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Method for preparing alpha-bromo-cinnamaldehyde

A bromocinnamaldehyde, preparation technology, applied in the direction of the preparation of organic compounds, carbon-based compounds, chemical instruments and methods, etc., can solve the problems of high price, difficult uniformity of reaction, high viscosity of reactants, etc., to achieve beneficial Effects of industrialized production, reduction of production cost and optimization of process conditions

Inactive Publication Date: 2013-06-19
WUHAN INSTITUTE OF TECHNOLOGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The report of this reaction α-bromocinnamaldehyde was first reported by Zinko et al. in J.Organomet, 17: 1815 (1884). The synthetic route uses glacial acetic acid as a solvent, and the elimination reaction process uses a strong base potassium carbonate. During the enlarged production, the viscosity of the reaction system is large, and the reaction is difficult to be uniform. The post-treatment process needs to use a large amount of alkali to neutralize the solvent glacial acetic acid, and a large amount of by-product acetate is generated, and the α-bromocinnamaldehyde obtained by this method has a darker color. affect product quality
At the same time, Lu Yujing mentioned in the Chinese patent publication CN1086214A that the method of using sodium carbonate instead of potassium carbonate still cannot solve the problem that the viscosity of the reactant is high and the glacial acetic acid cannot be recovered.
And Sun Mingkun etc. reported the method using carbon tetrachloride to be solvent in fine chemical industry, 7:5 (1990), and in this method, bromine addition reaction uses carbon tetrachloride to be solvent, and elimination reaction process uses 2,4-dichloride The picoline is used as the base, and because 2,4-lutidine is expensive, this method is not conducive to the cost control of the large-scale production process
In addition, Olah et al reported another method of α-bromocinnamaldehyde in J.Prakt.Chem. (1981), which uses thionyl bromide as the brominating agent, which is expensive and highly toxic , is also not conducive to industrial production

Method used

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  • Method for preparing alpha-bromo-cinnamaldehyde

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] Dissolve 13.2g (0.1mol) of cinnamaldehyde in 50ml of ethyl acetate, cool in an ice bath to 0°C, slowly add 16.0g (0.1mol) of bromine dropwise under stirring, and finish adding in about 1 hour. Stir for 15 minutes to obtain a solution of 2,3-dibromo-3-phenylpropanal, without separation, directly add 12.3g (0.15mol) of anhydrous sodium acetate, heat up to 50°C and stir for 30 minutes, then heat up to 80°C Stir at reflux for 3 hours, cool to room temperature, filter, wash the filtrate with 2×30ml water, separate the water layer, concentrate the organic layer in vacuo to remove the solvent, add 50ml petroleum ether to the residue, stir and cool to room temperature, and precipitate granular crystals. After filtering, the filter cake was washed with 25ml of petroleum ether and dried with hot air at 45°C to obtain 18.2g of the product (86.2% yield) with a melting point of 70-72°C.

Embodiment 2

[0024] Dissolve 13.2g (0.1mol) of cinnamaldehyde in 80ml of ethyl acetate, cool in an ice bath to 0°C, and slowly add 16.0g (0.1mol) of bromine dropwise under stirring for about 1 hour. Stir for 15 minutes to obtain 2,3-dibromo-3-phenylpropanal solution, without separation, directly add 25.6g (0.18mol) disodium hydrogen phosphate, heat up to 50°C and stir for 30 minutes, then heat up to 80°C Stir at ℃ for 3 hours, cool down to room temperature, filter, wash the filtrate with 2×30ml water, separate the water layer, concentrate the organic layer in vacuo to remove the solvent, add 50ml petroleum ether to the residue, stir and cool to room temperature, and precipitate granular crystals. After filtering, the filter cake was washed with 25ml of petroleum ether, and dried with hot air at 45°C to obtain 17.7g of the product (yield 83.9%), with a melting point of 70-72°C.

Embodiment 3

[0026] Dissolve 13.2g (0.1mol) of cinnamaldehyde in 50ml of ethyl formate, cool in an ice bath to 0°C, and slowly add 16.0g (0.1mol) of bromine dropwise under stirring for about 1 hour. Stir for 15 minutes to obtain a solution of 2,3-dibromo-3-phenylpropanal, without separation, directly add 13.1g (0.16mol) of anhydrous sodium acetate, heat up to 50°C and stir for 30 minutes, then heat up to 80°C Stir at ℃ for 3 hours, cool down to room temperature, filter, wash the filtrate with 2×30ml water, separate the water layer, concentrate the organic layer in vacuo to remove the solvent, add 50ml petroleum ether to the residue, stir and cool to room temperature, and precipitate granular crystals. After filtering, the filter cake was washed with 25ml of petroleum ether, and dried with hot air at 45°C to obtain 15.3g of the product (yield 72.5%), with a melting point of 70-72°C.

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Abstract

The invention relates to a method for preparing alpha-bromo-cinnamaldehyde, which comprises the following steps of: firstly, dissolving raw materials of cinnamyl aldehyde in a solvent, dripping bromine at low temperature, and stirring for 15 minutes after dripping bromine to obtain a 2,3-dibrimo-3-phenylpropanal solution, and secondly, adding weak base in the 2,3-dibrimo-3-phenylpropanal solutionobtained in the first step according to 1-4 times as much as the amount of cinnamyl aldehyde, reacting the system after raising the temperature to 50+ / -5 DEG C (the time range is given), then reacting the system after raising the temperature to 80+ / -5 DEG C (the time range is given), then cooling to the ambient temperature to filter, washing the filtrate, then concentrating to distill over the solvent, adding petroleum ether in the residue to stir and crystallize, filtering and drying by hot air to obtain the alpha-bromo-cinnamaldehyde. Compared with the prior art, the method has the advantages of selecting the solvent which can be recycled, adopting alkaline with low cost and low toxicity in the elimination reaction process, optimizing the conditions of the method, reducing the production cost, having good production cost, excellent product quality and high yield, and being beneficial to the industrialized production.

Description

technical field [0001] The invention relates to a preparation process of α-bromocinnamaldehyde. Background technique [0002] α-Bromocinnamaldehyde is a broad-spectrum high-efficiency antifungal fungicide, which is widely used in leather, textile, food and daily necessities industries. Synthesizing fungicide α-Bromocinnamaldehyde with cinnamaldehyde as raw material is currently the most direct Reaction route, this route includes two-step reactions of bromine addition and elimination, bromine addition products usually do not need to be separated, and the elimination reaction is directly carried out to obtain the product. The report of this reaction α-bromocinnamaldehyde was first reported by Zinko et al. in J.Organomet, 17: 1815 (1884). The synthetic route uses glacial acetic acid as a solvent, and the elimination reaction process uses a strong base potassium carbonate. During the enlarged production, the viscosity of the reaction system is large, and the reaction is difficu...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C47/24C07C45/65
Inventor 王凯黄婷符兆林
Owner WUHAN INSTITUTE OF TECHNOLOGY