706753-75-5Relevant articles and documents
Preparation method of epinastine impurity A
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Paragraph 0036-0052, (2021/04/17)
The invention belongs to the technical field of medicines, and particularly relates to a preparation method of an epinastine impurity A. The invention provides a preparation method of an epinastine impurity A. The preparation method comprises the following steps: step 1, mixing epinastine free alkali, a hydrogenation catalyst and a reaction solvent, and carrying out heating reaction to prepare a reactant 1; step 2, filtering the reactant 1, removing the hydrogenation catalyst, and concentrating to obtain a reactant 2; and step 3, mixing the reactant 2 with a pulping solvent, pulping, filtering and drying to obtain an epinastine impurity A. The epinastine free alkali has a structure as shown in a formula I. The invention provides a preparation method of an epinastine impurity A. The technical defects of low purity and low yield of the prepared epinastine impurity A caused by many side reactions or low reaction conversion rate of an existing preparation method of the epinastine impurity A can be effectively overcome.
A facile synthesis of epinastine HCl via dehydroepinastine intermediate
Park, Sang Won,Kang, Han Eol,Yun, Wheesahng,Lee, Sang Yeul,Nam, Tae-gyu
supporting information, (2019/12/24)
Epinastine is a second generation histamine H1 receptor antagonist used as a non-sedative antiallergic drug. When given orally, epinastine poorly penetrates blood-brain barrier (BBB) and appears to be free of cardiac toxicity as compared to other antihistamine drugs. A couple of synthetic approaches for epinastine HCl have been reported so far. They hold several problems such as explosive, highly toxic or expensive reagents. Moreover, they usually do not offer concise synthetic steps. In our synthesis shown here, a commonly used starting material, 6-(chloromethyl)-11H-dibenzo[b,e]azepine is treated with cyanamide to afford dehydroepinastine (14) in significantly high yield, which is subsequently reduced in the presence of aqueous HCl to give epinastine HCl in only two steps (75% overall yield for two steps). The problems associated with the reported processes such as using toxic and dangerous chemicals, lengthy synthetic steps or low overall product yields can be overcome by utilizing this new route. We believe our synthetic scheme might provide a breakthrough to reduce the cost of the production of epinastine HCl.
