Synthesis method of highly hindered phenol antioxidant 1010

The invention relates to a synthesis method of a highly hindered phenol antioxidant 1010, which comprises the following steps: adding beta-(3, 5-di-tert-butyl-4-hydroxyphenyl) methyl lactone, pentaerythritol and a basic ionic liquid into a reaction kettle, adjusting the reaction pressure in the reaction kettle to 0.1-0.1 MPa and the reaction temperature to 170-190 DEG C, and reacting for a period of time to obtain a reaction solution; cooling the obtained reaction liquid to a certain temperature, adding an organic solvent into the reaction liquid, and standing for layering to obtain an upper layer which is an organic solvent phase and a lower layer which is an alkaline ionic liquid phase; and recrystallizing the organic solvent phase to obtain the antioxidant 1010. According to the method, the ester exchange reaction is carried out by taking the beta-(3, 5-di-tert-butyl-4-hydroxyphenyl) methyl lactonate and the pentaerythritol as raw materials and taking the basic ionic liquid as a catalyst, the basic ionic l