Racemattrennung von Propafenon und Diprafenon, Konfiguration der Propafenon-Enantiomeren
Optical Resolution of Propafenone and Diprafenone, Configuration of Propafenone Enantiomers 
 
 
 
The chiral antiarrhythmic drugs propafenone (rac-1) and diprafenone (rac-3) were resolved by fractional crystallization of the diastereoisomeric salts with optically active di-O, O′-p-toluoyltartaric acid and tartaric acid, respectively. Derivatization with (+)-1-phenylethyl isocyanate and analytical separation of the diastereoisomers 2 and 4 by HPLC confirmed the optical purity of the enantiomers. CD spectra of (+)- and (−)-propafenone as copper complexes established the absolute configuration: (−)-1 is R-, (+)-1S-configurated.