A process for stereospecific preparation of bepotastine of formula (I) and novel intermediates used therein having formulae (II) to (IV) are provided. The inventive process comprises subjecting (RS)-4-[(4-chlorophenyl)(2-pyridyl)methoxy]piperidine to a reaction with a 4-halobutanoic acid l-menthyl ester, halo being chloro, bromo or iodo, in an organic solvent in the presence of a base to produce (RS)-bepotastine l-menthyl ester of formula (II), conducting a reaction of the compound of formula (II) with N-benzyloxycarbonyl L-aspartic acid in an organic solvent to induce selective precipitation of bepotastine l-menthyl ester.N-benzyloxycarbonyl L-aspartate of formula (III), filtering the precipitates formed in step 2) to isolate the compound of formula (III), treating the compound of formula (III) with a base to liberate bepotastine l-menthyl ester of formula (IV), and hydrolyzing the compound of formula (IV) in the presence of a base. The inventive process can provide bepotastine having a high optical purity of not less than 99.5% in a high yield, and thus, is useful in the development of anti-histamines and anti-allergic agents.
提供了一种用于立体特异性制备
化学式(I)的
倍他司汀以及在其中使用的具有
化学式(II)至(IV)的新型中间体的方法。这种创新的方法包括将(RS)-4-[(4-
氯苯基)(2-
吡啶基)甲氧基]
哌啶与一种有机溶剂中的碱反应,生成(RS)-
倍他司汀l-薄荷酸薄荷酯化合物(II),然后将化合物(II)与
N-苄氧羰基
L-天冬氨酸酸在有机溶剂中反应,诱导
倍他司汀l-薄荷酸薄荷酯的选择性沉淀。将沉淀物在步骤2)中形成的化合物(III)进行过滤以分离出化合物(III),然后用碱处理化合物(III)以释放
倍他司汀l-薄荷酸薄荷酯化合物(IV),最后在碱的存在下
水解化合物(IV)。这种创新的方法可以提供具有99.5%以上高光学纯度且高收率的
倍他司汀,因此在
抗组胺药物和抗过敏药物的开发中非常有用。