sodium hydroxide in water boiling (10 min/aq. NaOH); formation of sodium imidobis(sulfate); treatment with concd. H2SO4;; sepn. from Na2SO4 by extraction (acetone);;
sodium hydroxide in water boiling (10 min/aq. NaOH); formation of sodium imidobis(sulfate); treatment with concd. H2SO4;; sepn. from Na2SO4 by extraction (acetone);;