Highly diastereoselective synthesis of enantiopure naphthylaminoalcohols with analgesic properties

The diastereoselective synthesis via Grignard reaction of enantiopure analgesic naphthylaminoalcohols has been performed. The chiral racemic key intermediate 3-dimethylamino-2-methyl-1-(naphthalen-2-yl)propan-1-one and enantiomers were prepared and transformed into the desired compounds by addition of the organometallic reagent. The chemical characterization of all diastereoisomers was accomplished by 1H NMR and HPLC analyses and the absolute configuration assigned by CD spectroscopy. The in vitro and in vivo profile has also been evaluated.