Pyrogallic acid production method

A technology of pyrogallic acid and production method, which is applied in chemical instruments and methods, preparation of organic compounds, organic chemistry, etc., can solve the problems of low quality product rate, long time, main decarboxylation reaction temperature, etc., and achieves short process time , the effect of mild reaction temperature

Active Publication Date: 2013-12-18
湖北天新生物科技有限责任公司
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AI Technical Summary

Problems solved by technology

[0002] At present, gallic acid is heated and melted in a container, sublimed and decarboxylated at a temperature of 180°C-220°C to obtain pyrogallic acid. The h

Method used

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Examples

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Embodiment 1

[0007] A production method of pyrogallic acid is to mix accurately measured 600 kg of gallic acid and 12 kg of p-nitroaniline in a reaction kettle, slowly raise the temperature to 140 ° C, and transfer the material to the sublimation stage after it is basically melted. In the kettle, let it stand for 30 minutes, turn on the vacuum system, slowly raise the temperature, control the temperature at 130°C-150°C, collect the sublimation products poured out into the collection kettle until no sublimation products are poured out, and the sublimation products poured out are For pyrogallic acid.

[0008] At the end of the reaction, pyrogallic acid was graded according to the quality standard, and classified into analytically pure pyrogallic acid (accounting for about 30%), chemically pure pyrogallic acid (accounting for about 50%) and industrial pure pyrogallic acid ( About 20%) crushed and sieved, analyzed and packaged to obtain the finished product of pyrogallic acid.

[0009] In Exa...

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Abstract

The invention provides a pyrogallic acid production method. The pyrogallic acid production method comprises the following steps of: mixing gallic acid and paranitroaniline in a mass ratio of 100: (2-2.5), putting the mixture in a reaction kettle, slowly heating to 140 DEG C till the mixture is melted completely; transferring the molten material to a subliming kettle, standing still for 20-30 minutes, opening a vacuum system, heating the subliming kettle, slowly warming up, controlling the temperature at 130 DEG C to 150 DEG C, and collecting a distilled subliming product till no subliming product is distilled, and thus the distilled subliming product is pyrogallic acid. The pyrogallic acid production method has the advantages that a special decarboxylation reagent, namely, the paranitroaniline, is selected, so that the gallic acid is subjected to a decarboxylation reaction at the temperature of 130-150 DEG C so as to generate the pyrogallic acid, the conversion rate of the gallic acid reaches above 98%, the yield of the high-quality product (analytical pure and chemical pure) reaches above 80%; and the reaction temperature in the method is mild, and the whole working procedure time is short.

Description

technical field [0001] The invention relates to a method for preparing organic compounds, in particular to a method for producing pyrogallic acid. Background technique [0002] At present, gallic acid is heated and melted in a container, sublimed and decarboxylated at a temperature of 180°C-220°C to obtain pyrogallic acid, the high-quality product rate (chemically pure and above) is about 30%, and the decarboxylation reaction temperature is mainly , Long time, low quality product rate. Contents of the invention [0003] The purpose of the present invention is to provide a production method of pyrogallic acid, which is characterized by mild reaction temperature, short process time, high conversion rate and high-quality product rate. [0004] In order to achieve the goal, the technical solution of the present invention is: a production method of pyrogallic acid, which is to mix gallic acid and p-nitroaniline according to the ratio of 100:2 to 2.5 in mass ratio, place in a ...

Claims

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Application Information

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IPC IPC(8): C07C39/10C07C37/50
Inventor 毛义华郭祥洲周国宗潘成名
Owner 湖北天新生物科技有限责任公司
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