S-2-Amino-3-methyl-l-butanol (CAS NO. ) is purified by vacuum distn using short Vigreux column.

Alternatively it is purified by steam distn. The steam distillate is acidified with HCl, the aq layer is collected and evapd. The residue is dissolved in butan-1-ol, filtered and dry Et₂O added to cryst the hydrochloride salt (hygroscopic), m 113 °C. The free base can be obtained by suspending the salt in Et₂O adding small vols of satd K₂CO₃ until effervescence is complete and the mixture is distinctly alkaline. At this stage the aqueous layer should appear as a white sludge. The mixture is heated to boiling and refluxed for 30 min (more Et₂O is added if necessary). The Et₂O is decanted off from the white sludge, the sludge is extracted twice with Et₂O (by boiling for a few minutes), the combined organic layers are dried (KOH pellets), evapd and the residue distd in a vacuum.