Abstract: The present invention is directed to substituted Pyrazole and Imidazole derivatives of compounds that are antagonists of orexin receptors, and which are useful in the treatment or prevention of neurological and psychiatric disorders and diseases in which orexin receptors are involved or implicated. The invention is also directed to pharmaceutical compositions comprising these compounds and the use of these compounds and compositions in the prevention or treatment of such diseases in which orexin receptors are involved.

Abstract: This disclosure is directed to substituted Imidazolo[2,1-b]oxazole, Imidazolo[2,1-b]thiazole, Imidazolo[2,1-b]oxadiazole, Imidazolo[2,1-b]oxadiathiazole derivatives of compounds that are antagonists of orexin receptors, and which are useful in the treatment or prevention of neurological and psychiatric disorders and diseases in which orexin receptors are involved or implicated. The invention is also directed to pharmaceutical compositions comprising these compounds and the use of these compounds and compositions in the prevention or treatment of such diseases in which orexin receptors are involved.