A kind of preparation method of 2,4-dichloro-5-fluoroacetophenone

A technology for fluoroacetophenone and dichlorofluorobenzene is applied in the field of synthesizing 2,4-dichloro-5-fluoroacetophenone with a zeolite magnetic composite carrier catalyst, and can solve the problems of high content, unfavorable reaction, difficult separation and the like, Achieve the effect of overcoming the difficulty of separation and recovery, facilitating sedimentation growth and reducing the cost of use

Active Publication Date: 2016-01-20
ZHEJIANG YONGTAI TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The difference between the melting points of the two is 10°C. At present, they are usually separated by repeated crystallization at low temperature. However, as the content of the by-product 2,6-dichloro-3-fluoroacetophenone increases, it is difficult to carry out repeated crystallization. separation of the two
However, they use aluminum trichloride as a catalyst, but aluminum trichloride is easy to sublime and condense and absorb water from the air, which is not good for the reaction.
In addition, 1 mole of acetyl chloride usually consumes more than 1 mole of aluminum trichloride, and aluminum trichloride is not renewable, which increases the difficulty of waste disposal and pollutes the environment
Finally, this method inevitably has a high content of the aforementioned by-product 2,6-dichloro-3-fluoroacetophenone, and there is a problem that the crystallization mother liquor is difficult to separate
[0007] The above existing processes all have problems such as high content of by-product 2,6-dichloro-3-fluoroacetophenone, which leads to the separation of crystallization mother liquor, difficult disposal of waste and environmental pollution, etc.

Method used

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  • A kind of preparation method of 2,4-dichloro-5-fluoroacetophenone

Examples

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preparation example Construction

[0048] Preparation of Composite Zeolite Solid Superacid Catalyst

[0049] Step (1): Zeolite pretreatment

[0050] A1

[0051] 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;

[0052] 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.

[0053] A2

[0054] 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

[0106] Embodiment 1: Preparation of 2,4-dichloro-5-fluoroacetophenone

[0107] In reactor, add 33 grams (0.2mol) 1,3-dichloro-4-fluorobenzene and 20.4 grams (0.26mol) acetyl chloride, then in reactor, add the catalyst 11 in 30 grams of aforementioned Table 1, react in 120 DEG C stirred and reacted for 60 minutes, then fed 500 milliliters of deionized water and 200 milliliters of toluene to the reaction mixture and continued to stir, after layering, the organic phase was separated from the water phase, and the gained water phase was further extracted with 200 milliliters of toluene. All the obtained organic phases were combined, toluene was removed by distillation, vacuum distillation was carried out after the temperature in the reactor reached 90°C, fractions at 100-120°C were collected, and finally 42.0 g of white crystals were obtained by freezing and crystallization, with a melting point of 33.5-34°C. was 92.1%.

[0108] Mass spectrometry and elemental analysis were carrie...

Embodiment 2

[0111] Embodiment 2: Preparation of 2,4-dichloro-5-fluoroacetophenone

[0112] Example 1 was repeated, except that the catalyst 11 regenerated 5 times was used, and finally 39.8 g of white crystals were obtained from the reaction, with a yield of 87.4%.

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Abstract

The invention relates to a method for synthesizing 2,4-dichloro-5-fluoroacetophenone suitable for industrial production. The yield of the 2,4-dichloro-5-fluoroacetophenone can be obviously improved; the yield of a by-product 2,6-dichloro-3-fluoroacetophenone is reduced; and the reusability of a catalyst is relatively good.

Description

technical field [0001] The invention relates to a preparation method of 2,4-dichloro-5-fluoroacetophenone, in particular to a method using loaded phosphotungstic acid / ZrO 2 A method for the synthesis of 2,4-dichloro-5-fluoroacetophenone using a zeolite magnetic composite support catalyst. Background technique [0002] Quinolones are a class of synthetic antibacterial drugs that mainly act on Gram-negative bacteria. They do not have cross-resistance with most antibacterial drugs, and have the characteristics of high efficiency, spectrum, and low toxicity, and have a good development prospect. [0003] 2,4-Dichloro-5-fluoroacetophenone is an important intermediate in the synthesis of quinolones (norfloxacin, ciprofloxacin, difloxacin hydrochloride, etc.), and it is a white or light yellow crystalline solid with a molecular weight of It is 207.03, the melting point is 33.5-34°C, and the CAS registration number is 704-10-9. It can be dissolved in organic solvents such as benzen...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C49/807C07C45/46B01J31/38
Inventor 何人宝王莺妹邵鸿鸣
Owner ZHEJIANG YONGTAI TECH CO LTD
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