- Synthesis method of high-purity histamine dihydrochloride
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The invention discloses a synthesis method of high-purity histamine dihydrochloride, and belongs to the technical field of organic synthesis. The method comprises the steps: in a solvent A, carrying out a decarboxylation reactionon L-histidine at the temperature of 110-150 DEG C under the effect of a composite decarboxylation catalyst, and carrying out filtering after the reaction is completed, wherein the composite decarboxylation catalyst is composed of a main catalyst and an auxiliary catalyst, the main catalyst is selected from sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, pyridine, 4-methylpyridine, aniline, 4-methylaniline, ,N,N-dimethylaniline and N, N-dimethylformamide, and the auxiliary catalyst is one selected from benzophenone, acetophenone, benzophenone and p-methyl acetophenone; carrying out reduced pressure distillation on a filtrate, adding water into residues, and adjusting the pH value to 5-6 by using hydrochloric acid to obtain an aqueous solution; extracting the aqueous solution at least once by using an extracting agent to remove impurities; and evaporating to remove water in the aqueous solution, pulping with a solvent B, filtering and drying to obtain the product.
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Paragraph 0032-0046
(2021/01/28)
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- CONTINUOUS PROCESS FOR THE PREPARATION OF 2-(1H-IMIDAZOL-4-YL) ETHANAMINE AND PHARMACEUTICALLY ACCEPTABLE SALTS THEREOF
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of the invention The invention relates to a commercially viable, cost effective and energy efficient process for the preparation of 2-(1H-Imidazol-4-yl) ethanamine or pharmaceutically acceptable salts thereof in high purity and yield via application of continuous flow technology.
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Page/Page column 6
(2019/01/21)
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- Synthetic method of histamine dichloride
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The invention discloses a synthetic method of histamine dichloride, and belongs to the field of drug synthesis. The synthetic method comprises the following steps: preparing a cyano methylimidazole intermediate through oxidization of TCCA (Trichloroisocyanuric Acid) under an alkaline condition by taking L-histidine as an original raw material, and then preparing medicinal histamine dichloride through catalytic hydrogenation and one-step salifying process. In the histamine dichloride compounded through the synthetic method, the content of related substances is less than 0.5 percent, the content of a single impurity is less than 0.1 percent, and the histamine dichloride accords with medicinal level. A reagent adopted by the technology is cheap and of low-toxicity, the reaction is safe and reliable, an alcohol solvent can be recycled, after-treatment operation is simple and convenient, and the technology is environment-friendly and is beneficial for large-scale industrial production.
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Paragraph 0008; 0014; 0015
(2017/03/24)
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