From WikiSynth
It has been found that the most favored method is to prepare the hydrochloride using 1.2-1.3 equivalents of HCl in acetonitrile, crystallize, perform a second crystallization from acetonitrile, and finally crystallize from isopropanol to remove traces of acetonitrile. A sample of the dry toluene solution of Grignard product C from Example 2 was concentrated on a rotary evaporator to 18 g. Examination of the sample showed that it contained 15.5 g of amine, the rest being toluene (2.5 g). The sample was stirred in 120 mL of acetonitrile and a solution of 2.6 g of HCl in acetonitrile (29 mL of solution) was added. The temperature was allowed to rise to 42° C., and then to cool. At 29° C. a precipitate started to form. The mixture was stirred 1.5 h further and then filtered at 23° C., followed by a 15 mL acetonitrile wash. Drying in vacuo yielded 12.9 g of the hydrochloride, 99.3/0.7 trans to cis.
