- Preparation method of orthographic optimizing betahistine hydrochloride
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The invention discloses a preparation method of orthographic optimizing betahistine hydrochloride, and relates to the field of drug preparation. The preparation method includes the steps: adding raw materials into a reaction bottle according to the feeding ratio (molar ratio) of 2-methylpyridine to paraformaldehyde of 1:0.57, leading in nitrogen, stirring mixture for 20 hours at the temperature of125 DEG C and at 4 barometric pressure, performing reduced pressure distillation, and collecting distillation cut at the temperature of 130-145 DEG C and under the pressure of 16mm mercury columns toobtain light-yellow oily 2-hydroxyethyl pyridine; adding the 2-hydroxyethyl pyridine into a three-opening bottle, adding sodium hydroxide according to the feeding ratio of 2-(2-Hydroxyethyl)pyridineto sodium hydroxide of 1:0.05, heating the mixture to reach 95-100 DEG C, stirring the mixture for 2 hours, removing a water layer, performing reduced pressure distillation on an oil layer, and collecting the distillation cut at the temperature of 65-70 DEG C and under the pressure of 17mm mercury columns to obtain 2-vinylpyridine. The preparation method is simple in technological process, safe tooperate and mild in reaction, production efficiency and product quality can be greatly improved, and production cost is reduced.
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- Aza-Michael-type addition reaction catalysed by a supported ionic liquid phase incorporating an anionic heteropoly acid
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In this work, we have obtained substituted amines under mild conditions in good yields using the Aza-Michael-type addition of various amines to vinyl compounds catalysed by a supported ionic liquid incorporating an anionic heteropoly acid. Different catalysts, including Lewis acids, Br?nsted acids and heteropoly acids were investigated in which heteropoly acids having dual Br?nsted and Lewis acid characteristics were excellent catalysts. The ionic liquid incorporating a polytungstate anion supported on magnetic diatomaceous earth as a magnetically separable heterogeneous catalyst offered the best results in terms of yield. The solid nanocatalyst was easily removed with a magnet.
- Ghasemi, Mohammad Hadi,Kowsari, Elaheh,Shafiee, Abbas
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supporting information
p. 1150 - 1153
(2016/03/09)
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