disubstituted phenylpyridine derivatives was synthesized and their antiarrhythmic effects against chloroform-induced ventricular arrhythmias in mice were examined. Among them, 2- and 3-[2-(3-aminobutyramido)-4-(2,2,2-trifluroethoxy)phenyl]pyri dines (23h, 24h) and 3-[2-(3-aminobutyramido)-4-ethoxyphenyl]pyridine (24i) showed potent antiarrhythmicactivity. They had approximately twice the potency of mexiletine