CN104513199A - Preparation method for 4-amino-3,6-dichloropyridine-2-carboxylate - Google Patents
Preparation method for 4-amino-3,6-dichloropyridine-2-carboxylate Download PDFInfo
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- CN104513199A CN104513199A CN201410828311.7A CN201410828311A CN104513199A CN 104513199 A CN104513199 A CN 104513199A CN 201410828311 A CN201410828311 A CN 201410828311A CN 104513199 A CN104513199 A CN 104513199A
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- dichloropyridine
- amino
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- alkali
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
- C07D213/04—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D213/60—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D213/78—Carbon atoms having three bonds to hetero atoms, with at the most one bond to halogen, e.g. ester or nitrile radicals
- C07D213/79—Acids; Esters
- C07D213/803—Processes of preparation
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
- C07D213/04—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D213/60—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D213/78—Carbon atoms having three bonds to hetero atoms, with at the most one bond to halogen, e.g. ester or nitrile radicals
- C07D213/79—Acids; Esters
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Pyridine Compounds (AREA)
Abstract
The invention discloses a preparation method for 4-amino-3,6-dichloropyridine-2-carboxylate. The preparation method comprises the steps: performing a salt forming reaction on 4-amino-3,6-dichloropyridine-2-carboxylic acid and alkali in an alcohol type solvent at the temperature of 60-80 DEG C, and performing crystallization and drying to obtain 4-amino-3,6-dichloropyridine-2-carboxylate, wherein the alcohol type solvent is a low-grade alcohol solvent, and the alkali is an alkali metal hydroxide. By adoption of the alcohol solvent, the reaction is more full, and degrading and side effects of 4-amino-3,6-dichloropyridine-2-carboxylic acid are also reduced, so that the yield and the content of 4-amino-3,6-dichloropyridine-2-carboxylate are increased, the whole reaction temperature and the recycling distillation temperature are reduced, and the energy consumption is greatly reduced.
Description
Technical field
The invention belongs to medical compounds field, be specifically related to the preparation method of amino-3, the 6-dichloropyridine-2-carboxylate salts of a kind of 4-.
Background technology
Amino-3, the 6-dichloropyridine-2-carboxylic acids of 4-are a kind of pyridine carboxylic acid class new herbicides, English general by name: aminopyralid.This weedicide can be widely used in the weed control of mountain region, grassland, planting site and bare place, and existing just studied Application and Development is in rape and cereal crop field management of weeds.This compounds for mammalian per os, through skin LD
50all be greater than 5000mg/kg, belong to micro-toxicity rank.This compound is to skin without excitatory, and without sensitization, and to Mammals without teratogenesis, mutagenesis, carcinogenesis, Endocrine and reproduction have no side effect.Show through environmental organism test-results, the acute and chronic toxicity of this compounds for mammalian, birds, fish, aquatic invertebrate is low toxicity.
This melting point compound 163.5 DEG C.Vapour pressure: 9.52*10
-9pa (20 DEG C.Water-soluble is (pH7.0) 2.48g/L (18 DEG C).This compound lasting period is long, can be used for preventing and kill off grassplot annual careless as Rheum obtusifolia Linn., curled dock, creeping thistle, gentle thistle, nettle, crawl leaf buttercup, taraxacum and chickweed with perennial broadleaf, has fine selectivity simultaneously.This compound has a weakness to be not easily degrade in soil, easily produces poisoning, so be also only limitted to for bare place or the weeding of pasture, grassland at present to succession crop.According to this situation, amino for 4--3,6-dichloropyridine-2-carboxylic acids are prepared salify, can improve water-soluble, accelerate the degraded of compound at occurring in nature, the biological activity of amino-3, the 6-dichloropyridine-2-carboxylate salts of 4-is stronger simultaneously, and herbicidal effect is followed.The synthesis of amino-3, the 6-dichloropyridine-2-carboxylate salts of general 4-is all that amino-3, the 6-dichloropyridine-2-carboxylic acids of 4-add corresponding alkali in water, filter, dehydration, then oven dry obtains corresponding salt, this technique uses water to make solvent, although solvent cost is low, dehydration temperaturre is high, system viscosity is large, and water is difficult to de-clean, 4-amino-3,6-dichloropyridine-2-carboxylic acid easily decomposes in this system, and amino-3, the 6-dichloropyridine-2-carboxylate salt yields of 4-of gained are low, content is low, and impurity is many.
Summary of the invention
The object of this invention is to provide the preparation method of amino-3, the 6-dichloropyridine-2-carboxylate salts of a kind of 4-, the shortcomings such as existing method yield is low to overcome, poor product quality, long reaction time.
