New Process for Synthesis of Antioxidant 626

The antioxidant 626 [Bis(2,4-di-tert-butylphenyl)Pentaerythritol Diphosphite] was synthesized through a two step reaction.First 2,4-di-tert-butylphenol was added to phosphorus trichloride and toluene with tetrabutylammonium bromide as catalyst to synthesis intermediate,then the intermediate reacted with pentaerythriol to synthesis antioxidant 626.The effects of catalysts,reaction solvents,the molar ratio of raw materials,reaction temperature,reaction time and solvents for crystallization on the yield of product were explored.Results of the experiments revealed when the molar ratio of 2,4-di-tert-butylphenole,phosphorus trichloride and pentaerythritol was 2.0:2.16:1.0,the average yield for the antioxidant 626 was 88.1%.The quality of product conforms to the standards.