It is distilled at high vacuum, then recrystallised from pet ether. Keep it under N2 in sealed tubes in the dark at 0o. The hydrochloride [5949-24-6] M 166.6 crystallises from EtOH/Et2O and has m 156-158o (yellow monohydrate), and dehydrates on sublimation at 110-115o/3mm. The picrate has m 196-196.5o. [Beilstein 23 H 173, 23 III.IV 1217.]
