7-Azaindole-3-acetic acid derivatives: Potent and selective CRTh2 receptor antagonists

High throughput screening identified a 7-azaindole-3-acetic acid scaffold 7 as a novel CRTh2 receptor antagonist chemotype, which could be optimised to furnish a highly selective compound 13l with good functional potency for inhibition of human eosinophil shape change in whole blood and oral bioavailability in the rat.