3-amino-N-(2-hydroxyethyl)benzenesulfonamide → 2-[(3-Aminobenzene-1-sulfonyl)amino]ethyl hydrogen sulfate

Participants

Reaction Steps

216 g of 3-amino-N-(2-hydroxyethyl)-benzenesulphonamide are stirred into 0.4 liter of sulphuric acid monohydrate at 0°-5° C., whilst cooling. The mixture is subsequently stirred, first at 0°-5° C. for 1 hour and then at 15°-20° C. for 3 hours. The solution is then discharged onto about 2.5 liters of ice-water, the temperature being kept below 5° C. The resulting precipitate is allowed to settle, the sulphuric acid solution is largely distilled off, the reaction product is filled up to a volume of about 1 liter with ice-water, the mixture is neutralised by adding 45.0% strength sodium hydroxide solution dropwise, whilst cooling, and the resulting precipitate is filtered off. It is washed with a little water and can be employed in the subsequent diazotisation reaction as a moist paste. If the precipitate is dried, about 200 g of sulphuric acid mono-N-(3-amino-phenylsulphonyl)-2-aminoethyl ester are obtained. ##STR17##

Provenance & Evidence