Crystallization and activated carbon decolorization

Add sodium borohydride, the active carbon decoloration is preferably a weak acid system

If the reaction is not afraid of water, add a few drops of sodium sulfate solution!

First, you may have a color from oxidation. It is recommended that you pay attention to protection, isolated oxygen, see if there is no color.
In addition, the activated carbon is decoloring, if it is so cooked, it feels not appropriate because the activated carbon itself can be an oxidative surface catalyst, so you can try to isolate air, normal temperature or low temperature activated carbon try, mainly to seeIs there any effect.To remember, first look at the effect, if there is effect, on this, try to choose activated carbon

It may be that the solubility of colored substances in chlorobenzene is very good, change solvent decolorization

You can add appropriate amount of silica gel to add silica filtration (this is not column)