Method for preparing p-fluoro anisole

A technology of p-fluoroanisole and fluoroanisole, which is applied in the field of preparation of high-purity p-fluoroanisole, can solve the problems that the reaction cannot be carried out, is not easy and economical, and cannot carry out condensation reaction, so as to ensure the production rate effect

Active Publication Date: 2011-08-10
宗铿
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] But when we tested according to the method disclosed in the above-mentioned patent documents, we found that sodium hydroxide (or potassium hydroxide), methyl alcohol, and p-bromofluorobenzene could not carry out the condensation reaction under the catalysis of copper oxide (or cuprous oxide) as reactants, and also That is, p-fluoroanisole cannot be obtained according to the technical scheme, and p-bromofluorobenzene is replaced by p-chlorofluorobenzene for testing, but the reaction still cannot be carried out
[0007] In addition, even if the reaction can be carried out according to the above-mentioned scheme, from the examples of the description of the document, it is also proposed that the conversion rate of the reactant into p-fluoroanisole is 90% to 99%, if the conversion rate of p-fluoroanisole Below 95%, then after the reaction finishes, unreacted p-bromofluorobenzene also needs to be separated from product p-fluoroani

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  • Method for preparing p-fluoro anisole
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  • Method for preparing p-fluoro anisole

Examples

Experimental program
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Effect test

Example

[0027] (Example 1)

[0028] The p-bromofluorobenzene in the raw materials used in this example was provided by Nanjing Fustar Chemical Co., Ltd., and the methanol solution of sodium methoxide was produced by Fengshui Social Welfare Chemical Plant, Zhangdian District, Zibo City, and its specification was 28 wt%.

[0029] The preparation method of p-fluoroanisole in this embodiment includes the following steps:

[0030] ①To generate p-fluoroanisole, add 500g (2.8mol) p-bromofluorobenzene and 260g solvent DMF in a 2000mL glass reaction flask equipped with a fractionation column with 4 theoretical plates, a mechanical stirring device and a thermometer. The chemical name is dimethylformamide, which is a transparent liquid), 750g of 28wt% methanol solution of sodium methoxide (the amount of sodium methoxide is 3.92mol) and 8g of powdery catalyst cuprous chloride, on the head of the fractionation column It is also equipped with a condenser, and cooling water is passed through the condenser...

Example

[0070] (Example 2)

[0071] The remaining steps of this embodiment are the same as those of embodiment 1, except that: in step ①, when p-bromofluorobenzene reacts with liquid sodium methoxide, the catalyst used is cuprous bromide, and the amount of cuprous bromide is 10g.

Example

[0072] (Example 3)

[0073] The rest of the steps in this embodiment are the same as in embodiment 1, except that: in step ①, when the reaction system is heated under stirring to generate p-fluoroanisole, the reaction mixture is first heated from room temperature within 1 hour (In this embodiment, it is 20°C) slowly rise to 65°C, and then proceed with other operations.

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Abstract

The invention discloses a method for preparing p-fluoro anisole, which comprises the following steps of: adding bromofluorobenzene, a solvent DMF (Dimethyl Formamide), liquid sodium methoxide and a catalyst into a reactor sequentially; heating the reaction system with stirring to perform the reaction of generating the p-fluoro anisole; performing the reaction for 10 to 15 hours continuously in the heating process; after completing the reaction, filtering a reaction mixture material to remove the catalyst; adding a liquid mixture material obtained after filtering into a distillation flask witha Nernst water separator, and then filling distilled water or water vapor into the distillation flask; heating the distillation flask to firstly evaporate out methanol, continuously heating the distillation flask until p-fluoro anisole and water are evaporated out in an azeotropic mode; with the continuous evaporation of p-fluoro anisole, collecting an organic phase at the lower layer of the Nernst water separator and ensuring a water phase to flow back into the distillation flask through the water separator; and feeding the organic phase collected from the Nernst water separator into a rectification device to be rectified so as to obtain a p-fluoro anisole finished product.

Description

technical field [0001] The invention relates to a preparation method of p-fluoroanisole, in particular to a preparation method for producing high-purity p-fluoroanisole. Background technique [0002] p-Fluoroanisole (p-Fluoroanisole, CAS: 459-60-9) is an important intermediate of medicine, pesticide and liquid crystal material, widely used; p-Fluoroanisole is a colorless to slightly yellow liquid, The boiling point is 157°C and the specific gravity is 1.114. [0003] At present, the production process of p-fluoroanisole has the following route: first react fluorobenzene with concentrated nitric acid to generate p-fluoronitrobenzene and m-fluoronitrobenzene, and then separate p-fluoronitrobenzene and m-fluoronitrobenzene to remove m-fluoronitrobenzene, reducing the obtained p-fluoronitrobenzene to obtain p-aminofluorobenzene, then adding sodium nitrite and p-aminofluorobenzene for diazotization reaction to form a diazonium compound, and then hydrolyzing the diazonium compoun...

Claims

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Application Information

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IPC IPC(8): C07C43/225C07C41/42
Inventor 宗铿
Owner 宗铿
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