Crystallise glycylglycine from aqueous 50% EtOH or water at 50-60o by addition of EtOH. Dry it at 110o. It sublimes at 190-200o/0.3mm with 30% recovery [Gross & Gradsky J Am Chem Soc 77 1678 1955, King J Am Chem Soc 79 6153 1957]. [Beilstein 4 IV 2459.]