Preparation method of terephthalic acid and 4-methyl-3-cyclohexene-1-carboxylate

A kind of preparation method of terephthalic acid includes steps: under the catalysis of aluminum chloride, isoprene and methyl acrylate are subjected to a Diels-Alder reaction to produce a crude product. The Diels-Alder reaction is performed in the absence of solvent and at a temperature of -20 to 50℃; the crude product is distilled under reduced pressure to obtain a precursor, and the precursor is sequentially reacted through the dehydrogenation, hydrolysis and oxidation to produce terephthalic acid. The preparation method can effectively save the use of organic solvents and thermal energy to reduce any harm to the environment and energy consumption, and can quickly produce a crude product in high yield with a high selective syndiotactic substance.