2.2 The synthesis of NF-κB inhibitors
The classic synthesis method of chalcone derivatives is to condense substituted acetophenone and substituted benzaldehyde in alkaline alcohol solution. Because the phenolic hydroxyl group is easy to be oxidized, especially under alkaline conditions. The reaction yield of hydroxychalcone is very low in the classical synthesis of hydroxychalcone. So we explored a method of preparing hydroxychalcone by direct condensation reaction under the catalysis of thionyl chloride. Using thionyl chloride as a catalyst and ethanol as a solvent, hydroxyacetophenone and hydroxybenzaldehyde are condensed at room temperature for 24 hours to obtain various hydroxychalcone derivatives. The detail information is showed in the supplementary information.