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Preparation method for carboxylation of C-H bond of halogen-containing aromatic hydrocarbon

A halogen-containing and carboxylated technology, applied in the field of aromatic carboxylic acid, can solve the problems of unacceptable cost and safety requirements, flammable and explosive raw materials of butyllithium, and poor control of the reaction process, and achieve more emission reduction of three wastes. , Conducive to the effect of industrialization and safety improvement

Pending Publication Date: 2022-07-29
江苏百康德医药科技有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

There are two main synthesis methods reported in the literature: one is the ultra-low temperature synthesis of butyllithium, the process is complicated and the yield is unstable, and the raw material of butyllithium is flammable and explosive, and the ultra-low temperature operation is limited and the equipment investment is high and the reaction process It is not easy to control; the second is to use aluminum trichloride to induce and catalyze the Friedel-Crafts reaction synthesis of acetyl chloride, which is easy to generate a large amount of aluminum-containing wastewater in the process, and subsequent oxidation of oxidants such as sodium hypochlorite to carboxyl targets is required, and the cost and safety requirements are unacceptable

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  • Preparation method for carboxylation of C-H bond of halogen-containing aromatic hydrocarbon
  • Preparation method for carboxylation of C-H bond of halogen-containing aromatic hydrocarbon
  • Preparation method for carboxylation of C-H bond of halogen-containing aromatic hydrocarbon

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preparation example Construction

[0013] like figure 1 As shown, the present invention provides a preparation method for the C-H bond carboxylation of halogen-containing aromatic hydrocarbons, comprising the following steps: in an organic solvent, adding halogen-containing aromatic hydrocarbons and a base, a phase transfer catalyst, and carbon dioxide at a certain temperature to carry out a one-step atmospheric carboxylation The reaction obtains the target product, wherein the reaction formula is:

[0014]

[0015] In this embodiment, specifically, the preparation process for the C-H bond carboxylation of halogen-containing aromatic hydrocarbons includes the following steps: adding organic solvent, halogen-containing aromatic hydrocarbons, alkali, and phase transfer catalyst to the reaction vessel in sequence under nitrogen protection, and stirring evenly Then the temperature is raised to the set temperature, and carbon dioxide is bubbled from the bottom of the kettle; at the set temperature, the temperatur...

Embodiment 1

[0024] 2-Chloro-3-fluoro-4-trifluoromethylbenzoic acid

[0025]

[0026] Small test preparation of the target product:

[0027] In the 500mL reactor, drop into 2-fluoro-3-chloro-trifluorotoluene 19.8g (0.10mol), potassium fluoride 6g (0.11mol), NMP100g, 15-crown ether-5 catalyst 2g, potassium tert-butoxide 15g with heating and stirring , set the carbon dioxide bubbling pressure to 0.1MP, raise the temperature to 150°C and react for 5h, cool down, recover NMP under reduced pressure, the recovery rate is 95%, add 50mL of water, adjust pH=2, stir and crystallize, and filter with suction to obtain >98% of the target 2-Chloro-3-fluoro-4-trifluoromethylbenzoic acid 19.4 g, yield 80%.

Embodiment 2

[0029] 2,3-Difluoro-4-trifluoromethylbenzoic acid

[0030]

[0031] Small test preparation of the target product:

[0032] 18.2g (0.10mol) of 2,3-difluoro-trifluorotoluene, 15g (0.1mol) of cesium fluoride, 100g of DMI, 2g of 18-crown ether-6 catalyst, 14g of sodium tert-butoxide were heated and stirred in the 500mL reactor. , set the carbon dioxide bubbling pressure to 0.1MP, heat up to 180°C for reaction 5h, cool down, recover DMI under reduced pressure, the recovery rate is 95%, add 50mL of water, adjust pH=2, stir and crystallize, and suction filtration to obtain >98% of the target 2,3-difluoro-4-trifluoromethylbenzoic acid 20 g, yield 84%.

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Abstract

The invention belongs to the technical field of aromatic carboxylic acid, and particularly relates to a preparation method for carboxylation of a C-H bond of halogen-containing aromatic hydrocarbon, which comprises the following steps: adding halogen-containing aromatic hydrocarbon, alkali, a phase transfer catalyst and carbon dioxide into an organic solvent, and carrying out normal-pressure carboxylation one-step reaction to obtain a target product, according to the preparation method for carboxylation of the C-H bond of the halogen-containing aromatic hydrocarbon, the halogen-containing aromatic hydrocarbon carboxylic acid is obtained through one-step reaction of the halogen-containing aromatic hydrocarbon by using the alkali and the carbon dioxide, the raw material sources are many, the cost advantage is obvious, the preparation method is safer and more convenient, the total yield is high, the three wastes are few, particularly, the use of strong alkali such as butyl lithium and LDA is avoided, and the method is suitable for industrial production. Meanwhile, the high-temperature and high-pressure carboxylation reaction used by carbon dioxide in the past is avoided, so that the safety is greatly improved, the emission reduction of the three wastes is more, and industrialization is facilitated.

Description

technical field [0001] The invention belongs to the technical field of aromatic hydrocarbon carboxylic acids, and in particular relates to a preparation method for C-H bond carboxylation of halogen-containing aromatic hydrocarbons. Background technique [0002] Aromatic carboxylic acids containing halogens and electron-withdrawing groups are pharmaceutical and pesticide intermediates. In terms of pesticides, they can be used to synthesize herbicide HPPD inhibitors such as mesotrione, cyclopyrone, cyclopyrazone, isoxaflutole , Oxatrazone, etc. There are two main synthesis methods reported in the literature: one is the ultra-low temperature synthesis of butyllithium, the process is complex and the yield is unstable, the butyllithium raw material is flammable and explosive, the ultra-low temperature operation is limited, the equipment investment is high, and the reaction process is It is not easy to control; the second is the use of aluminum trichloride to induce and catalyze ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C51/15C07C63/70C07C315/04C07C317/44
CPCC07C51/15C07C315/04C07C63/70C07C317/44
Inventor 肖石基刘长生
Owner 江苏百康德医药科技有限公司