Download PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... Combining the first generation H 1 antihistamine chlorpheniramine (1) with H 3 ligands of the alkylamine type has led to the identification of compound 9d, a dual ligand of both the H 1 and H 3 receptors. ... The identification of the dual H 1 /H 3 ligand, 9d, is reported.