Abstract: Seven target compounds were designed and synthesized according to the structure of lead compound—desloratadine.The structures of the compounds were identified by ¹H NMR and HR-MS.The in vitro results based on histamine-induced contraction of guiea-pig ileum showed that zwitterionic compound 9c had stronger antihistamine activity than positive control desloratadine.The human ether-à-go-go related gene （hERG）inhibition and guinea-pig langendorff model indicated that compound 9a had low inhibitory activity on hERG and yet no effect on the period of electrocardiogram,demonstrating that compound 9a may not cause the potential cardiotoxicity.