CN106242950B - A method of preparing pyrogallic acid - Google Patents
A method of preparing pyrogallic acid Download PDFInfo
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- CN106242950B CN106242950B CN201610614008.6A CN201610614008A CN106242950B CN 106242950 B CN106242950 B CN 106242950B CN 201610614008 A CN201610614008 A CN 201610614008A CN 106242950 B CN106242950 B CN 106242950B
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/50—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by reactions decreasing the number of carbon atoms
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/09—Preparation of carboxylic acids or their salts, halides or anhydrides from carboxylic acid esters or lactones
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Abstract
The present invention relates to a kind of preparation method of organic compound, in particular to a kind of production method of pyrogallic acid；It is reasonably combined by hydrochloric acid and walnut kernel extract, effectively the tanning material in Chinese gall and Ta La powder is adequately hydrolyzed and is come, again by making gallic acid decarboxylation generate pyrogallic acid under the high temperature conditions, the present invention effectively raises product yield, so that energy consumption and production cost significantly reduce, wherein to the reasonable control of concentration of hydrochloric acid, reduce the corrosion to equipment, also it can optimize hydrolysis effect, meanwhile by the reasonably combined of hydrolyzate, has the function of synergy, improve percent hydrolysis, up to 98% or more.
Description
Technical field
The present invention relates to a kind of preparation method of organic compound, in particular to a kind of producer of pyrogallic acid
Method.
Background technique
Pyrogallic acid, i.e. pyrogallol or pyrogallol, for white or yellow needles body, relative density 1.453,
131~133 DEG C of melting range, 309 DEG C of boiling point (293 DEG C decomposition), distillation is easily aoxidized without decomposing when slow heating, soluble easily in water,
Ethyl alcohol and ether are slightly soluble in benzene, dimethylbenzene, chloroform, carbon disulfide equal solvent, strong to the irritation of skin, mucous membrane, when swallowing coke
When property gallic acid, the serious damage of alimentary canal, liver, kidney can be caused.
Pyrogallic acid is a kind of chemical reagent and industrial chemicals to serve many purposes, is widely used in chemical industry, has
The fields such as machine synthesis, printing and dyeing, analysis, food, medicine, pesticide, pyrogallic acid are a kind of important organic fine chemical industry productions
Product are mainly used for oxygen absorbent, photographic developer and heat sensitizer, radioactive element trapping agent, dye mordant, metal salt reduction
Agent, neutral plating, neoprene vulcanization and PVC polymeric kettle additive, food packaging, synthetic resin antioxidant, and certain
Field is that other products are irreplaceable, there is very big economic benefit and social benefit.
The market demand of pyrogallic acid is 600t/a or so at present, and national annual output is 200~500t/a, also nothing
Method meets the needs of market, and the primary raw material for producing pyrogallic acid is gallic acid, and gallic acid is mainly by Chinese gall, tower
The extract of drawing etc. is obtained after hydrolysis, and gallic acid generates pyrogallic acid after by thermal decarboxylation, pyrogallic acid
There are many preparation method, mainly by forestry products chemical process, obtain from gallotannins (tannin) or tower wax (tara) tannin
Pyrogallic acid is generated after by thermal decarboxylation to gallic acid, it is main at present using biological decarboxylation, normal pressure catalytic decarboxylation and decompression
Catalytic decarboxylation and microorganism be de- the methods of to complete preparation, and the technique for producing pyrogallic acid earliest is that the direct destructive distillation of gallic acid is de-
The shortcomings that carboxylic, the technique is that side reaction is more, and product yield is low, second-rate, therefore quickly by vacuum decarboxylation method and solvent decarboxylation
It method and is replaced using water by the high pressure decarboxylation method of medium；Solvent decarboxylation method there are still purifying products and difficult solvent recovery, be produced into
The disadvantages of this is high；And there are product concentrating and purifying heavy workload, the high requirements on the equipment, construction investment are biggish for high pressure decarboxylation method
Disadvantage；Since the seventies, the production technology of domestic and international focusability gallic acid makes further research and improves, Poland's exploitation
Catalytic decarboxylation technique, using organic catalysts such as first phthalein amine makes gallic acid normal pressure decarboxylation, crude product at 150~200 DEG C
It is distilled in the presence of two fourth vinegar, is then recrystallized to give qualified products with solvent, the mild reaction condition, product yield
Height, but there is solvent recovery difficulty it is big, production equipment is huge the deficiencies of；In addition it can prepare coke using chemical synthesis
Gallic acid, but since technical difficulty is big, yield is low, and engineering problem is more, is difficult to industrialize for the moment；Currently, in gallic acid
It is prepared in the method for pyrogallic acid for raw material, really realizes only decompression decarboxylation method and the normal pressure decarboxylation of industrialized production
Method, and it is more mature and universal to depressurize decarboxylation method, but have the disadvantage in that material uneven heating is even, energy consumption is high, drop
Low life of equipment, is often used catalyst in process of production, and environmental pollution is serious, in product analyze net product ratio compared with
It is low, mostly chemical pure and mild industrial products.
