Local Anesthetics: 2-N,N-Dialkylaminoacyl-2'-methyl (or 2',6'-dimethyl)-4'-butylaminoanilides

A series of tetracaine analogs based on the lidocaine structure, having a 2'-methyl-(or 2',6'-dimethyl)-4'-butylaminoanilide moiety with α substitution on the dialkylaminoacyl function, has been synthesized. Local anesthetic activity was found with the N-butyl derivatives in both the 2'-methyl and 2',6'-dimethyl series using both the method of rabbit cornea loss of reflex and spinal anesthesia in sheep. Duration of activity of the compounds was greater than that of lidocaine, but less than that of tetracaine, with comparable dosage levels.