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Preparation method of 3-trifluoromethylpyrazole intermediate

A technology for trifluoromethylpyrazole and intermediates, which is applied in the field of preparation of 3-trifluoromethylpyrazole intermediates, can solve the problems of unfavorable industrial production, cumbersome post-processing steps, and harsh reaction conditions, and achieve production costs Low, simple after-treatment steps, less reaction steps

Inactive Publication Date: 2015-02-04
联化科技(上海)有限公司 +2
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0008] The technical problem to be solved by the present invention is to overcome the existing 4-ethoxy-1,1,1-trifluoro-3-buten-2-one preparation method with many reaction steps, harsh reaction conditions, serious environmental pollution, Aftertreatment steps are loaded down with trivial details, reaction yield is low, production cost is high, be unfavorable for the defects such as suitability for industrialized production and provide the preparation method of 3-trifluoromethylpyrazole intermediate, the preparation method of the present invention has few reaction steps, reaction condition mildness, Environmentally friendly, simple post-processing steps, high reaction yield, high product purity, low production cost, suitable for industrial production

Method used

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Examples

Experimental program
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Effect test

Embodiment 1

[0039] Add 26.56g (0.368mol) of vinyl ethyl ether, 450g toluene, and 53.25g (0.526mol) of triethylamine into a 1000mL four-necked flask equipped with a thermometer, a condenser, and an exhaust gas absorption device. 30g (0.263mol) of fluoroacetic acid is controlled at a temperature lower than 20°C, the dropwise addition is completed in 0.5 hours, the temperature is lowered to 0°C, and it takes about 1 hour to feed 31.5g (0.316mol) of phosgene; the temperature is slowly raised to 0°C and kept for 5 hours. Add 100g of water dropwise, stir and keep warm at 10°C for 0.5 hours, let stand, separate layers, add 100g of NaHCO with a mass percentage of 5% to the organic layer 3 The aqueous solution was stirred and incubated for 0.5 hours (the mass percentage refers to the percentage of the mass of sodium bicarbonate in the total mass of the sodium bicarbonate aqueous solution), allowed to stand, and layered; the organic layer was dehydrated to obtain 4-ethoxyl-1,1,1 -Toluene solution o...

Embodiment 2

[0041] Add 20.87g (0.289mol) of vinyl ethyl ether, 150g xylene, and 52.03g (0.658mol) of pyridine into a 500mL four-neck flask equipped with a thermometer, condenser, and tail gas absorption device, cool down in an ice bath to 0°C, and drop trifluoro 30g (0.263mol) of acetic acid is controlled at a temperature lower than 20°C, the dropwise addition is completed in 0.5 hours, the temperature is lowered to 0°C, and it takes about 1 hour to introduce 34.36g (0.347mol) of phosgene; the temperature is slowly raised to 10°C, and the temperature is kept for 3 hours. Add 100g of water dropwise, stir and keep warm at 10°C for 0.5 hours, let stand, separate layers, add 100g to the organic layer with a mass percentage of 5% NaHCO 3 The aqueous solution was stirred and incubated for 0.5 hours (the mass percentage refers to the percentage of the mass of sodium bicarbonate in the total mass of the sodium bicarbonate aqueous solution), allowed to stand, and layered; the organic layer was dehy...

Embodiment 3

[0043] Add 19g (0.263mol) of vinyl ether, 600g of dichloromethane, and 83.25g (1.052mol) of pyridine into a 1000mL four-neck flask equipped with a thermometer, condenser, and tail gas absorption device, cool down in an ice bath to 0°C, and dropwise add trifluoro 30g (0.263mol) of acetic acid is controlled at a temperature lower than 20°C, and the dropwise addition is completed in 0.5 hours. After cooling down to 0°C, it takes about 1 hour to feed 54.65g (0.526mol) of phosgene; Add 100g of water, stir and keep warm at 10°C for 0.5 hours, let stand, separate layers, add 100g of NaHCO with a mass percentage of 5% to the organic layer 3 The aqueous solution was stirred and incubated for 0.5 hours (the mass percentage refers to the percentage of the mass of sodium bicarbonate in the total mass of the sodium bicarbonate aqueous solution), allowed to stand, and layered; the organic layer was dehydrated to obtain 4-ethoxyl-1,1,1 - Dichloromethane solution of trifluoro-3-buten-2-one, 4...

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Abstract

The invention discloses a preparation method of a 3-trifluoromethylpyrazole intermediate. The preparation method is characterized by comprising the following step: carrying out reaction on trifluoroacetic acid, an acylation reagent and vinyl alkyl ether disclosed as Formula 1 in an organic solvent in the presence of an acid-binding agent to obtain 4-alkoxy-1,1,1-trifluoro-3-butenyl-2-one, wherein the acylation reagent is one or more of phosgene, diphosgene and triphosgene, and R is C1-C6 alkyl group. The preparation method has the advantages of fewer reaction steps, mild reaction conditions, environment friendliness, simple after-treatment steps, high reaction yield, high product purity and low production cost, and is suitable for industrial production.

Description

technical field [0001] The present invention particularly relates to the preparation method of 3-trifluoromethylpyrazole intermediate. Background technique [0002] 4-Ethoxy-1,1,1-trifluoro-3-buten-2-one is an important intermediate for the preparation of 3-trifluoromethylpyrazole, and 3-trifluoromethylpyrazole can be used To synthesize anti-virus, antibiotics, fungicides, herbicides, etc., and can also be used to synthesize intermediates of respiratory system drugs, such as antitussives. Its synthesis method has been reported at home and abroad. [0003] In the literature, the synthetic methods of 4-ethoxy-1,1,1-trifluoro-3-buten-2-one mainly contain the following types: [0004] (1) It is obtained by reacting trifluoroacetic anhydride and vinyl ethyl ether in a solvent in the presence of a base, including pyridine, 4-dimethylaminopyridine (4-DMAP), methyl tert-butyl ether, and triethylamine et al. (Journal of Fluorine Chemistry, 2011, 132, 850-857). After using trifluo...

Claims

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Application Information

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IPC IPC(8): C07C49/255C07C45/45
CPCY02P20/582C07C45/47C07C45/86C07C49/255
Inventor 樊小彬徐晓明郭胜强
Owner 联化科技(上海)有限公司
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