It is prepared in conclusion production pyrogallic acid mainly carries out decarboxylation processing as raw material using gallic acid,
But due to decarboxylation method used unreasonable, lead to the problems such as product yield is low, and energy consumption is high, therefore select scientific and reasonable mode
Pyrogallic acid is prepared, product yield is improved, meets the needs of existing market, with very big economic benefit and society's effect
Benefit, while the technical field for also preparing pyrogallic acid for gallic acid deep processing provides a kind of new approaches.
Summary of the invention
The present invention is in order to solve the above technical problems, provide a kind of method for preparing pyrogallic acid.
It is realized particular by following technical scheme:
A method of preparing pyrogallic acid, comprising the following steps:
(1) gallic acid is prepared, comprising the following steps:
A, prepare hydrolyzate: first by walnut meat powder, 55~65% Organic Alcohols are mixed by 1: 3~5 weight ratio, 75~90
At DEG C stir 120~200min, after being cooled to 20~25 DEG C, stand 12~20h, filtering, by filtrate at 60~65 DEG C vacuum
After 30~50min is concentrated, ethylene glycol extraction is added, extract liquor and hydrochloric acid are mixed by 0.3~0.5: 1 weight ratio, wherein salt
Acid concentration is 3.5~4.2mol/ml；
B, it hydrolyzes: the crushing of tannin biomass will be contained, 2~3 times of water of crushed material weight is added, boil 25 at 85~90 DEG C
~40min, filtering repeat 2~3 aforesaid operations, and No. 3~4 extracting solutions are mixed, 1/3 body is concentrated at 90~100 DEG C
Product, is cooled to 60~70 DEG C, and concentrate and hydrolyzate are mixed by 0.8~1.2: 0.2~0.5 weight ratio, stand 6~8h,
The mixture of gallic acid must be contained；
(2) it prepares pyrogallic acid: the mixture of step b is added in enamel still, addition mixture weight 0.8~
1.2% active carbon is heated with stirring to boiling, send to filter, filtrate returns in enamel still, continues to be heated to 180~220
DEG C, 2~4h is stirred, is cooled to 20~25 DEG C, organic solvent extraction is added, pyrogallic acid crude product is made, it is crystallized, it is dry
?.
Further, the vacuum compression, vacuum system pressure are 0.05~0.07Mpa.
Further, the biomass containing tannin is that Chinese gall and Ta La powder are mixed by 0.3~0.5: 0.6 weight ratio.
Further, the organic solvent, be 100% butanol, n-octyl amine and methanol by 1.3~1.5: 0.7~0.9:
0.01~0.03 volume ratio mixing.
Further, the extraction, temperature are 26~31 DEG C, and the time is 12~15min.
In conclusion the beneficial effects of the present invention are: the object that can decompose tannin is extracted in alcohols using walnut kernel
Tanning material in Chinese gall and Ta La powder effectively can be hydrolyzed adequately and be come, be disappeared by the rational proportion with hydrochloric acid by matter
Consuming index and production cost significantly reduces, and after obtaining the mixture of gallic acid and glucose, suitable active carbon is added, has
Have it is preferable can catalytic, can be used as carrier-mediated, and the decolorization to grease, purer gallic acid can be obtained,
Under the high temperature conditions, so that gallic acid carries out decarboxylation, then by the extraction of organic solvent, pyrogallic acid is obtained.
