Constitution and pharmacological activity of N-aminoacylephedrines, a new class of local anesthetics

Abstract

Reaction of ephedrine or amphetamine with mixed anhydrides of dialkylamino acids and carboxylic acid half esters yields a novel series of acyl derivs. which have local anesthetic activity. Their mechanism of activity is discussed. The acyl derivs. synthesized [Arch. Pharm. 296(1), 33-7(1963)], e.g. N-(DL-N-dimethylphenylalanyl)-L-y-ephedrine, are sepd. into diastereoisomers by the Craig countercurrent method. By detailed sepn. and study of the constellations of the isomeric mols., using ir spectroscopy and dissocn. const. measurements, a relation between molecular shape and local anesthetic activity is tentatively established, provided the compd. is sufficiently sol. in the lipoid fraction, in dog corneas (Tammelin and Lofgren, CA 42, 7443i).