Method for preparing fluoro-compound by microwave halogen-exchange fluorination

Abstract

The invention discloses a method for preparing fluoro-compound by microwave halogen-exchange fluorination. The method comprises the following steps: a fluridizer is put into microwave to be dried for standby use; a reactant, the fluridizer, a solvent and a catalyst are added into a reactor; the reactor is sealed, and nitrogen is filled into the reactor for pressurizing, microwave heating and stirring are carried out to ensure full reaction; when the reaction is over, the temperature is cooled to room temperature, and the material is filtered to obtain the fluoro-compound crude product. The invention adopts a microwave generator to radiantly heat in the reactor, which replaces the traditional heating method at the exterior of the reactor, thus being beneficial for improving efficiency; the invention adopts the sealing method to prevent air from oxidizing, thus reducing the high temperature coking of the product; the invention increases the pressure of nitrogen in the reaction, thus being capable of accelerating the reaction speed; the invention adopts filtering to recover the by-product, rectified liquid phase transfer catalyst and the solvent are used indiscriminately in a recycling way and can be recycled by adding the reactant and the fluridizer, compared with a previous solid phase transfer catalyst which adopts the crystallization recovering method, no waste water is generated, and the cost is lowered simultaneously.

Description

technical field [0001] The invention belongs to the preparation technology of fluorine-containing compounds, in particular to a method for preparing fluorinated compounds by microwave halogen exchange fluorination. Background technique [0002] Fluorine-containing aromatic compounds are important raw materials and intermediates for the preparation of fluorine-containing physiologically active substances, and can be used in the synthesis of fluorine-containing pesticides and medicines. In addition, it can also be used as a raw material for the synthesis of fluorine-containing dyes and fluorine-containing resins. For example, fluorobenzaldehyde compounds, in medicine, can be used in the synthesis of various drugs such as antihypertensive drugs, anticancer drugs, muscle relaxants, etc., and have remarkable curative effects in the treatment of hypertension, diabetes, liver cirrhosis and other diseases; In the synthesis, the dyes synthesized with it as raw materials have excelle...

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Problems solved by technology

In some previous patent documents (Finger G C, Kruse C W. et al. Aromatic fluorine compounds VIII: Replacement of aromatic-Cl and-NO 2 groups by-F.J Am Chem Soc.1956, 78:6034-6037, US 4,642,398 10 Feb.1987), this method can only produce nitro, cyano, sulfonyl, trifluoromethyl, trichloro Preparation of fluorine-containing aromatics with strong electron groups such as methyl, but cannot produce aromatic rings containing weak electron-withdrawing groups such as aldehyde groups, alk(aromatic)acyl groups, etc.

Zheng Yong Liang (Zheng Yong Liang, Chun Xu Lü, Jun Luo, Li Bin Dong. A polymerimidazole salt as phase-transfer catalyst in halex fluorination irradiated by microwave. Journal of Fluorine Chemistry, 2007, 128: 608-611) adopt poly high The microwave reaction of molecular quaternary ammonium salts synthesizes fluorobenzaldehyde compounds. Although the yield is high, the catalyst cannot be recycled, and a large amount of inorganic waste is generated, which is difficult to handle.

Li Bindong (Li Bindong, Liang Zhengyong, Lu Chunxu. Microwave-catalyzed synthesis of fluorinated aromatic aldehydes (ketones) by tetraphenylphosphorus bromide. Fine Petrochemical Industry, 2007, 24(5): 25-28) using tetraphenylphosphorus bromide Synthesize fluorinated aromatic aldehydes with acetone, furan, and crown ether by microwave catalysis, but there are also many reaction wastes, serious environmental pollution, and more tar in the normal pressure reaction product, difficult post-processing, and high cost

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