Object of the present invention can be reached by following measures:
The preparation method of amino-3, the 6-dichloropyridine-2-carboxylate salts of a kind of 4-: amino-3, the 6-dichloropyridine-2-carboxylic bronsted lowry acids and bases bronsted lowries of 4-carry out salt-forming reaction in alcoholic solvent at 60 ~ 80 DEG C, crystallization after reaction, drying, obtains 4-amino-3,6-dichloropyridine-2-carboxylate salt; Described alcoholic solvent is lower alcohols solvent, and described alkali is alkali metal hydroxide.
Lower alcohols solvent in the present invention refers to the alcoholic solvent of C1 ~ 4, preferably uses methyl alcohol or ethanol.The solvent that the present invention selects reduces the viscosity of reaction system, under mutual coordinated between each raw material, make 4-amino-3,6-dichloropyridine-2-carboxylic acid and alkali reaction more abundant, and reduce the difficulty reclaiming distillation, also reduce the temperature of reaction, decrease 4-amino-3, the degraded of 6-dichloropyridine-2-carboxylic acid, saves energy consumption.The consumption of alcoholic solvent in reaction system is generally 0.6 ~ 5 times of amino-3, the 6-dichloropyridine-2-carboxylic acid quality of 4-, preferably 1 ~ 3 times.
Salt-forming reaction temperature is 60 ~ 110 DEG C, more preferably 60 ~ 80 DEG C, most preferably carries out under reflux.
After salt-forming reaction, can the solvent of underpressure distillation removing 60% ~ 100%, preferably remove the solvent of 70% ~ 95%, then cooling crystallization, dry, obtain amino-3, the 6-dichloropyridine-2-carboxylate salts of corresponding 4-.
The alkali used in the present invention preferably adopts sodium hydroxide or potassium hydroxide.Mol ratio 1:0.5 ~ 1.5 of amino-3, the 6-dichloropyridine-2-carboxylic acids of 4-and alkali, preferred 1:1 ~ 1.2.
The present invention adopts specific alcohol to be solvent, under the cooperation of other conditions, not only make reaction more abundant, also reduce 4-amino-3, the degraded of 6-dichloropyridine-2-carboxylic acid and the generation of side reaction, improve yield and the content of 4-amino-3,6-dichloropyridine-2-carboxylate salt, and reduce W-response temperature and reclaim distillation temperature, save a large amount of energy consumption.
Embodiment
Embodiment 1
In reaction flask, first add 400mL methyl alcohol, under stirring, add 4-amino-3,6-dichloropyridine-2-carboxylic acid wet product (folding hundred) 200g and 45g sodium hydroxide, temperature rising reflux, is incubated 2 hours, underpressure distillation under reflux, steam methyl alcohol, when steaming methyl alcohol and reaching 300 ~ 350ml, stop distillation, pour out material, crystallisation by cooling in dish, place after 24 hours, dry, obtain 4-amino-3,6-dichloropyridine-2-carboxylic acid sodium salt 230.8g, mass content 93.2.0%, yield 97.2%.
Embodiment 2
In reaction flask, first add 500mL methyl alcohol, under stirring, add 4-amino-3,6-dichloropyridine-2-carboxylic acid wet product (folding hundred) 300g and 90g potassium hydroxide, temperature rising reflux, is incubated 2 hours, underpressure distillation under reflux, steam methyl alcohol, when steaming methyl alcohol and reaching 350 ~ 400ml, stop distillation, pour out material, crystallisation by cooling in dish, place after 24 hours, dry, obtain 4-amino-3,6-dichloropyridine-2-carboxylic acid potassium salt 377.6g, mass content 92.8%, yield 98.3%.
Embodiment 3
In reaction flask, first add 600mL ethanol, under stirring, add 4-amino-3,6-dichloropyridine-2-carboxylic acid wet product (folding hundred) 300g and 70g sodium hydroxide, temperature rising reflux, is incubated 2 hours, underpressure distillation under reflux, steam second alcohol and water, when steaming thing and reaching 400 ~ 500ml, stop distillation, pour out material, crystallisation by cooling in dish, place after 24 hours, dry, obtain 4-amino-3,6-dichloropyridine-2-carboxylic acid sodium salt 350.2g, mass content 92.5%, yield 97.6%.
Embodiment 4
In reaction flask, first add 600mL ethanol, under stirring, add 4-amino-3,6-dichloropyridine-2-carboxylic acid wet product (folding hundred) 300g and 95g potassium hydroxide, temperature rising reflux, is incubated 2 hours, underpressure distillation under reflux, steam ethanol, when steaming ethanol and reaching 400 ~ 500ml, stop distillation, pour out material, crystallisation by cooling in dish, place after 24 hours, dry, obtain 4-amino-3,6-dichloropyridine-2-carboxylic acid potassium salt 374.1g, mass content 93.1%, yield 97.7%.
