A synthesis process of anti-dandruff hydroxy pyridone

Abstract

The present application relates to the technical field of organic synthesis, in particular to a synthesis process of piroctone olamine for dandruff removal. The process comprises: in a mixed solvent of ethyl lactate, propylene carbonate and water, 4-methyl-6-(2,4,4-trimethylpentyl)-2H-pyran-2-one is reacted with aqueous hydroxylamine in the presence of immobilized bifunctional phase transfer catalytic resin and potassium carbonate, hydroxylamine is added by A and B two parts of staged temperature control, and pH is accurately adjusted to 7-8; after reaction, the catalyst and impurities are separated by grading filtration, the filtrate is purified by seed-induced crystallization and activated carbon decolorization recrystallization. The product of the process has a purity of more than 99%, the related substances are less than 0.5%, the platinum-cobalt color is less than 20 Hazen, the crystal particle size is uniform, the suspension stability in shampoo is good, and the catalyst can be recycled and is environmentally friendly.

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