Method for preparing 2,5-dialkoxy terephthalic acid

The invention belongs to the technical field of organic synthesis and relates to ortho-position and para-position substitutions of an aromatic ring, in particular to a synthetic technique of alkoxy ortho-position and para-position substituted dicarboxylic acid. According to the preparation method of 2,5-dialkoxy terephthalic acid, provided by the invention, the 2,5-dialkoxy terephthalic acid is prepared from 1,4-dihalogenated-2,5-dialkoxy benzene by adopting a Grignard reaction mechanism through the following processes: preparation of a Grignard reagent, carbon chain propagation, hydrolysis, separation and purification, and the like; the preparation method provided by the invention can be proceeded at normal pressure and has the advantages of stable reaction, short period, convenience for operating and easiness of being controlled; and the product has high yield and high purity.