Local anesthetic activity of mixtures of cis- and trans-(2-dimethylaminomethylcycloheptyl)-2-alkoxyphenylcarbamates.

In a previous study, we synthesized two homologous series of racemic stereoisomeric cis- and trans-(2-dimethylaminomethylcycloheptyl)-2-alkoxyphenylcarbamates with alkyl chain lengths ranging from C1 to C8 and analyzed their local anesthetic activity. Here, we show that the local anesthetic activities of mixtures of cis-1 and trans-1 stereoisomers are higher than the sum of activities calculated for the individual stereoisomers at all molar fractions. We conclude that an appropriate ratio of cis- and trans-stereoisomers is necessary to achieve the maximum anesthetic activity of the studied stereoisomeric carbamates.