1-Aryl-5-(1H-pyrrol-1-yl)-1H-pyrazole-3-carboxamide: An effective scaffold for the design of either CB1 or CB2 receptor ligands

New 1-aryl-5-(1H-pyrrol-1-yl)-1H-pyrazole-3-carboxamides were synthesized as cannabinoid (CB) receptor ligands. Compound 11 (CB1 K-i = 2.3 nM, CB1 SI = 163.6) showed CB1 receptor affinity and selectivity superior to Rimonabant and AM251. Acute administration of 2 mg/kg 11 reduced sucrose, but not regular food, intake in rats. On the other hand, compound 23 (CB2 K-i = 0.51 nM, CB2 SI =30.0) showed significant affinity and selectivity for the CB2 receptor. The results presented here show that the 1-aryl-5-(1H-pyrrol-1-yl)-1H-pyrazole-3-carboxamide may serve as an effective scaffold for the design of either CB1 or CB2 receptor ligands. (C) 2011 Elsevier Masson SAS. All rights reserved.