Exploring Monohalogen-Substituted Phenylethylamine Hydro-Chloride Salts: Preparation and Solid Phase Analysis of Pharma-Ceutical Building Blocks and Resolving Agents

Monohalogen-substituted (F-, Cl-, Br-) phenylethylamine derivates are a valuable class of chiral compounds, e.g., for C-C-coupling reactions, which are the basis for multiple pharmaceuticals and resolving agents. Here, the solid phase behavior of the underlying phenylethylamine derivates, especially of the corresponding hydrochloride salts, is highly relevant as those compounds are often applied in enantiopure form during the production processes. In this study, the solid phase behavior of 20 synthesized chiral phenylethylamine hydrochloride derivates (both enantiomers and racemates) was investigated including detailed information regarding melting behavior, powder X-ray diffraction data and the type of the chiral system present. Further, the binary melt phase diagram of a found conglomerate system and two novel enantiomer crystal structures were determined. This study is aimed at revealing structure–phase behavior relationships for the 20 monohalogen-substituted compounds investigated as well as providing basic solid–phase-related data required for later crystallization-based enantioseparation processes.