Hydrogen Peroxide → ethylphosphonous acid aluminum(III) salt

Participants

Reaction Conditions

Reaction Steps

1500 g (14 mol) of sodium hypophosphite monohydrate and 35 g of concentrated sulfuric acid 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 3 bar and a temperature of about 100° C., a solution of 80 g (5 mol %) of hydrogen peroxide (33% by weight) in 300 g of water is metered in homogeneously. At a conversion of ethylene of 90%, the metered addition of hydrogen peroxide is stopped and the reactor is decompressed. After cooling to about 90° C., 746 g (4.67 mol of aluminum) of aluminum acetate in 2254 g of water are 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 88.6% by weight of diethylphosphinic acid aluminum(III) salt and 11.4% by weight of ethylphosphonous acid aluminum(III) salt (92.6% yield).

Provenance & Evidence