1204245-29-3Relevant articles and documents
Preparation method of lipoic acid impurity A
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Paragraph 0029-0030; 0035-0036, (2021/08/11)
The invention relates to a preparation method of a lipoic acid impurity A, and belongs to the field of compound synthesis. The invention aims to overcome the defects of complex operation and harsh reaction conditions in the prior art, and provides the preparation method of the lipoic acid impurity A. The preparation method is mild in condition and high in product purity. The preparation method comprises the following steps: (1) dissolving lipoic acid in a reaction solvent, adding an oxidant for reaction, and removing solids and the solvent after the reaction is completed to obtain a compound B; (2) respectively adding the compound B, sodium thiosulfate and a catalyst into water, then adding hydrochloric acid, carrying out hydrolysis ring-opening reaction, and filtering after the reaction is completed to obtain a compound C; and (3) respectively adding the compound C, sodium sulfide and formaldehyde into the reaction solvent for reaction, extracting after the reaction is completed, drying, and purifying to obtain a compound D lipoic acid impurity A. The method is mild in condition, and the prepared lipoic acid impurity A is high in purity.
