The compounds 3-(N-diethylcarbamyl)amino-1-methyl pyrrolidine, 3-(N-carbethoxy-N-methyl)amino-1-methyl pyrrolidine, 1-diethylcarbamyl-3-(N-methyl)amino pyrrolidine and 1-diethylcarbamyl-3-dimethylamino pyrrolidine, said compounds having utility as antifilarial agents.