1,4-Dihydroxybenzene
In the United States and China, the maximum allowable dosage of TBHQ in food is 200ppm,At present, the production of tert butyl hydroquinone both domestically and internationally adopts the tert butylation method of hydroquinone, as shown in Figure 2. According to different classifications of alkylation reagents.

Both domestic and foreign patent literature have reported this process, such as using toluene or xylene as solvents, the selectivity and yield of this reaction are relatively ideal. In addition, strong acidic ion exchange resins such as D001 and Amberlyst 35, solid acids [5], zeolites [6], and ionic liquids [7] can also be used as catalysts for this reaction, but their catalytic activity is not ideal.

Patent [10] discloses a method for preparing 2-tert butylhydroquinone and co producing BHA using isobutene as an alkylation reagent, which has good selectivity and high raw material utilization rate.

