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ChemicalBook CAS DataBase List Pyridoxamine dihydrochloride
524-36-7

Pyridoxamine dihydrochloride synthesis

5synthesis methods
The invention relates to a preparation method of pyridoxamine dihydrochloride, belonging to the technical field of the preparation of water soluble vitamins. The preparation method comprises the following steps: preparing pyridoxal oxime: taking pyridoxine hydrochloride as initial raw material and water as a reaction medium, adding activated manganese dioxide and concentrated sulfuric acid to generate pyridoxal by the reaction, and then reacting with anhydrous sodium acetate and hydroxylamine hydrochloride to obtain pyridoxal oxime; preparing pyridoxamine dihydrochloride: firstly enabling pyridoxal oxime to react with acetic acid and zinc to obtain acetic acid solution containing pyridoxamine, then decompressing the solution and reclaiming the acetic acid to obtain slurry concentrate, decompressing and reclaiming the acetic acid again to obtain pyridoxamine water solution, regulating the pH value to be alkaline so as to separate pyridoxamine out, adding water and hydrochloric acid after vacuum filteration, decoloring and filtering to obtain filtrate, decompressing and concentrating the filtrate until white solids are separated out, adding solvent and stirring, and finally crystallizing at the lower temperature, filtering and drying to obtain the pyridoxamine dihydrochloride. The invention has the advantages that the prepared pyridoxamine dihydrochloride has high total mol yield and purity, and the preparation method is reduced.
https://patents.google.com/patent/CN101628892A/en
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Yield:524-36-7 83%

Reaction Conditions:

with hydrogenchloride;hydrogen;5%-palladium/activated carbon in methanol;water at 20; under 760.051 Torr;

Steps:

6

Example 6; Production of 2-methyl-3-hydroxy-4-aminomethyl-5-hydroxymethyl-pyridine (pyridoxamine) dihydrochloride; 214 mg (1.04 mmol) of 2-methyl-3-hydroxy-4-cyano-5-acetyloxymethyl-pyridine were dissolved in 12 mol of methanol containing 300 μl of 30% hydrochloric acid at room temperature. 40 mg of 5 w/w% palladium on charcoal was added to the solution, and the mixture was hydrogenated under atmospheric pressure and at room temperature. The catalyst was then removed by filtration and the solvent of the filtrate removed under reduced pressure. The residue was recystallized from ethanol to afford 208 mg (0.86 mmol) of pyridoxamine dihydrochloride as an off-white solid; the amount obtained represented a 83% yield. The analytical data (1H and 13C NMR, LC, LC/MS and UV) obtained for the product confirmed through comparison of such data with those of a sample of commercially available pyridoxamine dihydrochloride that the product was the desired one.

References:

WO2006/66806,2006,A1 Location in patent:Page/Page column 16

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