32509-69-6Relevant academic research and scientific papers
Preparation method of hindered phenol antioxidant and intermediate thereof
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Paragraph 0051-0066, (2020/10/04)
The invention provides a preparation method of a hindered phenol antioxidant and an intermediate thereof. The preparation method comprises the following steps of: carrying out Friedel-Crafts reactionon a compound a and a compound b under the action of a main catalyst organic sulfonic acid and/or trifluoroacetic acid and a cocatalyst to obtain a hindered phenol antioxidant intermediate shown as aformula I; wherein the structural formulas of the compound a, the compound b and formula I are shown as the specification, wherein R1 is selected from H and substituted or unsubstituted alkyl of C1-C4, and R2 is selected from substituted or unsubstituted alkyl of C1-C4. According to the preparation of the hindered phenol antioxidant intermediate, the organic sulfonic acid and/or trifluoroacetic acid are/is adopted to replace a hydrogen chloride gas catalyst, so that the reaction safety is greatly improved, the requirements on equipment are reduced, and the equipment cost is also reduced.
Process for the preparation a bis(3,3-bis(4-hydroxyalkylphenyl)butanoic acid)diol ester
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, (2008/06/13)
By dividing the known condensation of acetoacetic acid diol esters with phenols into two process steps, a reduction in the cost of the entire process can be achieved. Methyl acetoacetate is first condensed with a phenol and the methyl 3,3-bis(4-hydroxyalkylphenyl)butanoate formed is reacted with the desired diol in the presence of a transesterification catalyst. In this way only one acetoacetic ester is necessary for various final products. The final products are useful stabilizers for plastics, in particular polyolefins.
