Imidazo[1,2-a]pyrazin-8-ones, imidazo[1,2-d][1,2,4]triazin-8-ones and imidazo[2,1-f][1,2,4]triazin-8-ones as α2/α3 subtype selective GABAA agonists for the treatment of anxiety

Imidazo[1,2-a]pyrazin-8-ones, imidazo[1, 2-d] [ 1, 2,4]triazin-8 -ones and imidazo[2,1-f][1,2,4]triazin-8-ones are high affinity GABA(A) agonists. Compound 16d has good oral bioavailability in rat, functional selectivity for the GABA(A) alpha 2 and alpha 3-subtypes and is anxiolytic in a conditioned animal model of anxiety with minimal sedation observed at full BZ binding site occupancy. (C) 2006 Elsevier Ltd. All rights reserved.