[Local anesthetics. CVI. Preparation and effect of (+/-)-trans-[2-(piperidinomethyl) cyclopentyl] alkyl, alkoxy and halogen substituted esters of phenylcarbamic acid].

Within the framework of the research of potential local anaesthetics, five compounds from the group of (+/-)-trans-[2-(piperidino-methyl)cyclopentyl]alkyl, alkoxy and chloroalkyl esters of phenylcarbamic acid were prepared. The final compounds were obtained by addition of (+/-)-trans-2-(piperidinomethyl)cyclopentanol to the corresponding substituted phenylisocyanates. They were isolated in the form of salts with hydrochloric acid. Their structure was confirmed on the basis of interpretation of the results of UV and IR spectra. A pharmacological evaluation revealed that the final compounds were more effective than the employed standards cocaine and procaine, but they did not achieve the expected effect in comparison with the pattern compound pentacaine. The index of local-anaesthetic efficacy ranges from 1 to 8 in surface anaesthesia and 1 to 12 in infiltration anaesthesia. It is substantially lower even in comparison with analogical basic esters of alkoxyphenylcarbamic acid.