Olmesartan medoxomil of high purity (99.3-99.7% by HPLC ) is prepared using an improved process of its intermediate, namely- ethyl-4-(1-hydroxy-1-methylethyl)-2-propyl-1-[[2'-(2-(triphenylmethyl)-2H-tetrazol-5yl]biphenyl-4-yl]methyl]imidazole-5-carboxylate, comprising:
Reacting ethyl-4-(1-hydroxy-1-methylethyl)-2-propylimidazole-5-carboxylate with N-(Triphenylmethyl)-5-[4'-(bromomethyl)biphenyl-2- yl]tetrazole in an organic solvent in presence of a base and a phase transfer catalyst in non-aqueous system to give after workup, ethyl-4-(1-hydroxy-1-methylethyl)-2-propyl-1-[[2'-[2-(triphenylmethyl)-2H-tetrazol-5yl]biphenyl-4-yl]methyl]imidazole-5-carboxylate, which is further processed, by following improved reaction conditions in three steps to provide substantially pure [HPLC purity 99.3 to 99.7 %] olmesartan medoxomil.
A further process relates to the purification of olmesartan medoxomil by treatment with isopropyl alcohol and methyl ethyl ketone.
高纯度
奥美沙坦酯(HPLC检测为99.3-99.7%)是通过改进的中间体工艺制备的,即乙基-4-(1-羟基-1-甲基乙基)-2-丙基-1-[[2'-(2-(三苯甲基)-2H-
四唑-5基]
联苯-4-基]甲基]咪
唑-5-羧酸乙酯,包括:
在有机溶剂中,在非
水体系中,在碱和相转移催化剂的存在下,将乙基-4-(1-羟基-1-甲基乙基)-2-丙基咪
唑-5-羧酸乙酯与N-(三苯甲基)-5-[4'-(
溴甲基)
联苯-2-基]
四唑反应,经过处理后得到乙基-4-(1-羟基-1-甲基乙基)-2-丙基-1-[[2'-[2-(三苯甲基)-2H-
四唑-5基]
联苯-4-基]甲基]咪
唑-5-羧酸乙酯,然后按照改进的反应条件进行三步处理,以提供高纯度[HPLC纯度99.3至99.7%]的
奥美沙坦酯。
另一种工艺涉及通过
异丙醇和
甲乙酮处理来纯化
奥美沙坦酯。