Synthesis
Piperazine-N,N-bis(2-hydroxyethanesulfonic acid) sodium salt (P-2SO3-2Na) was prepared as follows: piperazine (2.15 g, 25 mmol) was dissolved in 20 mLDI water. Then ClCH2CH2SO3Na (9.23 g, 50 mmol) and NaOH (1.60 g, 50 mmol) were added sequentially. The resulting solution was stirred continuously overnight at 40C. A clear solution was formed. The product was obtained by precipitation from cold ethanol and purified from H2O/EtOH. The white powder piperazine-N,N-bis(2-hydroxyethanesulfonic acid) sodium salt was collected after drying (yield >99%).