Comparative example 1
In reaction flask, first add 450mL water, under stirring, add 4-amino-3,6-dichloropyridine-2-carboxylic acid wet product (folding hundred) 200g and 45g sodium hydroxide, temperature rising reflux, is incubated 2 hours, underpressure distillation under reflux, steam water, when steaming thing and reaching 350 ~ 400ml, stop distillation, pour out material, crystallisation by cooling in dish, place after 24 hours, dry, obtain 4-amino-3,6-dichloropyridine-2-carboxylic acid sodium salt 231.7g, mass content 88.5%, yield 92.7%.
Comparative example 2
In reaction flask, first add 600mL water, under stirring, add 4-amino-3,6-dichloropyridine-2-carboxylic acid wet product (folding hundred) 300g and 90g potassium hydroxide, temperature rising reflux, is incubated 2 hours, underpressure distillation under reflux, steam methyl alcohol, when steaming thing and reaching 450 ~ 500ml, stop distillation, pour out material, crystallisation by cooling in dish, place after 24 hours, dry, obtain 4-amino-3,6-dichloropyridine-2-carboxylic acid potassium salt 371.7g, mass content 89.4%, yield 93.2%.
Claims (10)
1. the preparation method of 4-amino-3, a 6-dichloropyridine-2-carboxylate salt, is characterized in that 4-amino-3,6-dichloropyridine-2-carboxylic bronsted lowry acids and bases bronsted lowry carries out salt-forming reaction in alcoholic solvent at 60 ~ 80 DEG C, crystallization after reaction, dry, obtain 4-amino-3,6-dichloropyridine-2-carboxylate salt; Described alcoholic solvent is lower alcohols solvent, and described alkali is alkali metal hydroxide.
2. method according to claim 1, is characterized in that described alcoholic solvent is methyl alcohol or ethanol.
3. method according to claim 1, is characterized in that the consumption of described alcoholic solvent is 0.6 ~ 5 times of amino-3, the 6-dichloropyridine-2-carboxylic acid quality of 4-.
4. method according to claim 3, is characterized in that the consumption of described alcoholic solvent is 1 ~ 3 times of amino-3, the 6-dichloropyridine-2-carboxylic acid quality of 4-.
5. method according to claim 1, is characterized in that salt-forming reaction is under reflux conditions carried out.
6. method according to claim 1, after it is characterized in that salt-forming reaction, underpressure distillation removes the solvent of 60% ~ 100%, then cooling crystallization.
7. method according to claim 6, after it is characterized in that salt-forming reaction, underpressure distillation removes the solvent of 70% ~ 95%.
8. method according to claim 1, is characterized in that described alkali is sodium hydroxide or potassium hydroxide.
9. method according to claim 1, is characterized in that mol ratio 1:0.5 ~ 1.5 of amino-3, the 6-dichloropyridine-2-carboxylic acids of described 4-and alkali.
10. method according to claim 9, is characterized in that mol ratio 1:1 ~ 1.2 of amino-3, the 6-dichloropyridine-2-carboxylic acids of described 4-and alkali.
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107778226A (en) * | 2016-08-26 | 2018-03-09 | 利尔化学股份有限公司 | A kind of purification process of the formic acid of 4 amino, 3,6 dichloropyridine 2 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
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CN103619171A (en) * | 2010-11-03 | 2014-03-05 | 陶氏益农公司 | Pesticidal compositions and processes related thereto |
US20140213448A1 (en) * | 2012-04-27 | 2014-07-31 | Dow Agrosciences Llc | Pesticidal compositions and processes related thereto |
CN104115839A (en) * | 2012-06-28 | 2014-10-29 | 永农生物科学有限公司 | Compound pesticide composition containing carfentrazone-ethyl and picloram or salts thereof, preparation thereof and applications of the preparation |
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- 2014-12-28 CN CN201410828311.7A patent/CN104513199A/en active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103619171A (en) * | 2010-11-03 | 2014-03-05 | 陶氏益农公司 | Pesticidal compositions and processes related thereto |
US20140213448A1 (en) * | 2012-04-27 | 2014-07-31 | Dow Agrosciences Llc | Pesticidal compositions and processes related thereto |
CN104115839A (en) * | 2012-06-28 | 2014-10-29 | 永农生物科学有限公司 | Compound pesticide composition containing carfentrazone-ethyl and picloram or salts thereof, preparation thereof and applications of the preparation |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107778226A (en) * | 2016-08-26 | 2018-03-09 | 利尔化学股份有限公司 | A kind of purification process of the formic acid of 4 amino, 3,6 dichloropyridine 2 |
CN107778226B (en) * | 2016-08-26 | 2019-07-02 | 利尔化学股份有限公司 | A kind of purification process of 4- amino -3,6- dichloropyridine -2- formic acid |
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