Synthesis and pharmacological evaluation of 4,4-disubstituted piperidines.

A new class of piperidine derivatives is added to the increasing family of compounds related to fentanyl and carfentanil. Herein, we describe the synthesis and pharmacology of a number of 1-(arylethyl)-4-(acylamino)-4-[(acyloxy)-methyl]piperidines such as 9, 15, and 23. As expected, many of these congeners of fentanyl are extremely potent narcotic agonists.