A kind of preparation method of 2,3-dimethoxybenzaldehyde

A technology of dimethoxybenzaldehyde and bromobenzaldehyde is applied in the preparation of pharmaceutical intermediates and in the field of preparation of 2,3-dimethoxybenzaldehyde, and can solve the problems of environmental pollution, high process cost and high toxicity. To achieve the effect of reducing environmental pollution, high product quality and easy operation

Inactive Publication Date: 2015-09-09
HEBEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In view of the above-mentioned problems of high process cost, environmental pollution, high toxicity and unsuitable for pharmaceutical intermediates, we have developed a new process route with simple process and easy to realize industrial production

Method used

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  • A kind of preparation method of 2,3-dimethoxybenzaldehyde
  • A kind of preparation method of 2,3-dimethoxybenzaldehyde
  • A kind of preparation method of 2,3-dimethoxybenzaldehyde

Examples

Experimental program
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Effect test

Embodiment 1

[0019] In a 250mL three-necked flask, stir magnetically, put 5.10g (0.03mol) of o-bromophenol, 1.78g (0.06mol) of paraformaldehyde, 5.50g (0.06mol) of anhydrous magnesium chloride, 5.85g (0.06mol) of triethylamine, toluene 60mL, reacted at 100°C for 6h. Cool to 50°C and add 10% hydrochloric acid to adjust the pH to 2-3, separate the liquid with a separatory funnel, dry the organic phase (upper layer) with anhydrous sodium sulfate until the liquid is clear without water drops, remove sodium sulfate by filtration, and distill After the solvent in the filtrate, distill under reduced pressure under 10mmHg pressure, collect 5.50g of fractions at 104~106°C, analyze as 2-hydroxyl-3-bromobenzaldehyde, and test the purity by gas chromatography with a purity of more than 99% (the same as in the following examples), Yield 92.9%.

Embodiment 2

[0021] In a 250mL three-necked flask, stir magnetically, put 5.19g (0.03mol) of o-bromophenol, 2.65g (0.09mol) of paraformaldehyde, 5.50g (0.06mol) of anhydrous magnesium chloride, 5.80g (0.06mol) of triethylamine, toluene 50mL, react at 100°C for 6h. Cool to 50°C and add 10% sulfuric acid to adjust the pH to 2-3, separate the liquid with a separatory funnel, dry the organic phase with anhydrous sodium sulfate, filter to remove sodium sulfate, distill off the solvent in the filtrate, and reduce it under a pressure of 10mmHg. Pressure distillation, collecting fractions at 104-106°C, yielded 5.78 g of 2-hydroxy-3-bromobenzaldehyde, with a yield of 94.6%.

Embodiment 3

[0023] In a 100mL three-neck flask, stir magnetically, put 1.70g (0.01mol) of o-bromophenol, 1.18g (0.04mol) of paraformaldehyde, 1.91g (0.02mol) of anhydrous magnesium chloride, 2.02g (0.02mol) of triethylamine, toluene 30mL, reacted at 100°C for 6h. Cool to 50°C and add 10% hydrochloric acid to adjust the pH to 2-3, separate the liquid with a separatory funnel, dry the organic phase with anhydrous sodium sulfate, filter to remove sodium sulfate, distill off the solvent in the filtrate, and reduce it under a pressure of 10mmHg. Pressure distillation, collecting fractions at 104-106°C, yielded 1.87 g of 2-hydroxy-3-bromobenzaldehyde with a yield of 97.2%.

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Abstract

The invention discloses a preparation method of 2,3-dimethoxy benzaldehyde. The preparation method comprises the steps of firstly preparing 3-bromine-2-hydroxy benzaldehyde by using formylation reaction of o-bromophenol, and further enabling o-bromophenol to react with sodium methoxide and DMC (dimethyl carbonate) to prepare 2,3-dimethoxy benzaldehyde. The preparation method disclosed by the invention combines methoxylation of bromine and etherification of hydroxyl; DMC is used as a methylation reagent for the etherification of hydroxyl, so that the use of toxic dimethyl sulfate is avoided, and harsh reaction conditions of taking DMC as the methylation reagent, using high temperature, high pressure and the like in the past are also avoided; the preparation method is simple and convenient in operation, and all solvents used in the preparation method can be recycled, so that the reaction cost is reduced, and the environment pollution is reduced.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and relates to the preparation of a pharmaceutical intermediate, in particular to a preparation method of 2,3-dimethoxybenzaldehyde. Background technique [0002] 2,3-Dimethoxybenzaldehyde is an important pharmaceutical intermediate, mainly used in the synthesis of berberine. [0003] At present, the production technology of 2,3-dimethoxybenzaldehyde is mainly obtained by reacting 2-methoxyl-3-hydroxybenzaldehyde with dimethyl sulfate (Chemistry and Physics of Lipids, 2002:120(1-2 ), 101-108). However, 2-methoxy-3-hydroxybenzaldehyde is expensive, and dimethyl sulfate is highly toxic and seriously pollutes the environment. The prepared 2,3-dimethoxybenzaldehyde is not suitable as a pharmaceutical intermediate. The literature reports the preparation of 2,3-dimethoxybenzaldehyde by reacting with methyl iodide, but the cost is high and the utilization rate of atoms is low (Synthetic Comm...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C47/575C07C45/64
CPCC07C45/45C07C45/64C07C47/575C07C47/565
Inventor 王家喜宋沙沙李云庆
Owner HEBEI UNIV OF TECH
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