2(S)-Amino-3-[1H-imidazol-4(5)-yl]propyl cyclohexylmethyl ether dihydrochloride and 2(S)-amino-3-[1H-imidazol-4(5)-yl]propyl 4-bromobenzyl ether dihydrochloride
(Cyclohexylmethyloxymethyl)(1H-imidazol-4-iomethyl)-(S)-ammonium dichloride, C(13)H(25)N(3)O(+).2Cl(-), and (4-bromobenzyl)(1H-imidazol-4-iomethyl)-(S)-ammonium dichloride, C(13)H(18)BrN(3)O(+).2Cl(-), are model compounds with different biological activities for evaluation of the histamine H3-receptor activation mechanism. Both title compounds occur in almost similar extended conformations.