[Figure 6]
After the filtration of the cation exchange resin beads, the desorption was carried out using a mixture of 5% NaOH and cyclopentyl methyl ether (CPME) in a volumetric ratio of 1:1. After the phase separation the product amine was oiled out from the ether phase as the hydrochloride salt using gaseous HCl. Herein, CPME offers a relatively low water content with the organic layer, which is highly important to precipitate the hydrochloride-salt of the amine. After evaporating the residual CPME, ca. 1 g of a brown-orange oil was obtained with a purity of >99% (see Figure S 7 to Figure S 10 for further information). Any further purification steps, e.g. by column chromatography or recrystallization, were not required highlighting the applicability of this method.