Recrystallise the sulfate from aqueous EtOH or H2O, although the solubility in the latter is high. The free (-)-base has b 173o/8mm and is steam volatile but resinifies in air. The dipicrate forms yellow needles from EtOH/Me2CO, m 205-206o [Clemo et al. J Chem Soc 429 1931; see also Bolnmann & Schuman The Alkaloids (Ed Manske) Vol 9 175 1967]. The free (±)-base has m 71-72.5o [van Tamelen & Foltz J Am Chem Soc 82 2400 1960]. [Beilstein 23 II 99, 23 III/IV 18.]
