Purify it by recrystallisation from pet ether. The m recorded after sublimation was 59.9-60.2o, and 55o after crystallisation from *C6H6/pet ether or pet ether/*C6H6. The (-)-di-O-benzoyl tartrate salt has m 146-148o (from EtOH). [UV, ORD: Harelli & Samori J Chem Soc Perkin Trans 2 1462 1974.] The racemate recrystallises from Et2O with m 74-76o,b 90-94o/1mm. The picrate has m 125-126o (from *C6H6). [Ferles & Attia Collect Czech Chem Commun 38 611 1973, UV, NMR: Nielson et al. J Org Chem 29 2898 1964, Beilstein 21 III/IV 522, 21/2 V 217.]
