Studies on Naphthalenealkylamines for Medical Purpose. : III. Local Anesthetic Action of 2-Naphthalenealkylamines

Abstract

Local anesthetic action of recently synthesized 2-naphthalenealkylamines was tested. Surface anesthetic action was tested by the corneal reflex of a guinea pig and N-alkyl-N-methyl-2-naphthaleneethyl (or propyl) amines (XIb∼f, XIIb∼f) all showed activites stronger than that of procaine, and N-methyl-N-pentyl-2-naphtha1eneethylamine (XIf) was especially strong, the potency being 16 times that of procaine. The activity decreased when the compounds of this series were derived to methiodide, and only the N-butyl and N-pentyl compounds showed a weak activity. This fact seems to indicate the possibility that the base of a compound takes part in appearance of the activity. Primary amines (IIa to Xa) generally had strong irritant psoperty N, N-Dimethyl derivatives (IIb to Xb) showed the activity only when the number of carbon atoms in the side chain was 2 (IVb) or 3 (Vb), and all higher homologs had strong toxicity necrosis. Conduction anesthetic activity was examined with frog sciatic nerve in compounds of XI and XII series and their potency was compared with that of procaine. Approximately similar structure-activity relationship as in the case of surface anesthetic activity was found.