ChemInform Abstract: Novel 1,2,4-Oxadiazoles as Potent and Selective Histamine H3 Receptor Antagonists

Replacement of the isothiourea moiety of known histamine H 3 antagonists by certain 5-membered heteroaromatic systems can give compounds with an improved activity profile. One of these, 3-[(4-chlorophenyl)methyl]-5-[2-(1H-imidazol-4-yl)ethyl] 1,2,4-oxadiazole (GR175737) is a potent, selective, orally active and centally penetrating H 3 antagonist.