经典的抗组胺药具有镇静作用,因而限制了其应用,寻找无镇静作用的H_1-拮抗剂仍是制药工业研究的目的。最近,在抗组胺药azatadine的结构改造中,将其碱性叔氨基官能团改变为中性的氨基甲酸酯官能团,使之保留了显著的抗组胺作用,却没有或很少有中枢神经系统的副作用,在这一系列化合物中具强效抗组胺作用的loratadine由于无中枢神经系统副作用被选出作进一步的评价。合成本品的合成有两条途径:(1)由 Classical antihistamines have a sedating effect that limits their utility and finding H 1 -agonists without any sedative effect is still the goal of the pharmaceutical industry. Recently, the structural modification of the antihistamine azatadine changed its basic tertiary amino functionality to a neutral carbamate functionality, leaving it with a significant antihistamine effect with little or no central nervous As a side effect of the system, loratadine with potent antihistamine action in this series of compounds was selected for further evaluation due to absence of central nervous system side effects. Synthetic synthesis of the product has two ways: (1) from