A synthetic method of Avobenzone Supergoop, comprising the following steps:
1), the alkylation reaction takes toluene and chloro-tert-butane as raw materials, and uses aluminum trichloride as a catalyst, the reaction temperature is 23.5 ° C, and the reaction time is 85min to obtain p-tert-butyltoluene; The molar ratio of butane to toluene is 1:1.6;
2), in the oxidation reaction, potassium permanganate is used as an oxidizing agent, and the p-tert-butyltoluene obtained in step 1) is oxidized into p-tert-butylbenzoic acid; the reaction temperature is 85 ° C, the reaction time is 8.5h, and p-tert-butyl The molar ratio of toluene and potassium permanganate is 1:3, and the potassium permanganate oxidant is added in 5 to 8 times. Preferably, 3 mole parts of potassium permanganate oxidant is put into the reaction system in 6 times, the first time is 0.9 mole part, the second time is 0.6 mole part, and the third and fourth time are 0.5 mole part, 0.3 molar part was put in for the last time, and 0.2 molar part was put in for the last time, the final yield was 83.1%, and the purity was 98.6%.
3), in the esterification reaction, take p-tert-butyl benzoic acid and methanol as raw materials, and react in two stages; the first stage p-tert-butyl benzoic acid and methanol mol ratio are 1: 3.5, and the reaction time is 3h, and the reaction After the end of the distillation, water and methanol were separated; in the second stage, 3.5 moles of methanol was added, and the reaction time was 5h; after the reaction was completed, the water and methanol were separated by distillation; The molar ratio of benzoic acid and methanol was 1:7, and the reaction was refluxed for 8h.
4), the acylation reaction takes phenethyl ether and acetic anhydride as raw materials, with phosphotungstic acid as a catalyst, the mol ratio of anisole and acetic anhydride is 1: 1.5, the reaction time is 4h, and the reaction temperature is 115 ℃;
5), in the condensation reaction, take methyl para-tert-butyl benzoate and p-methoxyacetophenone as raw material, take sodium amide as catalyzer, dimethylbenzene is solvent, p-methoxyacetophenone and p-tert-butylbenzene The molar ratio of methyl formate is 1:1.4, the reaction temperature is 100°C, and the reaction time is 5h, and finally Avobenzone Supergoop is obtained. The preferred reaction temperature is 95°C, and the molar ratio of p-methoxyacetophenone to methyl p-tert-butylbenzoate is 1:1.4.