A kind of preparation method of 1-bromoethyl acetate

A technology of bromoethyl acetate and vinyl acetate, which is applied in the field of preparation of 1-bromoethyl acetate, can solve the problems of uncontrollable reaction, uncontrollable reaction, and increased impurities, so as to avoid production equipment and operation The effect of high protection requirements, mild reaction conditions, and easy separation and recovery

Active Publication Date: 2019-01-29
GUANGDONG LIGUO PHARMACY
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Problems solved by technology

[0004] However, in the current preparation process, the reaction raw material acetyl bromide is unstable; the low boiling point of acetaldehyde makes the reaction difficult to control, which brings difficulties to industrial production, and acetaldehyde is carcinogenic; when hydrogen bromide is used as a reactant, hydrogen bromide It is the gas that makes the reaction difficult to control, the material ratio is not easy to determine, and the utilization rate of the reactants is low; the hydrogen bromide is dissolved in a solvent, and the hydrobromic acid solution with a certain concentration is reacted with vinyl acetate to synthesize 1-bromoethyl acetate , although the problem of hydrogen bromide quantification in the reaction has been solved, the step of dissolving gaseous hydrogen bromide in a solvent is still unavoidable, and the industrial application still cannot avoid the limitations of difficult control, large pollution, and harsh operating conditions
Using zinc chloride as a catalyst, zinc chloride is very easy to absorb water and form agglomerates, resulting in a decrease in catalytic efficiency, an increase in impurities, and the introduction of zinc ions, heavy metal pollution, low yield, and low purity
Replacing zinc chloride with a catalyst with a naphthalene ring structure, although the yield has been improved to a certain extent, the catalyst with a naphthalene ring structure is more difficult to remove than the zinc salt catalyst, and the product purity is not high
When the catalyst is not used for the reaction, the yield of the product is low, resulting in a large degree of waste

Method used

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  • A kind of preparation method of 1-bromoethyl acetate
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  • A kind of preparation method of 1-bromoethyl acetate

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preparation example Construction

[0045] The preparation of nano ferric oxide:

[0046] 1) Divalent iron salt (FeSO 4 ·7H 2 O) and ferric salt (FeCl 3 ·6H 2 O) after mixing according to the mol ratio of 2:3, add pure water, make the iron salt total concentration be 0.6mol / L;

[0047] 2) Adjust the temperature to 45°C, and slowly add ammonia water while stirring until the pH of the solution is 9;

[0048] 3) Add surfactant sodium dodecylbenzene sulfonate and stir vigorously for 60 minutes, wherein the amount of surfactant is 10% of the amount of ferrous salt;

[0049] 4) After settling with a magnet, let it stand for 5 minutes, take the precipitate, and wash the precipitate alternately with pure water and absolute ethanol until the pH of the washing water is neutral;

[0050] 5) Dry the precipitate in an oven for 5 hours to obtain nanometer ferric oxide.

[0051] The prepared nano iron ferric oxide has superparamagnetism and water insolubility, and the particle diameter is 250-300nm.

Embodiment 1

[0053] Add 40.6 mL of pure water and 0.4 g of nanometer ferric oxide to a reaction flask equipped with a mechanical stirrer, keep the temperature at 6°C, add 145 mL of silicon tetrabromide after stirring for 3 minutes, and slowly add 377 mL of vinyl acetate after stirring for 5 minutes, Adjust the temperature to 15°C, and finish the reaction after a period of reaction; use a magnet to separate the nano-ferric oxide from the mixed solution after reaction, and then pass the mixed solution through a 0.22 μm organic filter membrane to remove solid impurities; cool the mixed solution to Keep at 4°C, add 100mL of extractant to it, stir for 15min, add 30mL of pure water, stir for 5min, let stand for 5min, take the organic phase, add 40mL of pure water and stir for 5min, let stand for 5min, take the organic phase for vacuum distillation, remove Distillation, that is, the product 1-bromoethyl acetate. Wherein the extractant is a mixture of dichloromethane and chloroform with a volume r...

Embodiment 2

[0057] Add 54.0mL of pure water and 0.6g of nanometer ferric oxide to a reaction flask equipped with a mechanical stirrer, keep the temperature at 6°C, add 150mL of silicon tetrabromide after stirring for 5 minutes, slowly add vinyl acetate after stirring for 5 minutes, and The temperature was adjusted to 15°C, and the reaction was completed after 40 minutes of reaction; the nano-ferric oxide was separated from the reacted mixed solution with a magnet, and then the mixed solution was passed through a 0.22 μm organic filter membrane to remove solid impurities; the mixed solution was cooled to 4°C and Keep, add extractant 100mL to it, stir for 15min, add pure water 30mL, stir for 5min, let stand for 5min, take organic phase, add pure water 40mL and stir for 5min, let stand for 5min, take organic phase and distill under reduced pressure, remove distillate, namely The product 1-bromoethyl acetate was obtained. Wherein the extractant is a mixture of dichloromethane and chloroform w...

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Abstract

The invention belongs to the field of chemical synthesis, and relates to a preparation method of 1-bromoethyl acetate. According to the method, nano Fe3O4 is used as a catalyst, and the target productis generated by enabling silicon tetrabromide and vinyl acetate to react in a water solution. The process conditions of the method are mild and easy to control, the catalyst is high in activity and easy to recover, and product yield and purity are high.

Description

technical field [0001] The invention belongs to the field of chemical synthesis, and in particular relates to a preparation method of 1-bromoethyl acetate. Background technique [0002] Bromoacetate is an important fine chemical raw material and intermediate, widely used in the synthesis of various chemical raw materials such as pesticides, medicines, dyes and polymers. Studies have shown that the bromine and hydroxyl groups of the bifunctional compound bromoalcohol have high activity, but they are unstable under alkaline conditions. The lone pair of electrons on the hydroxyl group can easily attack the bromine element and form ether, resulting in a decrease in synthesis efficiency. However, bromoacetate compounds can deesterify and release hydroxyl groups under certain conditions, and play a role in temporarily protecting the hydroxyl functional group, thereby avoiding the occurrence of side reactions. Therefore, the synthesis of bromoacetate has become a research hotspot i...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C67/307C07C69/63
CPCC07C67/307C07C69/63
Inventor 曾建江王宝许伟龙廖庆番王雄强陈开明
Owner GUANGDONG LIGUO PHARMACY
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