The invention discloses a synthetic method for a kind of polysubstituted
baicalein derivatives shown as a formula I, and in the formula I, R1, R2 and R3 are H, hydroxyl,
alkyl, alkoxy and the like. By modifying
baicalein B-ring skeleton, the
baicalein derivatives are synthesized, which are substantially improved in dissolvability, anticancer activity and other aspects compared with baicalein. The method employs substituted
benzaldehyde and 3,4,5-trimethoxyphenol as basic raw materials, and the B-ring polysubstituted baicalein derivatives are prepared through 3 steps. The method concretely comprises performing
condensation reaction on the substituted
benzaldehyde and an
acid anhydride under the effect of an alkali catalyst, so as to obtain substituted
cinnamic acid, and further synthesizing substituted
cinnamoyl chloride, performing
acylation reaction on the substituted
cinnamoyl chloride and 3,4,5-trimethoxyphenolunder the effect of a catalyst, so as to obtain a
chalcone compound, and performing cyclization reaction on the
chalcone compound under the effect of a catalyst, so as to obtain the corresponding polysubstituted baicalein derivative. The method is simple in technology, abundant in raw materials, high in yield, good in product purity and low in cost, and has wide application prospect.