Purification Methods
The acetyl-diamine has been fractionated under reduced pressure and fraction b 125-130o/5mm was refractionated, fraction b 132-135o/4mm was collected and solidified. It is a low melting hygroscopic solid which can be recrystallised from dioxane/Et2O. It is soluble in H2O, Et2O and *C6H6. The p-toluenesulfonate salt can be recrystallised from EtOH/EtOAc (1:8), has m 125-126o but the free base cannot be recovered from it by basifying and extracting with CH2Cl2. The picrate has m 175o (from EtOH) [Aspinall J Am Chem Soc 63 853 1941, Hall J Am Chem Soc 78 2570 1956]. [Beilstein 4 IV 1193.]
