Preparation method of 2-fluoro-4-cyano trifluorotoluene

A technology of cyanobenzotrifluoride and chlorobenzotrifluoride, which is applied in the field of preparation of 2-fluoro-4-cyanobenzotrifluoride, can solve the problems of expensive raw materials, high raw material prices, and complicated processes, and achieve the goal of reducing impurities The effect of generating, improving product purity, and improving conversion yield

Pending Publication Date: 2022-03-25
阜新金特莱氟化学有限责任公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In a dry state, some diazonium salts are unstable and highly active, and can decompose or even explode when subjected to heat, friction, impact, etc.; the sodium nitrite used in the diazotization production process is an inorganic oxidant, which can decompose, Reacts with organic matter to cause fire or explosion; the reaction raw materials are explosive
This reaction is a dangerous process, and the cost of raw materials is high, and the market supply is small
The second method: the trifluoromethyl method on the vacancy. The disadvantage of this reaction is that the pro

Method used

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  • Preparation method of 2-fluoro-4-cyano trifluorotoluene
  • Preparation method of 2-fluoro-4-cyano trifluorotoluene
  • Preparation method of 2-fluoro-4-cyano trifluorotoluene

Examples

Experimental program
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Effect test

Embodiment 1

[0026] A preparation method of 2-fluoro-4-cyanobenzotrifluoride, prepared according to the following method: the reaction chemical formula is as follows

[0027]

[0028] The preparation method is as follows:

[0029] (1) Preparation of activated zinc powder (used for the preparation of tetrakis(triphenylphosphine) nickel)

[0030] Add 10L methyl ethyl ketone and 1kg acetic acid to a 20L four-necked bottle, start stirring, add 10kg zinc powder, use a heating mantle to raise the temperature of the system to reflux to 75°C, cool down to T<40°C after 2 hours, and pour the activated zinc powder system into Put it into the system ① in a 50L barrel for use.

[0031] (2) Preparation of four (triphenylphosphine) nickel (main reaction catalyst)

[0032] 1. Add 7kg of anhydrous nickel chloride, 62.5kg of triphenylphosphine, and 130kg of DMF into a dry and clean 200L oil bath kettle, use the jacket of the oil bath kettle to raise the temperature of the system to T=168~172℃, and stea...

Embodiment 2

[0041] The difference from Example 1 is: add 7kg of anhydrous nickel chloride, 52.5kg of triphenylphosphine, and 150kg of DMF to a dry and clean 200L oil bath kettle, and use the jacket of the oil bath kettle to raise the temperature of the system to T=168~ At 172°C, 80kg of DMF can be evaporated in about 2 hours, then nitrogen gas is passed into the oil bath kettle, and the temperature is lowered to T=60-70°C under the protection of nitrogen gas, and the system ② is obtained for use.

Embodiment 3

[0043] The difference from Example 1 is: add 7kg of anhydrous nickel chloride, 62.5kg of triphenylphosphine, and 130kg of DMF to a dry and clean 200L enamel kettle, and use the jacket of the enamel kettle to raise the temperature of the system to T=120~130℃ , about 2 hours to steam out 80kg of DMF, and then pass nitrogen into the oil-bath kettle, nitrogen protection to lower the temperature to T = 60 ~ 70 ℃, the system ② is ready to use. Embodiment Four

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Abstract

The invention relates to the field of synthesis of medical intermediates, in particular to a preparation method of 2-fluoro-4-cyanobenzotrifluoride. The preparation method comprises the following steps: activating zinc powder, preparing a catalyst tetrakis (triphenylphosphine) nickel, adding a main reactant 2-fluoro-4-chlorobenzotrifluoride, and reacting to obtain the 2-fluoro-4-cyanobenzotrifluoride. The raw materials adopted in the method are large in supply in the market and low in price. In the reaction process, full reaction conversion with the prepared activated zinc powder can be realized, so that full conversion is ensured, and generation of impurities is reduced. The conversion yield and the product purity are improved. In the whole process, nitrogen is continuously introduced to ensure that combustibles in the reaction are cooled to a safe state under the protection of inert gas, and meanwhile, air suck-back can be prevented.

Description

technical field [0001] The invention relates to the field of synthesis of pharmaceutical intermediates, in particular to a preparation method of 2-fluoro-4-cyanobenzotrifluoride. Background technique [0002] 2-Fluoro-4-cyanobenzotrifluoride is a very important pharmaceutical intermediate, which is widely used. However, there are many problems in the preparation of 2-fluoro-4-cyanobenzotrifluoride. The following preparations are currently available: Several methods: The first one: the diazotization reaction is the halogen replacement method. The reaction is through the diazonium salt at a slightly higher temperature or under the action of light, especially the diazonium salt containing nitro is very easy to decompose, and some even It can also decompose at room temperature. In a dry state, some diazonium salts are unstable and highly active, and can decompose or even explode when subjected to heat, friction, impact, etc.; the sodium nitrite used in the diazotization product...

Claims

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Application Information

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IPC IPC(8): C07C253/14C07C255/50B01J31/24
CPCC07C253/14B01J31/2404B01J2531/847C07C255/50
Inventor 吴永才刘鹏飞石浚陈晓光那思博
Owner 阜新金特莱氟化学有限责任公司
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