Recent advances in CB1 cannabinoid receptor antagonists

Cannabinoid CB, receptor antagonists are currently the subject of intensive research due to their highly promising therapeutic prospects. Novel chemical entities having CB, antagonistic properties have recently been disclosed by several pharmaceutical companies and some academic research groups, some of which are close structural analogs of the leading compound rimonabant (SR-141716A; Sanofi-Synthilabo). A considerable number of these CB, antagonists are bioisosteres that are derived from rimonabant by the replacement of the pyrazole moiety with an alternative heterocycle. As well as these achiral compounds, Solvay Pharmaceuticals have disclosed a novel class of chiral pyrazolines that are potent and CB1/CB2 subtype-selective cannabinoid receptor antagonists, in which the interactions with the CB, receptor are highly stereoselective.