The invention discloses a semi-synthesis method of phenolic hydroxyl
flavonoid compounds and an
iodine recycling method, relating to two ways A and B and
iodine recycling, wherein in the way A, flavone is easily dissolved in a
pyridine solvent of
ethylene glycol or glycerin, and with
iodine as a dehydrogenating agent, flavone is generated by heating and
dehydration; in the way B,
flavanone or flavone is not dissolved in
pyridine of
alcohol, the complexing of trivalent aluminum and
flavanone is adopted, the
solubility of the complexing and
dehydrogenation products is high in
alcohol, flavone is separated from the
aluminum complex by use of
phosphoric acid and the like, and flavone insoluble in water is separated out and obtained by filtering. The method disclosed by the invention is a universal method for preparing
flavonoid compounds through
dehydrogenation of phenolic hydroxyl dihydro flavonoids, the dosage of the reagents such as
pyridine and the like is very small, and the treatment is simple, so that the method is suitable for industrial production. Take the
diosmin preparation using
hesperidin as an example, compared with the existing documents and patents, in the method disclosed by the invention, the dosage of organic solvents such as pyridine and the like is the least, the treatment is the simplest, the yield is the highest, and the method is environment-friendly (iodides can be oxidized by
hydrogen peroxide, the recycling process is simple, and the yield is relatively high), and industrial production is easy to realize.