Synthesis, SAR and intramolecular hydrogen bonding pattern of 1,3,5-trisubstituted 4,5-dihydropyrazoles as potent cannabinoid CB(1) receptor antagonists.

The synthesis, structure-activity relationship (SAR) studies and intramolecular hydrogen bonding pattern of 1,3,5-trisubstituted 4,5-dihydropyrazoles are described. The target compounds 6-18 represent a novel class of potent and selective CB(1) receptor antagonists. Based on X-ray diffraction data, the orally active 17 is shown to elicit a different intramolecular H-bonding mode as compared to ibipinabant (3) and SLV330 (4).