Application of Br phi nsted acid ion liquid to preparation of diphenyl oxalate

Abstract

The invention discloses an application of a Bronsted acid ion liquid to preparation of diphenyl oxalate. Phenol and dimethyl oxalate are subjected to transesterification under the catalytic action of the Bronsted acid ion liquid, and the transesterification is carried out under a solvent-free condition, so that a mixture with diphenyl oxalate is obtained, wherein the reaction temperature ranges from 150 DEG C to 250 DEG C, the reaction time ranges from 2h to 5h, the mole ratio of phenol to diphenyl oxalate is (2.0-10.0):1, and the mole ratio of the Bronsted acid ion liquid as a catalyst to dimethyl oxalate as a substrate is 5-20%. By using the method, diphenyl oxalate (namely the mixture with diphenyl oxalate is obtained) can be greenly and safely prepared through the transesterification between phenol and dimethyl oxalate under mild reaction conditions and at high yield and low cost.

Description

technical field [0001] The present invention relates to a kind of organic synthesis method, especially Application of acid ionic liquid in the preparation of diphenyl oxalate (DPO). Background technique [0002] Diphenyl carbonate (DPC) is an important organic carbonate with low toxicity and no pollution. It can be used to synthesize polycarbonate, methyl p-hydroxybenzoate, monoisocyanate, etc. It is widely used in plastic industry, synthetic pesticide, medicine, etc. field. [0003] Diphenyl oxalate (DPO) can be decarbonylated to obtain diphenyl carbonate, which has a mature process. [0004] At present, there are three main synthesis methods of DPC: [0005] 1) Phosgene method, first react phosgene and phenol in NaOH to generate phenyl chloroformate, and then react with phenol to synthesize DPC (S-1); [0006] 2) transesterification method, including phenol and dimethyl carbonate (DMC) transesterification method (S-2), phenol and dimethyl oxalate (DMO) transesterifica...

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Problems solved by technology

[0011] The synthesis of DPC by the transesterification of phenol and DMO generally uses a homogeneous catalytic system such as Lewis acid or organic compounds containing titanium and tin, which has defects such as short life, difficult separation and recovery, and severe equipment corrosion, which is not conducive to industrial production.

Although heterogeneous catalysts can partially overcome many disadvantages of homogeneous catalysts and simplify the separation process, the preparation process of such catalysts is complicated, and it is still difficult to meet the requirements of industrialization in terms of stability and activity.

[0012] According to literature reports, existing heterogeneous catalysts include modified MCM-41 molecular sieves (References: Liu, Y.; Zhao, G.; Zhu, W.; Wang, J.; Liu, G.; Zhang, W. .;Jia, M. Journal Of The Brazilian Chemical Society 2010, 21, 2254-2261.), MoO 3 / SiO 2 (Reference: Gong Jinlong. Loaded MoO 3 Catalytic transesterification of dimethyl oxalate and phenol to synthesize diphenyl oxalate [D]. Tianjin University, 2004.), TiO 2 / SiO 2 (Reference: Wang Shengping. Synthesis of diphenyl carbonate by transesterification of phenol and dimethyl oxalate [D]. Tianjin University, 2003.), etc., both have low conversion rate of dimethyl carbonate and low yield of diphenyl carbonate And other issues

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