The invention relates to a method for preparing
aromatic acid through oxidation reaction of 1, 2, 3-grade
alkyl substituted aromatic compounds under iron
catalysis. The method comprises the following steps: under the action of an iron compound, providing proper temperature and / or
light energy, and in the presence of an oxidant and / or an additive, carrying out C-C bond breakage on benzyl positions of aromatic compounds in a
solvent to realize selective oxidation so as to obtain a corresponding oxidation compound
ketone or acid. According to the invention, C-C
bond rupture and oxidation are directly and selectively carried out on the benzyl position of the aromatic compound, so that the method has the advantages of simple reaction, simple operation, mild oxidation condition, high
atom economy, high reaction yield, easy separation and purification of the product, suitability for synthesis of
benzoic acid derivative compounds, and the like; air can be directly used as an
oxidizing agent, so that use of a large amount of heavy
metal salt is avoided, and the method is very attractive in industrial production; and the method has very large application potential in the fields of
metal catalysis,
chemical synthesis and the like by using cheap
metal for reaction.