During the course of study of variations in the basic moiety of heptacainium chloride 10 derivatives of 4-alkylpiperazinoethyl esters of o-heptyloxyphenylcarbamic acid were prepared. Pharmacological investigation indicated that practically all the new compounds were several times more active than standards (cocaine and procaine). The most effective compound was 1-[2-(o-heptyloxyphenylcarbamoyloxy)ethyl]-4-butyl-piperazinium dichloride, which was 142 times more active than cocaine and 266 times more active than procaine.