Method for preparing 2, 2 '-dihydroxy-3, 3', 5, 5 '-tetra-tert-butylbiphenyl by using microchannel reactor

Abstract

The invention relates to a method for preparing 2, 4-difluorobenzene by using a The invention discloses a method for preparing 2, 2 '-dihydroxy-3, 3', 5, 5 '-tetra-tert-butylbiphenyl, which comprises the following steps: preparing a mixed solution from 2, 4-di-tert-butylphenol and alkali liquor according to a certain proportion, respectively pumping the mixed solution and a hydrogen peroxide solution into a micro-channel reactor, fully mixing, reacting the mixed material in a first reaction area module of the micro-channel reactor, mixing with toluene in a mixing area module, and reacting at the temperature of 80-90 DEG C to obtain the 2, 2'-dihydroxy-3, 3 ', 5, 5'-tetra-tert- The method comprises the following steps: adding a toluene solution into a first reaction area module, carrying out a neutralization reaction on the toluene solution and an acid solution in a second reaction area module, carrying out continuous phase separation on the obtained product solution to obtain a toluene solution D containing 2, 2 '-dihydroxy-3, 3', 5, 5 '-tetra-tert-butylbiphenyl, and carrying out concentration, crystallization and washing to obtain the target product 2, 2'-dihydroxy-3, 3 ', 5, 5'-tetra-tert-butylbiphenyl. By utilizing the method, the reaction efficiency can be obviously improved, the reaction time is greatly shortened, the possible explosion risk is avoided, the production process is more convenient to control, the production cost is reduced, and the defects of high labor intensity, long production period, low product quality and the like in the traditional production are overcome.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a method for preparing 2,2'-dihydroxy-3,3',5,5'-tetra-tert-butylbiphenyl by using a microchannel reactor. Background technique [0002] 2,2'-Dihydroxy-3,3',5,5'-tetra-tert-butylbiphenyl is an important raw material for the synthesis of bidentate phosphine ligands in carbonyl hydroformylation. At present, it is mainly prepared by oxidative coupling in industry. get. [0003] Its synthesis method is mainly divided into alkali-catalyzed reaction using hydrogen peroxide according to the different oxidants used. US Patent US4380676 discloses a kind of 2,2'-dihydroxy-3,3',5,5'-tetra-tert-butylbiphenyl. The synthesis method adopts alkali catalysis and hydrogen peroxide as an oxidant, and is characterized in that the hydrogen peroxide is slowly added dropwise at a high temperature (80° C.) to control the reaction speed and ensure the safety of the reaction, so it i...

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Problems solved by technology

[0003] The synthesis method is mainly divided into base-catalyzed reaction using hydrogen peroxide according to the different oxidizing agents used. US Patent No. 4,380,676 discloses a 2,2'-dihydroxy-3,3',5,5'-tetra-tert-butylbiphenyl The synthetic method adopts alkali catalysis and hydrogen peroxide as an oxidant, and is characterized in that hydrogen peroxide is slowly added dropwise at high temperature (80° C.) to control the reaction speed and ensure the safety of the reaction. Therefore, it is dangerous and unfavorable for scale-up production; The intermittent reaction needs to be supplemented more, and the efficiency is low

[0004] Using air or oxygen as the oxidant requires transition metals (copper or cobalt complexes (CN201911011611.5)) as catalysts, and sometimes organics as solvents, which will not only cause subsequent separation difficulties, but also reduce the oxidation reaction in order to prevent explosions. rate

[0005] The preparation methods reported so far all use a batch reaction method, and the reaction process needs to be completed in multiple steps. Therefore, it is necessary to develop an efficient and safe synthetic method to improve the 2,2'-dihydroxy-3,3',5,5'- Production efficiency of tetra-tert-butylbiphenyl

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