Improved cyclobutyl nabilone analogs as potent CB1 receptor agonists.

In earlier work, we explored the SAR for the C3 side chain pharmacophore in the hexahydrocannabinol template represented by the drug nabilone, which resulted in the development of AM2389. In an effort for further optimization, we have merged features of nabilone and AM2389 and explored the C3 side chain with varying chain lengths and terminal substitutions. Of the compounds described here, a nabilone analog, AM8936, with the C6'-cyano-substituted side chain, was identified as the most successful analog capable of serving as a potential candidate for further development and a valuable tool for further in vivo studies. AM8936 behaved as a balanced and potent CB1 agonist in functional assays and was a potent and efficacious CB1 agonist in vivo. Our SAR studies are highlighted with the docking of AM8936 on the crystal structure of the hCB1 receptor.