The present invention passes through the scientific and reasonable proportion of Chinese gall and Ta La powder, improves tannin content in raw material, ensure that
The ultimate yield of pyrogallic acid passes through the rational proportion of walnut kernel, Organic Alcohol and hydrochloric acid in hydrolyzate, wherein to hydrochloric acid
The reasonable control of concentration, reduces the corrosion to equipment, can also make to optimize hydrolysis effect, make full use of walnut kernel in Organic Alcohol
The effective component of hydrolysis tanning material can be extracted, then is subject to hydrochloric acid to the hydrolysis of tannin, so that the hydrolyzate tool prepared
There is synergy, improves percent hydrolysis, up to 98% or more.
Preparation method is further described below:
1, hydrochloric acid plays the role of one and is equivalent to catalyst during tannin hydrolyzes, and is not that its concentration is got over
Greatly, catalytic effect is better；The present invention selects various concentration, tests the percent hydrolysis of tanning material, the results are shown in Table 1:
Table 1
| Concentration of hydrochloric acid mol/ml | 2 | 3 | 4.5 |
| Percent hydrolysis % | 65 | 78 | 61 |
2, on the concentration of hydrochloric acid of table 1, after adding extract of the walnut kernel in Organic Alcohol, pass through the conjunction with hydrochloric acid
Reason collocation, tests the percent hydrolysis of tanning material, the results are shown in Table 2:
Table 2
| Hydrochloric acid: extract | 1∶0.2 | 1∶0.3 | 1∶0.4 | 1∶0.5 | 1∶0.6 |
| Percent hydrolysis % | 91 | 98.5 | 99 | 98.7 | 94 |
3, it is extracted using the focusability gallic acid of organic solvent that the present invention prepares, extraction yield is counted, with
As a control group, the results are shown in Table 3 for conventional extraction process:
Table 3
| Compare object | Extracting process of the present invention | Conventional extraction process |
| Extraction yield % | 93.6 | 85.4 |
4, product quality analysis data:
Appearance: white or yellowish, glossy powder；Fusing point: 131~133 DEG C；Specific gravity: 1.44~1.46；Water dissolution examination
It tests: being lauched and dissolved successfully at 15~20 DEG C；Chloride (C1- >) :≤3.1ppm；Sulfate (SO42-): it is not detected；It is dry to lose
Weight: 0.52%；Gallic acid: it is not detected；Content (butt): 99.30%.
Specific embodiment
Specific embodiments of the present invention will be described in further detail below, but the invention is not limited to these realities
Mode is applied, it is claimed to still fall within the claims in the present invention for any improvement or replacement on the present embodiment essence spirit
Range.
Embodiment 1
A method of preparing pyrogallic acid, comprising the following steps:
(1) gallic acid is prepared, comprising the following steps:
A, prepare hydrolyzate: first by walnut meat powder, 55% Organic Alcohol is mixed by 1: 3 weight ratio, is stirred at 75 DEG C
120min after being cooled to 20 DEG C, stands 12h, and after filtrate is concentrated in vacuo 30min at 60 DEG C, ethylene glycol extraction is added in filtering
It takes, extract liquor and hydrochloric acid is mixed by 0.3: 1 weight ratio, wherein concentration of hydrochloric acid 3.5mol/ml；
B, it hydrolyzes: the crushing of tannin biomass will be contained, 2 times of water of crushed material weight is added, in 85 DEG C of tanning 25min, mistake
Filter, is repeated twice aforesaid operations, and No. 3 extracting solutions are mixed, 1/3 volume is concentrated at 90 DEG C, is cooled to 60 DEG C, will be dense
Contracting liquid and hydrolyzate are mixed by 0.8: 0.2 weight ratio, are stood 6~8h, are obtained the mixture containing gallic acid；
(2) it prepares pyrogallic acid: the mixture of step b is added in enamel still, mixture weight 0.8% is added
Active carbon is heated with stirring to boiling, send to filter, and filtrate returns in enamel still, continues to be heated to 180 DEG C, stirs 2h, cooling
To 20 DEG C, organic solvent extraction is added, pyrogallic acid crude product is made, it is crystallized, it is dry.
