The influence of esters and carboxylic acids as the N-substituent of opioids. 1. Benzomorphans

To investigate the effects of carboxylic ester and acid moieties as the N -substituent of opioids, a short series of racemic N -substituted normetazocines was prepared. The introduction of both groups as the normetazocine N -substituent produced compounds which displayed low potency in vitro and in vivo , with the esters displaying the greater activity. The pharmacology of the compounds is discussed with implications resulting from potential in vivo metabolic hydrolysis.