2,3‐Dihydro‐1‐Benzofuran Derivatives as a Series of Potent Selective Cannabinoid Receptor 2 Agonists: Design, Synthesis, and Binding Mode Prediction through Ligand‐Steered Modeling

Abstract
We recently discovered and reported a series ofN‐alkyl‐isatin acylhydrazone derivatives that are potent cannabinoid receptor 2 (CB2) agonists. In an effort to improve the druglike properties of these compounds and to better understand and improve the treatment of neuropathic pain, we designed and synthesized a new series of 2,3‐dihydro‐1‐benzofuran derivatives bearing an asymmetric carbon atom that behave as potent selective CB2agonists. We used a multidisciplinary medicinal chemistry approach with binding mode prediction through ligand‐steered modeling. Enantiomer separation and configuration assignment were carried out for the racemic mixture for the most selective compound, MDA7 (compound18). It appeared that theS enantiomer, compound MDA104 (compound33), was the active enantiomer. Compounds MDA42 (compound19) and MDA39 (compound30) were the most potent at CB2. MDA42 was tested in a model of neuropathic pain and exhibited activity in the same range as that of MDA7. Preliminary ADMET studies for MDA7 were performed and did not reveal any problems.