The vacuum compression, vacuum system pressure are 0.05Mpa.
The biomass containing tannin is that Chinese gall and Ta La powder are mixed by 0.3: 0.6 weight ratio.
The organic solvent is that 100% butanol, n-octyl amine and methanol is mixed by 1.3: 0.7: 0.01 volume ratio.
The extraction, temperature are 26 DEG C, time 12min.
Embodiment 2
A method of preparing pyrogallic acid, comprising the following steps:
(1) gallic acid is prepared, comprising the following steps:
A, prepare hydrolyzate: first by walnut meat powder, 65% Organic Alcohol is mixed by 1: 5 weight ratio, is stirred at 90 DEG C
200min after being cooled to 25 DEG C, stands 20h, and after filtrate is concentrated in vacuo 50min at 65 DEG C, ethylene glycol extraction is added in filtering
It takes, extract liquor and hydrochloric acid is mixed by 0.5: 1 weight ratio, wherein concentration of hydrochloric acid 4.2mol/ml；
B, it hydrolyzes: the crushing of tannin biomass will be contained, 3 times of water of crushed material weight is added, in 90 DEG C of tanning 40min, mistake
Filter, repeats 3 aforesaid operations, and No. 4 extracting solutions are mixed, 1/3 volume is concentrated at 100 DEG C, is cooled to 70 DEG C, will be dense
Contracting liquid and hydrolyzate are mixed by 1.2: 0.5 weight ratio, are stood 8h, are obtained the mixture containing gallic acid；
(2) it prepares pyrogallic acid: the mixture of step b is added in enamel still, mixture weight 1.2% is added
Active carbon is heated with stirring to boiling, send to filter, and filtrate returns in enamel still, continues to be heated to 220 DEG C, stirs 4h, cooling
To 25 DEG C, organic solvent extraction is added, pyrogallic acid crude product is made, it is crystallized, it is dry.
The vacuum compression, vacuum system pressure are 0.07Mpa.
The biomass containing tannin is that Chinese gall and Ta La powder are mixed by 0.5: 0.6 weight ratio.
The organic solvent is that 100% butanol, n-octyl amine and methanol is mixed by 1.5: 0.9: 0.03 volume ratio.
The extraction, temperature are 31 DEG C, time 15min.
Embodiment 3
A method of preparing pyrogallic acid, comprising the following steps:
(1) gallic acid is prepared, comprising the following steps:
A, prepare hydrolyzate: first by walnut meat powder, 60% Organic Alcohol is mixed by 1: 4 weight ratio, is stirred at 85 DEG C
160min after being cooled to 22 DEG C, stands 15h, and after filtrate is concentrated in vacuo 40min at 62 DEG C, ethylene glycol extraction is added in filtering
It takes, extract liquor and hydrochloric acid is mixed by 0.4: 1 weight ratio, wherein concentration of hydrochloric acid 4mol/ml；
B, it hydrolyzes: the crushing of tannin biomass will be contained, 2.5 times of water of crushed material weight is added, in 87 DEG C of tanning 35min,
Filtering, is repeated 2 times aforesaid operations, and No. 3 extracting solutions are mixed, 1/3 volume is concentrated at 95 DEG C, is cooled to 65 DEG C, will be dense
Contracting liquid and hydrolyzate are mixed by 1: 0.3 weight ratio, are stood 7h, are obtained the mixture containing gallic acid；
(2) it prepares pyrogallic acid: the mixture of step b is added in enamel still, the work of mixture weight 1% is added
Property charcoal, be heated with stirring to boiling, send to filter, filtrate returns in enamel still, continues to be heated to 200 DEG C, stirs 3h, is cooled to
23 DEG C, organic solvent extraction is added, pyrogallic acid crude product is made, it is crystallized, it is dry.
The vacuum compression, vacuum system pressure are 0.06Mpa.
The biomass containing tannin is that Chinese gall and Ta La powder are mixed by 0.4: 0.6 weight ratio.
The organic solvent is that 100% butanol, n-octyl amine and methanol is mixed by 1.4: 0.8: 0.02 volume ratio.
The extraction, temperature are 28 DEG C, time 13min.
