Sulfuric Acid → Hydrochloric Acid

Participants

Reaction Steps

354 g of N-hydroxymethyl phthalimide, dissolved in 1100 g of dichlorethane, are heated for 5 hours to reflux temperature with 227 g of acetic acid anhydride. 150 g of a styrene polymer crosslinked with 4 % of divinyl benzene are swollen in this ester solution over a period of 30 minutes at 60° C. 240 g of concentrated sulphuric acid are then added dropwise over a period of 1 hour at reflux temperature, and the reaction mixture is stirred at the same temperature for a period of 20 hours. After the reaction product has been separated off, it is suspended in 1000 ml of 10 % aqueous ammonia solution. The residues of dichlorethane are removed from this suspension by azeotropic distillation. The reaction product is then separated off and hydrolysed by heating for 10 hours to 180° C with 40 % sodium hydroxide solution in an autoclave. After the sodium hydroxide has been washed out, a weakly basic anion exchanger is obtained with an acid-binding capacity of 3.0 Val/1 for N/10 hydrochloric acid and a nitrogen content of 10.4 % in the dry material.

Provenance & Evidence