- A preparation method of the clonidine hydrochloride
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The invention discloses a method for preparing the clonidine hydrochloride, including intermediates 1 synthesis, intermediate 2 synthesis and clonidine hydrochloride synthetic three steps, the present invention in order to 2, 6 - dichloroaniline as raw materials, through the hydroformylation reaction get intermediate 1, "one-pot" get clonidine free base, finally with hydrogen chloride ethanol solution into salt clonidine hydrochloride. By processing the raw material synthetic process, by utilizing the free alkali in the course of refining into salt after adjusting pH, and the clonidine hydrochloride is used for purification of the pulping process control such as ethyl acetate, to obtain a high-purity clonidine hydrochloride preparation method. The method not only improves the product purity and yield, impurity can also effectively control, but also greatly reducing the cost, simplifying the process, is more suitable for industrial production.
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Paragraph 0050; 0057; 0058; 0063; 0064
(2018/04/28)
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- Imidazoline derivatives and the preparation thereof
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A process for the preparation of 2-(substituted aryl)amino-2-imidazoline derivatives by reacting appropriate substituted aniline derivatives with 1-aroyl-imidazoline-2-ones in the presence of at least two mols of phosphorus oxychloride per mol of the aniline derivative and optionally hydrolyzing the resulting intermediate compound. Certain novel 2-dihaloarylamino-2-imidazoline derivatives with hypotensive action are also disclosed.
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- Process for the manufacture of 2-arylamino-2-imidazoline derivatives and their salts
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A process for the preparation of the known and valuable 2-aryl-amino-2-imidazoline derivatives which comprises condensing an appropriately substituted aniline with a 1-acyl-imidazolidin-2-one to produce an intermediate compound which on neutralisation in an aqueous medium is converted into a N-acyl derivative of the 2-aryl-amino-2-imidazoline, and splitting the intermediate compound or the said N-acyl derivative to give the corresponding free arylamino-2-imidazoline derivative or a salt thereof.
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