Purification Methods
The (±)-isomer is purified by repeated distillation ( b 102-104o/12mm, 108-110o/18mm), and the (±)-picrate crystallises from EtOH with m 140-141o. The R(+)-enantiomer has b 70o/0.6mm and [] D +5.6o (c 3.63, MeOH). Its hydrochloride has a negative rotation and its dimethiodide has m 230o and [] 24 -8.02o. [Suyama & Kanno Yakugaku Zasshi (J Pharm Soc Japan) 85 531 1965, Uno et al. J Heterocycl Chem 24 1025 1987, Flanagan & Joullie Heterocycles 26 2247 1987, Beilstein 21 III/IV 44.]
