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Synthesis method for 2-bromo-2,2-difluoroethylamine hydrochloride

A technology for difluoroethylamine hydrochloride and difluoroacetamide is applied in the field of synthesizing 2-bromo-2,2-difluoroethylamine hydrochloride, and the synthesis cost is reduced, the raw materials are cheap and easy to obtain, and the product quality is excellent. Effect

Inactive Publication Date: 2012-11-28
天津特安化学科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] The problem to be solved in the present invention is that a cheap and easy-to-obtain raw material is adopted: ethyl bromodifluoroacetate, and the last step of the amide reduction reaction adopts cheap and easily-available sodium borohydride as a reducing agent without using an expensive rhodium catalyst , developed a method for the synthesis of 2-bromo-2,2-difluoroethylamine hydrochloride

Method used

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  • Synthesis method for 2-bromo-2,2-difluoroethylamine hydrochloride
  • Synthesis method for 2-bromo-2,2-difluoroethylamine hydrochloride
  • Synthesis method for 2-bromo-2,2-difluoroethylamine hydrochloride

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] First step response:

[0020]

[0021] 700 g of ethyl 2-bromo-2,2-difluoroacetate was dissolved in 350 g of ether (the mass ratio of ethyl 2-bromo-2,2-difluoroacetate to ether was 2:1). Ammonia gas was continuously fed into the solution until the reaction of raw materials was detected by gas chromatography. The solvent was distilled off under reduced pressure to obtain a solid, which was washed with n-hexane and filtered. The filter cake was washed with n-hexane and dried under vacuum to obtain 600 g of off-white solid 2-bromo-2,2-difluoroacetamide, which was directly used in the next reaction without further purification.

[0022] Second step reaction:

[0023]

[0024] 600 grams of 2-bromo-2,2-difluoroacetamide was dissolved in 4.2 kg of tetrahydrofuran (the mass ratio of 2-bromo-2,2-difluoroacetamide and tetrahydrofuran was 1:7), and 350 grams of hydroboration was added Sodium (the molar ratio of 2-bromo-2,2-difluoroacetamide and sodium borohydride is 1:2.6)...

Embodiment 2

[0026] First step response:

[0027] 2 kg of ethyl 2-bromo-2,2-difluoroacetate was dissolved in 1.4 kg of ether (the mass ratio of ethyl 2-bromo-2,2-difluoroacetate to ether was 2:1.4). Ammonia gas was continuously fed into the solution until the reaction of raw materials was detected by gas chromatography. The solvent was distilled off under reduced pressure to obtain a solid, which was washed with n-hexane and filtered. The filter cake was washed with n-hexane and dried under vacuum to obtain 1.8 kg of off-white solid 2-bromo-2,2-difluoroacetamide, which was directly used in the next reaction without further purification.

[0028] Second step reaction:

[0029] 1.8 kg of 2-bromo-2,2-difluoroacetamide was dissolved in 13 kg of tetrahydrofuran (the mass ratio of 2-bromo-2,2-difluoroacetamide and tetrahydrofuran was 1:7.2), and 1 kg of hydroboration Sodium (the molar ratio of 2-bromo-2,2-difluoroacetamide and sodium borohydride is 1:2.5). Then control the reaction temperatu...

Embodiment 3

[0031] First step response:

[0032] 1 kg of ethyl 2-bromo-2,2-difluoroacetate was dissolved in 500 g of ether (the mass ratio of ethyl 2-bromo-2,2-difluoroacetate to ether was 2:1). Ammonia gas was continuously fed into the solution until the reaction of raw materials was detected by gas chromatography. The solvent was distilled off under reduced pressure to obtain a solid, which was washed with n-hexane and filtered. The filter cake was washed with n-hexane and dried under vacuum to obtain 880 g of off-white solid 2-bromo-2,2-difluoroacetamide, which was directly used in the next reaction without further purification.

[0033] Second step reaction:

[0034] 880 grams of 2-bromo-2,2-difluoroacetamide were dissolved in 5.3 kilograms of tetrahydrofuran (the mass ratio of 2-bromo-2,2-difluoroacetamide and tetrahydrofuran was 1:6), and 387 grams of hydroboration Sodium (the molar ratio of 2-bromo-2,2-difluoroacetamide and sodium borohydride is 1:2). Then control the reaction ...

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Abstract

The invention relates to a synthesis method for 2-bromo-2,2-difluoroethylamine hydrochloride. Ethyl bromodifluoroacetate is dissolved in ether; then ammonia gas is fed into the solution until the reaction is complete; the solvent is evaporated to get a solid 2-bromo-2,2-difluoroacetamide under reduced pressure; 2-bromo-2,2-difluoroacetamide is dissolved in tetrahydrofuran and is added with sodium borohydride; the temperature is controlled at 0-10 degrees; boron trifluoride etherate is added dropwise; the mixture is stirred continuously overnight at room temperature; the reaction is complete; saturated sodium hydroxide aqueous solution is added to the mixture for a quenching reaction; the mixture is extracted by dichloromethane; the organic phase is distilled after washing by a saturated aqueous solution of sodium chloride; and hydrochloric acid gas is added to the fraction to make the pH be less than 3, so a white solid of 2-bromo-2,2-difluoroethylamine hydrochloride is obtained. The core of the synthesis method is the use of an inexpensive and easily obtained ethyl bromodifluoroacetate and sodium borohydride as the reducing agents. The synthesis method helps to significantly reduce the cost, and is suitable for mass synthesis scale in kilograms.

Description

technical field [0001] The invention relates to the technical field of organic photosensitive materials, and relates to a method for synthesizing 2-bromo-2,2-difluoroethylamine hydrochloride. Background technique [0002] The vigorous development of the integrated circuit and liquid crystal display industry has rapidly increased the demand for photoresist (Photoresist). Photo Acid Generator (PAG, Photo Acid Generator) is an important component of photoresist. And 2-bromo-2,2-difluoroethylamine hydrochloride is an important precursor for us to develop a new class of photoacid generators. Therefore, it is necessary to explore the synthetic method of this product. The synthesis method of a similar structure is shown in US Patent U2010 / 0222593A1: this step of amide reduction reaction uses rhodium trichloride hydrate as a catalyst. Hydrated rhodium trichloride is expensive, the current price of Bailingwei: 1g2970 yuan, not suitable for large-scale synthesis. [0003] Amide re...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C211/15C07C209/50
Inventor 刘杨陈禹全祝士忠李茜
Owner 天津特安化学科技有限公司
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