The general procedure for the synthesis of N-(2-hydroxyethyl)piperazine-N'-(2-ethanesulfonic acid) sodium salt from N-hydroxyethylpiperazine and sodium 2-hydroxyethanesulfonate is as follows: magnetic stirring in a 70-mL fluoropolymer-lined steel autoclave equipped with internal thermocouples for monitoring the temperature of the liquid phase, a pressure gauge, a pressure-reducing valve, and an exhaust valve. First, amine feedstock, anhydrous or aqueous sodium 2-hydroxyethanesulfonate solution, and anhydrous or aqueous sodium hydroxide solution were added to the open-topped autoclave. Subsequently, the autoclave was assembled and immersed in an electrically heated oil bath. The stirred reaction mixture was rapidly heated to the specified reaction temperature with the exhaust valve closed and maintained at that temperature for the time specified in Examples 9, 10 and 13. Upon completion of the reaction, the mixture was cooled to room temperature, the reactor was opened, and the reaction product was dissolved in a sufficient amount of water to ensure complete dissolution of all solids.
