Application WO2012081692 from Taisho Pharmaceutical Co. Ltd. claims 
pyrazole-based antagonists of the orexin-1 and orexin-2 receptors. Utility in a 
number of therapeutic areas is claimed, including the treatment of sleep 
disorders; the most likely use of the claimed compounds. Data from in vitro 
functional assays are presented, with the claimed compounds typically being dual 
orexin receptor antagonists (DORAs) or having moderate selectivity for orexin-1. 
Structurally, the claimed compounds represent a variation on established DORA 
SAR themes and translate features of clinical compounds into a pyrazole-based 
scaffold. Example 52, the most potent molecule in the application, has similar 
molecular weight and lipophilicity to suvorexant, the most advanced DORA, with 
broadly comparable potency in functional assays.