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Preparation method of trimethylsilyl 2-(fluorosulfonyl) difluoroacetate

A technology of fluorosulfonyl difluoroacetic acid and trimethylsilyl, which is applied in the field of preparation of trimethylsilyl 2-difluoroacetate, can solve the problem of low yield of the preparation method, and achieve the goal of increasing the yield Effect

Active Publication Date: 2021-10-15
SHIJIAZHUANG SAN TAI CHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] The present invention proposes a preparation method of trimethylsilyl 2-(fluorosulfonyl) difluoroacetate, which solves the problem that the yield of the preparation method in the prior art is not high

Method used

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  • Preparation method of trimethylsilyl 2-(fluorosulfonyl) difluoroacetate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Connect a magnetic stirrer to a dry 1500ml three-necked round-bottomed flask, connect nitrogen to the inlet of the constant pressure dropping funnel, connect the outlet to a spare trap, and then connect to the outlet of the inverted glass funnel directly above the 1000mL beaker. Add 600ml of water and 120g of NaOH to the beaker.

[0026] Add 356.18g of anhydrous pyridine and 142.47g of triethylamine to the flask, add 178.09g of RUSA, control the temperature at -5°C-0°C, add dropwise 162.96g of trimethylchlorosilane, control the temperature at -5°C-0°C, Control the dropwise addition time at 1.5h. After the dropwise addition, heat to reflux and keep warm for 7h. After the reaction, take out the mixture, add methanol (the amount added is 10% of the volume of the mixture) and let it stand for 1.5h to separate the liquid, take the lower layer, and simply distill Heating to 50-60°C until no fraction evaporates; control the vacuum distillation pressure to 0.1MPa until no fract...

Embodiment 2

[0028] The reaction was carried out according to the apparatus of Example 1. Add 534.27g of anhydrous pyridine and 106.85g of triethylamine to the flask, add 178.09g of RUSA, control the temperature at -5°C-0°C, add dropwise 152.10g of trimethylchlorosilane, control the temperature at -5°C-0°C, Control the dropwise addition time at 1h20min. After the dropwise addition is completed, heat to reflux and keep the temperature for 6.5h. After the reaction, take out the mixture, add methanol (the amount added is 12% of the volume of the mixture) and let it stand for 1.5h to separate the liquid. Take the lower layer and simply distill it. Heat to 50-60°C until no fraction is distilled; control the vacuum distillation pressure to 0.1 MPa until no fraction is distilled to obtain the product TFDA with a yield of 90.1% in terms of RUSA and a purity of 92.1%.

Embodiment 3

[0030] The reaction was carried out according to the apparatus of Example 1. Add 445.23g of anhydrous pyridine and 124.66g of triethylamine to the flask, add 178.09g of RUSA, control the temperature at -5°C-0°C, add dropwise 173.82g of trimethylchlorosilane, control the temperature at -5°C-0°C, Control the dropwise addition time at 1h 40min. After the dropwise addition is completed, heat to reflux and keep warm for 8h. After the reaction, take out the mixture, add methanol (the amount added is 12% of the volume of the mixture) and let it stand for 2h to separate the liquids. Remove the lower layer and simply distill and heat to 50-60°C until no fractions are distilled; control the vacuum distillation pressure to 0.1 MPa until no fractions are distilled to obtain the product TFDA with a yield of 89.8% in terms of RUSA and a purity of 92.5%.

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Abstract

The invention relates to the technical field of organic synthesis, and provides a preparation method of trimethylsilyl 2-(fluorosulfonyl) difluoroacetate, which comprises the following steps: S1, adding pyridine into a dry three-neck flask connected with a constant-pressure dropping funnel and a nitrogen protection and tail gas absorption device; S2, adding 2-fluorosulfonyl difluoroacetic acid and triethylamine, and controlling the temperature; S3, dropwise adding trimethylchlorosilane, and controlling the temperature; S4, after dropwise adding is completed, heating to reflux, and carrying out heat preservation reaction; and S5, adding methanol for liquid separation, taking a lower layer, and distilling to obtain a product. Through the technical scheme, the problem of low yield of the preparation method in the prior art is solved.

Description

technical field [0001] The invention relates to the technical field of organic synthesis, in particular to a preparation method of trimethylsilyl 2-(fluorosulfonyl)difluoroacetate. Background technique [0002] Trimethylsilyl 2-(fluorosulfonyl)difluoroacetate, molecular formula: C 5 h 9 f 3 o 4 SSi, English name: Trimethylsilyl 2-(fluorosulphonyl) difluoroacetate, TFDA for short, is the precursor of difluorocarbene, used for cyclopropanation of alkenes. It can also be used in ion exchange resins, surfactants and other fields. [0003] TFDA was originally prepared by the reaction of silver salt of (fluorosulfonyl)difluoroacetic acid and trimethylsilyl iodide. On the one hand, it is difficult to obtain the reactants, and the direct purchase is expensive, and on the other hand, the reaction yield is low. In WO 2007 / 136541, hexamethyldisiloxane, trimethylchlorosilane, and fluorosulfonyl difluoroacetyl chloride were used for heating reaction, and the yield can reach 84%, but...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07F7/18
CPCC07F7/1896
Inventor 李庆占邢艳召刘鹏吴红松
Owner SHIJIAZHUANG SAN TAI CHEM CO LTD