Method for preparing 2,3,3,3-tetrafluoropropene

A technology of tetrafluoropropene and tetrafluoropropanol, which is applied in the field of preparation of 2,3,3,3-tetrafluoropropene, can solve the problems of waste of fluorine element and low utilization rate of fluorine element, and achieves low equipment requirements and conditions. Mild, easy-to-industrial effect

Inactive Publication Date: 2018-05-04
HANGZHOU NORMAL UNIVERSITY +1
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  • Abstract
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Problems solved by technology

The mainstream production process of florfenicol in China uses Ishikawa reagent (N,N-diethyl-1,1,2,3,3,3-hexafluoropropylamine) for fluorination, and the utilization rate of fluorine is relatively low. Low, the produced by-product N,N-diethyl-2,3,3,3-tetrafluoropropionamide reaches more than 1,000 tons / year, which not only causes waste of fluorine, but also brings huge environmental pressure to the production of enterprises

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  • Method for preparing 2,3,3,3-tetrafluoropropene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0038] Hydrolysis reaction:

[0039] Add 603.5g (3.0mol) of N,N-diethyl-2,3,3,3-tetrafluoropropionamide and 440.6g (5.0mol) of 1,4-dioxane into a 3000mL three-necked glass reaction flask, mechanically Add dropwise 85% sulfuric acid solution 691.8g (H 2 SO 4 6.0mol), after the drop, the temperature rose to 100°C, and the temperature was maintained for 10 hours. Fluoropropionic acid, the gas chromatography analysis purity is 98.5%, the yield is 87.1%.

[0040] Reduction reaction:

[0041] Add NaBH to 1000mL three-necked glass reaction flask 3 CN 31.4g (0.5mol), tetrahydrofuran 200g (4.35mol), heated up to 40°C under magnetic stirring, added 73.0g (0.5mol) of 2,3,3,3-tetrafluoropropionic acid dropwise, and kept the reaction at 50°C after dropping 3 hours. After the reaction is complete, lower the temperature to 10°C, add 200g of deionized water dropwise, extract the reaction solution with ethyl acetate (100mL×3 times), combine the extracts, carry out atmospheric distillatio...

Embodiment 2

[0047] Hydrolysis reaction:

[0048] Add 603.5g (3.0mol) of N,N-diethyl-2,3,3,3-tetrafluoropropionamide and 440.6g (5.0mol) of 1,4-dioxane into a 3000mL three-necked glass reaction flask, mechanically Add 608g of concentrated hydrochloric acid (HCl6.0mol) dropwise under stirring, the internal temperature rises to 80°C after dropping, and keep it warm for 12 hours. 2,3,3,3-Tetrafluoropropionic acid has a gas chromatography purity of 97.7% and a yield of 73.0%.

[0049] Reduction reaction:

[0050] Add LiAlH to a 1000mL three-necked glass reaction flask 4 19g (0.5mol), 200g (4.35mol) of absolute ethanol, heated to 40°C under magnetic stirring, slowly added 73.0g (0.5mol) of 2,3,3,3-tetrafluoropropionic acid dropwise, and kept at 50°C after dropping React for 3 hours. After the reaction is complete, lower the temperature to 10°C, add 200g of deionized water dropwise, extract the reaction solution with ethyl acetate (100mL×3 times), combine the extracts, carry out atmospheric...

Embodiment 3

[0056] Hydrolysis reaction:

[0057] Add 603.5g (3.0mol) of N,N-diethyl-2,3,3,3-tetrafluoropropionamide and 54.0g (3.0mol) of deionized water into a 3000mL three-necked glass reaction flask, add 85 % sulfuric acid solution 691.8g (H 2 SO 4 6.0mol), the temperature rose to 100°C after dripping, and kept for 10 hours. After the reaction was completed, rectification at atmospheric pressure collected 119.5-120.5°C fractions to obtain 377.3g of colorless liquid, which was 2,3,3,3-tetra Fluoropropionic acid, the gas chromatography analysis purity is 99.0%, the yield is 85.3%.

[0058] Reduction reaction:

[0059] Add NaBH to 1000mL three-necked glass reaction flask 4 18.9g (0.5mol), 34.1g (0.25mol) of zinc chloride, 200g (4.35mol) of absolute ethanol, heated to 40°C under magnetic stirring, slowly added dropwise 73.0 g of 2,3,3,3-tetrafluoropropionic acid g (0.5 mol), after the dropwise reaction at 60°C for 3 hours. After the reaction is complete, lower the temperature to 10...

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Abstract

The invention relates to a method for preparing 2,3,3,3-tetrafluoropropene. The method comprises the following steps: (1) by taking a by-product N,N-diethyl-2,3,3,3-tetrafluoropropylamide of an Ishikawa's reagent as a raw material, hydrolyzing under acidic or alkaline conditions to obtain 2,3,3,3-tetrafluoropropionic acid; (2) contacting the 2,3,3,3-tetrafluoropropionic acid with a reducing agentin the presence of a catalyst or in a catalyst-free system so as to obtain 2,3,3,3-tetrafluoropropanol; and (3) reacting the 2,3,3,3-tetrafluoropropanol in the presence of a dehydrating agent, therebyobtaining the 2,3,3,3-tetrafluoropropene. The method disclosed by the invention is simple in operation, mild in conditions and low in equipment requirements, recycling of the by-product is realized,and industrialized application is easily realized.

Description

technical field [0001] The invention relates to a preparation method of refrigerant, in particular to a preparation method of 2,3,3,3-tetrafluoropropene. Background technique [0002] In the vapor compression refrigeration system, the refrigerant is vividly called "blood". 1,1,1,2-tetrafluoroethane (HFC-134a), does not damage the ozone layer, has good safety performance (non-flammable, non-explosive, non-toxic, non-irritating, non-corrosive), making It has become a very effective and safe substitute for R12 (dichlorodifluoromethane), and is the most widely used third-generation automotive refrigerant. However, HFC-134a is a greenhouse gas with a GWP value of 1340 (relative to CO 2 In terms of), according to the provisions of the Montreal Protocol, will be phased out and banned. In the search for a replacement for HFC-134a, 2,3,3,3-tetrafluoropropene (HFO-1234yf) has zero ozone depletion potential (ODP=0), very low greenhouse effect potential (GWP=4 ), stand out among man...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C17/35C07C21/18
CPCC07C17/35C07C29/149C07C51/06C07C21/18C07C31/38C07C53/21
Inventor 章鹏飞吴海锋赵国标叶盛徐龙
Owner HANGZHOU NORMAL UNIVERSITY
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