Claims (4)
1. a kind of method for preparing pyrogallic acid, which comprises the following steps:
(1) gallic acid is prepared, comprising the following steps:
A, prepare hydrolyzate: first by walnut meat powder, 55 ~ 65% Organic Alcohols are mixed by the weight ratio of 1:3 ~ 5, are stirred at 75 ~ 90 DEG C
120 ~ 200min is mixed, after being cooled to 20 ~ 25 DEG C, stands 12 ~ 20h, filtering, filtrate is concentrated in vacuo to 30 at 60 ~ 65 DEG C ~
After 50min, ethylene glycol extraction is added, extract liquor and hydrochloric acid are mixed by the weight ratio of 0.3 ~ 0.5:1, wherein concentration of hydrochloric acid is
3.5~4.2mol/ml；
B, hydrolyze: will contain tannin biomass crushing, be added crushed material weight 2 ~ 3 times of water, 85 ~ 90 DEG C boil 25 ~
40min, filtering repeat 2 ~ 3 aforesaid operations, and No. 3 ~ 4 extracting solutions are mixed, 1/3 volume is concentrated at 90 ~ 100 DEG C, cold
But to 60 ~ 70 DEG C, concentrate and hydrolyzate is mixed by the weight ratio of 0.8 ~ 1.2:0.2 ~ 0.5,6 ~ 8h is stood, obtains containing galla turcica
The mixture of acid；
(2) it prepares pyrogallic acid: the mixture of step b is added in enamel still, mixture weight 0.8 ~ 1.2% is added
Active carbon is heated with stirring to boiling, send to filter, and filtrate returns in enamel still, continues to be heated to 180 ~ 220 DEG C, and stirring 2 ~
4h is cooled to 20 ~ 25 DEG C, and organic solvent extraction is added, and pyrogallic acid crude product is made, crystallized, dry；
The organic solvent, be 100% butanol, n-octyl amine and methanol by 1.3 ~ 1.5:0.7 ~ 0.9:0.01 ~ 0.03 body
Product is than mixing.
2. the method for preparing pyrogallic acid as described in claim 1, which is characterized in that the vacuum concentration is true
Empty system pressure is 0.05 ~ 0.07MP a.
3. the method for preparing pyrogallic acid as described in claim 1, which is characterized in that the biomass containing tannin,
It is that Chinese gall and Ta La powder are mixed by the weight ratio of 0.3 ~ 0.5:0.6.
4. as described in claim 1 prepare pyrogallic acid method, which is characterized in that the extraction, temperature be 26 ~
31 DEG C, the time is 12 ~ 15min.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101143806A (en) * | 2007-09-30 | 2008-03-19 | 浙江大学 | Method for preparing pyrogallic acid from gallic acid in high temperature liquid state water medium by catalyst-free decarboxylating |
| CN102816062A (en) * | 2012-09-10 | 2012-12-12 | 浙江大学 | Method for preparing gallic acid by hydrochloric acid catalytic hydrolysis of tannin containing biomass in high temperature liquid water |
| CN102845572A (en) * | 2012-08-30 | 2013-01-02 | 陈朝银 | Walnut tea based on walnut kernel polyphenol and preparation of drink thereof |
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2016
- 2016-07-30 CN CN201610614008.6A patent/CN106242950B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101143806A (en) * | 2007-09-30 | 2008-03-19 | 浙江大学 | Method for preparing pyrogallic acid from gallic acid in high temperature liquid state water medium by catalyst-free decarboxylating |
| CN102845572A (en) * | 2012-08-30 | 2013-01-02 | 陈朝银 | Walnut tea based on walnut kernel polyphenol and preparation of drink thereof |
| CN102816062A (en) * | 2012-09-10 | 2012-12-12 | 浙江大学 | Method for preparing gallic acid by hydrochloric acid catalytic hydrolysis of tannin containing biomass in high temperature liquid water |
Non-Patent Citations (1)
| Title |
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| 核桃饼粕多酚纯化工艺及其抗氧化活性的研究;梁杏 等;《中国酿造》;20151231;第34卷(第4期);第55页第1段和第56页第1.3.1、1.3.4部分 * |
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