethylene into the reactor up to saturation. While stirring constantly at an ethylene pressure of 6 bar and a temperature of 100-110° C., a solution of 19 g (0.5 mol %) of 2,2′-azobis(2-amidinopropane) hydrochloride in 300 g of water is metered in homogeneously. At a conversion of ethylene of 87.3%, the metered addition of 2,2′-azobis(2-amidinopropane) hydrochloride is stopped and the reactor is decompressed. After cooling to about 90° C., 650 g (4.67 mol of aluminum) of aluminum chloride hexahydrate in 2350 g of water were added within 60 minutes. Subsequently, the resulting solid is filtered off, washed with 2 l of hot water and dried at 130° C. under reduced pressure. The resulting mixture comprises diethylphosphinic acid aluminum(III) salt and ethylphosphonous acid aluminum(III) salt in a ratio of 83.3% by weight of diethylphosphinic acid aluminum(III) salt and 16.7% by weight of ethylphosphonous acid aluminum(III) salt (95.9% yield).

Herkunft & Nachweise