Preparation method of hindered phenol antioxidant 1019

[0018] Dissolve 100g of 3,5-acyl chloride in 500mL of n-hexane, and gradually add the configured n-hexane solution of 3,5-acyl chloride into a solution containing 12.0g of propylenediamine, 20.0g of sodium hydroxide and 200mL of water under stirring In the mixed solution, the temperature of the reaction system was controlled to be 40° C. during the addition, and then the reaction was continued at 40° C. for 2 hours to the end of the reaction. After the reaction was completed, the temperature was raised to 60°C, the lower aqueous phase was separated, and the organic phase was washed with water for 2 to 3 times until the pH of the washing water was 6 to 7, then cooled to crystallize, filtered, and then dried to obtain the target product N,N'-bis (3-(3,5-Di-tert-butyl-4-hydroxyphenyl)propionyl)propionyl)diamine 94.3g, yield 97.9% (calculated as propylenediamine), HPLC content 99.2%.

[0020] Dissolve 100g of 3,5-acyl chloride in 400mL of cyclohexane, and gradually add the configured cyclohexane solution of 3,5-acyl chloride to 10.0g of propylenediamine, 17.8g of sodium carbonate and 100mL of water under stirring In the mixed solution, the temperature of the reaction system was controlled to be 50° C. during the addition, and then the reaction was continued at 50° C. for 1 hour to the end of the reaction. After the reaction was completed, the temperature was raised to 60°C, the lower aqueous phase was separated, and the organic phase was washed with water for 2 to 3 times until the pH of the washing water was 6 to 7, then cooled to crystallize, filtered, and then dried to obtain the target product N,N'-bis (3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)propionyl)diamine 77.8g, yield 96.9% (calculated as propylenediamine), HPLC content 98.9%.

[0022] Dissolve 100g of 3,5-acyl chloride in 300mL of methylcyclohexane, and gradually add the prepared 3,5-acyl chloride in methylcyclohexane to the solution containing 12.0g of propylenediamine, 48.6g of potassium carbonate and 500mL of water, the temperature of the reaction system was controlled to be 40°C when adding, and then the reaction was continued at 40°C for 2 hours to the end of the reaction. After the reaction was completed, the temperature was raised to 60°C, the lower aqueous phase was separated, and the organic phase was washed with water for 2 to 3 times until the pH of the washing water was 6 to 7, then cooled to crystallize, filtered, and then dried to obtain the target product N,N'-bis (3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)propionyl)diamine 95.0g, yield 98.7% (calculated as propylenediamine), HPLC content 99.0%.