Purification Methods
It crystallises in hexagonal plates from MeOH and H2O. [Klosterman & Painter J Am Chem Soc 69 2009 1949.] The L-isomer [3211-76-5] is purified by dissolving it in H2O, adjusting the pH to 5.5 with aqueous NH3, evaporating to near-dryness, and the residue is washed several times with absolute EtOH till a solid is formed and then recrystallise from Me2CO. It has m 266-268o(dec) [also 275o(dec)], and [] D +18.1o(c 1, N HCl). [Pande et al. J Org Chem 35 1440 1970, Beilstein 4 IV 3216.]
