New antiarrhythmic agents. 7. 2,3-Diaminopropionanilides.

A series of 2,3-diaminopropionanilides was synthesized by acylation of mono- and disubstituted aniline derivatives with 2,3-dibromopropionyl chloride and subsequent amination with the appropriate secondary amines. The target compounds were evaluated in mice for antiarrhythmic efficacy against chloroform-induced tachycardia and for central nervous system toxicity. Several of the active agents were found to have much higher antiarrhythmic potencies than lidocaine, but they were also toxic. Evaluation of the target compounds for local anesthetic activity in the form of sciatic nerve block in rats showed that most compounds had durations of block similar to that of lidocaine; none exhibited the long duration of block seen with etidocaine.