A kind of preparation method of 3,4,5-trifluorobromobenzene compound

A technology of trifluorobromobenzene and trifluoroaniline, which is applied in the field of preparation of pesticides and pharmaceutical intermediates, can solve problems such as difficult separation of bromine, instability of diazonium liquid, and low reduction yield, so as to overcome difficult separation and recovery, and improve catalytic performance. Activity, beneficial to the effect of sedimentation growth

Active Publication Date: 2016-06-22
ZHEJIANG YONGTAI TECH CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

And after the 2,3,4-trifluoro-6-bromoaniline diazo is prepared and then reduced, the diazonium solution is extremely unstable, not only the reduction yield is low, but also there is a great safety hazard
In addition, the use of one equivalent of bromine leads to higher production costs, and since bromine is difficult to separate from the waste liquid, it is difficult to recycle, resulting in environmental pollution
[0006] In addition, the method in the prior art is also difficult to avoid the formation of by-product 1,2-dibromo-3,4,5-trifluorobenzene

Method used

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  • A kind of preparation method of 3,4,5-trifluorobromobenzene compound

Examples

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preparation example Construction

[0052] Preparation of Composite Zeolite Solid Superacid Catalyst

[0053] Step (1): Zeolite pretreatment

[0054] A1

[0055] After roasting the mordenite carrier at 450°C, add an ammonium nitrate solution with an ammonium ion concentration of 1.0mol / L for exchange treatment. The volume ratio of ammonium salt solution to zeolite liquid to solid is 4:1, and the exchange time is 6 hours. Repeat 4 times, wash the exchanged mordenite with deionized water, then dry it and bake it again at 450°C;

[0056] Put the aforementioned zeolite that has been roasted again into H2 with a concentration of 6mol / L 2 SO 4 Soak in the solution for 6 hours, wash with deionized water until neutral, dry, and bake at 450° C. for 8 hours to obtain a pretreated carrier.

[0057] A2

[0058] After roasting the mordenite carrier at 650°C, add an ammonium sulfate solution with an ammonium ion concentration of 0.05mol / L for exchange treatment. The volume ratio of ammonium salt solution to zeolite liqui...

Embodiment 1

[0110] Embodiment 1: the preparation of 3,4,5-trifluorobromobenzene

[0111] 500 milliliters of water, 147 grams of 2,3,4-trifluoroaniline, 214.5 grams of glacial acetic acid (98% in mass concentration, 3.5 moles) were put into the reactor, and sulfuric acid was added dropwise at 25-30°C to control the temperature in the reactor. 450 grams (mass concentration is 98%, 4.5 moles), control the temperature in the reactor to react at 25~30 ℃ for 1 hour after the addition is completed, add ammonium carbonate to adjust the pH of the reaction system to 9-10. Then add 80 grams of the catalyst 2 in the aforementioned Table 1 and 0.4 moles of bromine, control the temperature in the reactor to be 35-40° C., add hydrogen peroxide and water for dilution dropwise, and keep the reaction under stirring after the dropwise addition is completed. During the heat preservation reaction, the product mixture obtained from the heat preservation reaction is sampled, the sample is neutralized to PH=6~8 ...

Embodiment 2

[0116] Embodiment 2: the preparation of 3,4,5-trifluorobromobenzene

[0117] Example 1 was repeated except that 150 grams of catalyst 2 in Table 1 was added to obtain 181.1 grams of 3,4,5-trifluorobromobenzene with a yield of 88.7%. The by-product 1,2-dibromo-3,4,5-trifluorobenzene was not detected.

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Abstract

The invention relates to a preparation method of a 3,4,5-trifluorobromobenzene compound. The method is widely applied to the fields of medicines and pesticides. The method is simple in process, relatively low in cost, mild in condition, good in environment and high in safety; and formation of a byproduct 1,2-dibromo-3,4,5-trifluoro-benzene can be avoided.

Description

technical field [0001] The invention relates to the field of preparation of pesticides and pharmaceutical intermediates, in particular to a preparation method of 3,4,5-trifluorobromobenzene compound. Background technique [0002] The molecular formula of 3,4,5-trifluorobromobenzene is C 6 h 2 BrF 3 , the molecular weight is 210.98, and the CAS registration number is 138526-69-9. 3,4,5-trifluorobromobenzene undergoes Grignard reaction to realize various functionalization, and further synthesizes various polyfluorine-substituted compounds, so it is widely used in liquid crystal materials , pharmaceutical and pesticide intermediates, etc. [0003] WO2013041497A1 discloses a method for synthesizing a cathepsin C inhibitor with 3,4,5-trifluorobromobenzene as a raw material. In this method, 3,4,5-trifluorobromobenzene is first converted into boron reagent, and then combined with halogen Aromatic substrates are used for coupling; Dhayalan Vasudevan discloses a method for synthe...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C25/13C07C17/35
Inventor 何人宝王莺妹邵鸿鸣金逸中周日喜
Owner ZHEJIANG YONGTAI TECH CO LTD
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