Abstract: The present disclosure provides a semi-synthetic method of dihydroquercetin, belonging to the field of synthesis of organic drugs. The semi-synthetic method includes the following steps: adding quercetin dihydrate to solvent water adjusted to be alkaline with an alkalizing reagent, heating and stirring to dissolve the mixture, and then adding thiourea dioxide under the protection of an inert gas to perform a reduction reaction, to obtain an endpoint reduction reaction solution; diluting the endpoint reduction reaction solution with water and cooling the resultant, and then acidizing, aging, and filtering the resultant to obtain a filtrate and a filter cake; extracting, washing, drying, concentrating, and repeatedly crystallizing the filtrate to obtain dihydroquercetin; and recycling the filter cake after being washed.

Abstract: The present disclosure provides a semi-synthetic method of dihydroquercetin, belonging to the field of synthesis of organic drugs. The semi-synthetic method includes the following steps: adding quercetin dihydrate to solvent water adjusted to be alkaline with an alkalizing reagent, heating and stirring to dissolve the mixture, and then adding thiourea dioxide under the protection of an inert gas to perform a reduction reaction, to obtain an endpoint reduction reaction solution; diluting the endpoint reduction reaction solution with water and cooling the resultant, and then acidizing, aging, and filtering the resultant to obtain a filtrate and a filter cake; extracting, washing, drying, concentrating, and repeatedly crystallizing the filtrate to obtain dihydroquercetin; and recycling the filter cake after being washed.