Organic base catalyst for synthesizing aryl carboxylate through ester exchange

Abstract

The invention relates to an organic base catalyst for synthesizing aryl carboxylate through ester exchange, belonging to the technical field of organic chemistry and catalytic chemistry. In a process of synthesizing aryl carboxylate through ester exchange, phenyl methyl oxalate and phenyloxalate are synthesized by using phenol and dimethyl oxalate as raw materials through ester exchange. The organic base catalyst is an organic compound containing nitrogen, phosphorus and halogen elements and immobilized organic base thereof; and hydroxyl on the surface of an immobilized heterogeneous catalyst is subjected to treatment of silane reagents with different polarities to obtain a catalyst with different surface polarities. The catalyst has good catalysis property, is easy to separate from a reaction system, is mild in ester exchange condition, convenient for continuation, and is suitable for industrialized application, wherein the transfer rate of the dimethyl oxalate can reach above 90 percent and the selectivity of the phenyloxalate can reach above 70 percent.

Description

[0001] The patent application for the present invention is a divisional application. The invention title of the original application is "organic acid-base catalyst for the synthesis of aryl carboxylate by transesterification", the filing date is January 2, 2008, and the application number is 200810050203.6. technical field [0002] The invention belongs to the technical field of organic chemistry and catalytic chemistry, and relates to a class of organic acid-base catalysts for synthesizing monoaryl carboxylate and diaryl carboxylate by transesterification of dialkyl carboxylate and monoaryl hydroxyl compound. Background technique [0003] Diaryl carbonate is an important organic carbonate with low toxicity and no pollution. It can be used to synthesize many important organic compounds and polymer materials. ) reaction, non-phosgene transesterification polycondensation into high-quality polycarbonate, which has high economic value. The synthesis methods of diaryl carbonate ...

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Problems solved by technology

[0004] In the transesterification method, phenol and dimethyl carbonate transesterification reaction synthesis diphenyl carbonate method researches more, as JP323654, US5426207, DE2528142, patents such as CN1803282 (200610020205.1) have been reported, the raw material dimethyl carbonate used in this method Cheap and easy to obtain, the problem of this process is that methanol and dimethyl carbonate form an azeotrope, which increases the difficulty of separation of raw materials and products; the reaction rate is too slow, and the production operation cycle is too long

In the above-mentioned patents, when dimethyl oxalate is used as a raw material to prepare the raw material for synthesizing diphenyl carbonate, that is, methyl phenyl oxalate or diphenyl oxalate, the catalysts used include supported titanium dioxide and composite titanium dioxide. Silicon oxide, supported molybdenum trioxide, supported Mo-Sn double metal oxide, etc., these catalysts are all weak Lewis acid catalysts. When reacting in a batch reactor, the activity of the catalyst and the main product diphenyl oxalate The selectivity is not high, especially the selectivity of diphenyl oxalate is less than 47.5%, and the active center metal ion in the heterogeneous catalyst is easy to lose in the reaction mass in the transesterification reaction

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