Preparation method of ethyl difluoroacetate and intermediate thereof

A technology of ethyl difluoroacetate and ethanol, which is applied in the field of preparation of ethyl difluoroacetate and its intermediates, can solve the problems of large amount of three wastes, high equipment requirements, and high production costs, and achieve the purpose of suppressing the production of ether and water, The effect of shortening reaction time and reducing product loss

Active Publication Date: 2013-08-21
JIANGSU LIANHE CHEM TECH +4
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The technical problem to be solved by the present invention is that, in order to solve the defects in the prior art that the preparation process of ethyl difluoroacetate requires high equipment, low yield, high production cost, large amount of three wastes, long reaction route, and unfavorable industrial production, etc., And provide a kind of preparation method of ethyl difluoroacetate and intermediate thereof

Method used

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  • Preparation method of ethyl difluoroacetate and intermediate thereof
  • Preparation method of ethyl difluoroacetate and intermediate thereof
  • Preparation method of ethyl difluoroacetate and intermediate thereof

Examples

Experimental program
Comparison scheme
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Embodiment 1

[0081] Step 1. Add 73.2g (1mol) of methylisopropylamine and 400g of toluene to a 1000ml dry flask, add 147.4g (1mol) of dichloroacetyl chloride dropwise at 20-30°C, and keep warm for 0.5-1h after the addition. Add 147.4 g of water to wash the layers, and the organic layer is concentrated under reduced pressure to obtain 180.3 g (0.98 mol) of N-methyl-N-isopropyl-2,2-dichloroacetamide. The yield is 98%, and the purity is >99.0%.

[0082] Step 2. Add 132.5 (2.28mol) KF, catalyst p-tert-butyl[6]calixarene 8g, solvent DMF692g, 180.3g (0.98mol) N-methyl-N-isopropyl-2,2 to a 1000ml flask -Dichloroacetamide was kept at 90-100°C for 4-5h, filtered, concentrated by distillation to obtain 140.8g (0.931mol) N-methyl-N-isopropyl-2,2-difluoroacetamide, yield 95% ; Purity 99.5%.

[0083] Step 3. Add 184.2g (1.88mol) of concentrated sulfuric acid to a 500ml flask, and add 140.8g (0.931mol) of N-methyl-N-isopropyl-2,2-difluoroacetamide dropwise at a temperature of 95°C to 100°C And 45.2g (...

Embodiment 2

[0085] Step 1. Add 146.4g (2mol) of methylisopropylamine and 400g of toluene to a 1000ml dry flask, add 147.4g (1mol) of dichloroacetyl chloride dropwise at 20-30°C, and keep warm for 0.5-1h after the addition. Add 147.4 g of water to wash the layers, and the organic layer is concentrated under reduced pressure to obtain 181.8 g (0.988 mol) of N-methyl-N-isopropyl-2,2-dichloroacetamide. The yield is 99%, and the purity is >99.0%.

[0086] Step 2. Add 132.5 (2.28mol) KF, catalyst p-tert-butyl[6]calixarene 8g, solvent DMF692g, 181.8g (0.988mol) N-methyl-N-isopropyl-2,2 into a 1000ml flask - Dichloroacetamide was kept at 90-100°C for 4-5h, filtered, concentrated by distillation to obtain 141.8g (0.938mol) N-methyl-N-isopropyl-2,2-difluoroacetamide, yield 95% ; Purity 99.5%.

[0087]Step 3. Add 184.2g (1.88mol) of concentrated sulfuric acid to a 500ml flask, and add 141.8g (0.938mol) of N-methyl-N-isopropyl-2,2-difluoroacetamide dropwise at a temperature of 95°C to 100°C And 45...

Embodiment 3

[0089] Step 1. Add 182.8g (2.5mol) of methylisopropylamine and 400g of toluene into a 1000ml dry flask, add 147.4g (1mol) of dichloroacetyl chloride dropwise at 20-30°C, and keep warm for 0.5-1h after the addition. Add 147.4 g of water to wash the layers, and the organic layer is concentrated under reduced pressure to obtain 181.8 g (0.988 mol) of N-methyl-N-isopropyl-2,2-dichloroacetamide. The yield is 99%, and the purity is >99.0%.

[0090] Step 2. Add 278.2 (2.96mol) KF, 8g catalyst p-tert-butyl[6]calixarene, 692g solvent DMF, and 181.8g (0.988mol) N-methyl-N-isopropyl-2,2 to a 1000ml flask -Dichloroacetamide was kept at 90-100°C for 4-5h, filtered, concentrated by distillation to obtain 142.6g (0.943mol) N-methyl-N-isopropyl-2,2-difluoroacetamide, yield 95.4% ; Purity 99.5%.

[0091] Step 3. Add 184.2g (1.88mol) of concentrated sulfuric acid to a 500ml flask, and add 142.6g (0.943mol) of N-methyl-N-isopropyl-2,2-difluoroacetamide dropwise at 95°C to 100°C And 45.2g (0.9...

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Abstract

The invention discloses a preparation method of ethyl difluoroacetate and an intermediate thereof. The preparation method comprises the following steps of: dropwise adding a mixed solution of a compound I and ethanol to concentrated sulfuric acid at a temperature in the range from 90 to 110 DEG C for reacting, and simultaneously, distilling out generated ethyl difluoroacetate in the dropwise adding process, wherein each of R1 and R2 independently represents phenyl or C1-3 linear-chain or branch-chain alkyl, respectively and when each of R1 and R2 independently is the C1-3 linear-chain or branch-chain alkyl, R1 and R2 are different; and the preparation of the compound I comprises the steps of mixing a compound II with potassium fluoride for reacting in the presence of a catalyst namely a calixarene compound in a solvent; and the preparation of the intermediate compound II comprises the steps of mixing a compound III with a solvent, and dropwise adding dichloroacetyl chloride at a temperature in the range from -15 to 150 DEG C for reacting. The preparation method disclosed by the invention employs dichloroacetyl chloride and secondary amine as starting raw materials, and is simple and convenient in production process, low in quantity of three wastes, high in yield and suitable for industrial production.

Description

technical field [0001] The invention relates to a preparation method of ethyl difluoroacetate and its intermediate. Background technique [0002] Ethyl difluoroacetate is an important pharmaceutical, pesticide and chemical intermediate. [0003] At present, there are many methods for preparing ethyl difluoroacetate, wherein the following methods are arranged: [0004] Method 1, EP0694523 discloses a preparation method of ethyl difluoroacetate, which is to add tetrafluoroethylene and methanol under the catalysis of a catalyst to synthesize methoxytetrafluoroethane, methoxytetrafluoroethane Catalytic cracking to obtain difluoroacetyl fluoride, and then esterify with ethanol to obtain ethyl difluoroacetate. [0005] Method 2, JP7242587 discloses a preparation method of ethyl difluoroacetate, which involves reacting tetrafluoroethylene, diethylamine and water in an autoclave to obtain N,N-diethyldifluoroacetamide, N, N-diethyldifluoroacetamide is then hydrolyzed to obtain dif...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C69/63C07C67/20C07C231/12C07C231/02C07C233/05C07C233/07
Inventor 樊小彬林行军杨威
Owner JIANGSU LIANHE CHEM TECH
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