The invention discloses a synthesis method of an
antioxidant GM, which comprises the following steps: (1) under the protection of
nitrogen, mixing 2-tert-butyl-4-methylphenol and a functionalized acidic
ionic liquid, stirring and heating, dropwise adding acrylic anhydride, carrying out heat preservation reaction after dropwise adding, filtering, separating and washing to obtain 2-
acrylic acid-2-tert-butyl-4-methylphenyl ester; and (2) under the protection of
nitrogen, mixing 2-
acrylic acid-2-tert-butyl-4-methyl phenyl ester,
dimethoxymethane, 2-tert-butyl-4-methylphenol, the functionalized acidic
ionic liquid, the supported phosphotungstic
heteropoly acid and
methanol, stirring, heating, carrying out
reflux reaction, filtering, separating, washing, carrying out reduced pressure
distillation, filtering, separating and washing while the mixture is hot, thereby obtaining the
antioxidant GM. The functional acidic
ionic liquid and the supported phosphotungstic
heteropoly acid are adopted, so that the target
antioxidant GM with higher purity and yield can be obtained, and better green and environment-friendly development is realized.