Tricyclic aminopyrimidine histamine H4 receptor antagonists.

This report discloses the development of a series of tricyclic histamine H4 receptor antagonists. Starting with a low nanomolar benzofuranopyrimidine HTS hit devoid of pharmaceutically acceptable properties, we navigated issues with metabolism and solubility to furnish a potent, stable and water soluble tricyclic histamine H4 receptor antagonist with desirable physiochemical parameters which demonstrated efficacy a mouse ova model.