J I-Amino-N-i2-morphoIinocthyl)-2,6-dimethyllxnraniide. -1-amino-N-(2-pi~~ridiiioethyl)-2.6-diniethylbenzamide, 4aminci-N-['-(4-phenyl-Ipiperazino)ethyl]-2,6-dimethylbenzarnide, and 4-aniino-N-[2-(3-azabicyclo[3.2.2]1ionano)ethyl]-2,~dimetliyl- benzaniide were synthesircd as potential antiarrhythmic agents. These conipounds were found to be capable of prolonging the effective refractory period of the isolated rabbit atria. They also demonstrated prophylactic activity against ouabain. In addition. 4-amino-N-(2-piperidinoethyl)-2.6-dimethylhenzamide was able to terminate ouabain-induced arrhythmia. and 4-amino-N-(2-mor-pholinoetIiyl)-2.6-dimethylbenz~mide was active in antagonizing aconitine-evoked arrhythmia. The four compounds. especially 4aminn-N-[2-(?-aral~icyclo[3.2.2]nonano)ethyl]-2,6-dime t hyl benzamidc. also Showed some degree of local anesthetic activity i n the corneal retlex test i n rabbits. The pKa and LDjo values of the compounds were determined. Key phrases 3-Amino-N-[2-(su bs ti t u ted amino)et hyl]-2,6-dimethylbenianiides . -synthcsired as potential antiarrhythmic agents r_' An tiarrh y t hmic agents, PO tent ial -syn thesis of 4-amino-N-[2-(substituted aniino)ethyl~-2.h-dimethylbenzamides