- Synthetic method of epinastine hydrochloride
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The invention relates to a synthesis method of epinastine hydrochloride. The method comprises the following steps: reacting phthalic anhydride with aniline to obtain a compound 1, reacting the compound 1 with polyphosphoric acid under certain conditions to perform cyclization to obtain a compound 2, reducing carbonyl of the compound 2 under certain conditions to obtain a compound 3, and carrying out chlorination reaction on the compound 3 to obtain a compound 4, carrying out cyano substitution reaction on the compound 4 to obtain a compound 5, reducing the compound 5 by using a carbon-nitrogenunsaturated bond to obtain a compound 6, reacting the compound 6 with cyanogen bromide, and forming hydrochloride by using hydrochloric acid to obtain a compound 7; according to the method, the epinastine hydrochloride is prepared from bulk chemical products, is extremely low in price and mild in reaction condition, avoids the use of azide compounds, and the method is suitable for large-scale industrial production. The prepared epinastine hydrochloride is high in purity and low in cost, and has higher market competitiveness.
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- New tetracyclic guanidine derivatives with H1-antihistaminic properties. Chemistry of epinastine
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A series of new tetracyclic guanides were synthesized by various methods. Specific binding of the described compounds to histamine-1 and histamine-2 receptors was determined. The compound 3-amino-9, 13b-dihydro-1H-dibenz[c,f]imidazo[1,5-a]azepine (epinastine, WAL 801) combines high selectivity with high affinity for the H1 receptor and was selected from the compounds studied for further pharmacological and clinical investigations. Experimentally determined physicochemical parameters (pk(a)-value, partition coefficient) and the hydrogen-bonding ability of epinastine are indications that this compound will not easily cross the blood-brain barrier. This explains the absence of CNS side-effects of epinastine in pharmacological and clinical studies.
- Walther,Daniel,Bechtel,Brandt
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p. 440 - 446
(2007/10/02)
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