Ethanolamine → 1-Propanesulfonic acid, 3-[(2-hydroxyethyl)amino]-

N-(β-hydroxyethyl)-3-aminopropanesulfonic acid, ##STR9## was prepared as follows: 366 parts ethanolamine and 1000 parts methanol were cooled to 10° C. in a three-necked, round-bottom flask which was fitted with a stirring bar, thermometer, and a dropping funnel. 244 parts propane sultone dissolved in 1000 parts methanol were added via the dropping funnel at such a rate that the flask temperature did not increase above 20° C. After the addition was completed, the contents of the flask were stirred for two hours, concentrated to a thick slurry, and then added to 2400 parts isopropyl alcohol. The resulting solid was filtered, rinsed with 500 parts isopropyl alcohol and dried to give 240 parts of the desired product.