Optical resolution of 1‐(1‐naphthyl)ethylamine by its dicarboxylic acid derivatives: Structural features of the oxalic acid derivative diastereomeric salt pair

Optical resolution methods were established for racemic 1‐(1‐naphthyl) ethylamine. The resolving agents were synthesized by N ‐derivatizing ( R )‐1‐(1‐naphthyl) ethylamine with dicarboxylic acids. Oxalic, malonic, and succinic acid derivatives were found to be suitable resolving agents. These resolutions are parallel to a series of optical resolutions of 1‐phenylethylamine which had been previously performed by our research group using similar derivative resolving agents (Balint et al., Tetrahedron: Asymmetry 2001;12:1511–1518.) The comparison of the results of the enantiomer separations is performed. The diastereomeric salts formed with ( R )‐ N ‐[1‐(1‐naphthyl)ethyl]oxalamic acid were investigated by single crystal X‐ray diffraction. The crystal structures were compared with the previously published structures of the diastereomers of the phenyl‐substituted analogue, namely ( R )‐ and ( S )‐1‐phenylethylammonium ( R ) ‐N ‐(1‐phenylethyl)oxalamates (Balint et al., Tetrahedron: Asymmetry 2001;12:1511–1518.) Chirality, 2009. © 2008 Wiley‐Liss, Inc.