CN103193703B - Purifying method of 2, 3-dichloropyridine - Google Patents
Purifying method of 2, 3-dichloropyridine Download PDFInfo
- Publication number
- CN103193703B CN103193703B CN201310149040.8A CN201310149040A CN103193703B CN 103193703 B CN103193703 B CN 103193703B CN 201310149040 A CN201310149040 A CN 201310149040A CN 103193703 B CN103193703 B CN 103193703B
- Authority
- CN
- China
- Prior art keywords
- dichloropyridine
- product
- liquid
- sample
- purification
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Abstract
The invention discloses a purifying method of 2,3-dichloropyridine. The purifying method comprises the following steps of: mixing a crude 2, 3-dichloropyridine product, a treating agent and an organic solvent to form a liquid phase reaction system, and enabling the liquid phase reaction system to react at the temperature of 20-90DEG C; extracting a sample from the liquid phase reaction system, detecting the sample by using liquid chromatography under the detection conditions that the wavelength is 235nm and the volume ratio of methanol to water in a moving phase is 70:30, and when the content of 2,3,6-trichloropyridine in the sample is less than 0.5 percent, ending the reaction, or continuously reacting; and preparing a product solution after the reaction is ended, then cooling the product solution so that a crystallized product is sufficiently separated out, carrying out solid-liquid separation to obtain the crystallized product, adding the crystallized product to water so as to form a dispersed system, adjusting the pH of the dispersed system to be 1-4 by using inorganic acid, and filtering the dispersed system to obtain solid matters, namely the purified 2, 3-dichloropyridine.
Description
Technical field
The present invention relates to a kind of 2, the method for purification of 3-dichloropyridine.
Background technology
2,3-dichloropyridine is the key intermediate of synthetic pesticide Rynaxypyr, and its content has directly determined the selectivity of subsequent reactions and the quality of the finished product Rynaxypyr.2 of domestic production manufacturer production, 3-dichloropyridine, if under the testing conditions of wavelength 235nm, mobile phase methanol: water=70:30, adopts liquid chromatographic detection, and its main content is greater than 95%, major impurity content 2-4%.
Impurity is mainly 2,3,6-trichloropyridine, 2,3,6-trichloropyridine is 2, in 3-dichloropyridine building-up process, excessively the result of chlorination is difficult to avoid completely its generation in building-up process, and the existence of 2,3,6-trichloropyridine causes subsequent handling product selectivity to decline, intermediate material viscosity is high, not easy to operate, operation is unstable, and the finished product Rynaxypyr product quality is affected.
Therefore reduce by 2, in 3-dichloropyridine product 2,3, the content of 6-trichloropyridine is the key of producing high-quality Rynaxypyr, purify 2 at present, the method of 3-dichloropyridine is mainly recrystallizing methanol method, utilizes the difference of the two solubleness in methyl alcohol, and separation is met the product that the content of domestic correspondent requirement is greater than 95%.Due to 2,3-dichloropyridine and 2,3,6-trichloropyridine structure is close, the character such as solubleness are close, therefore utilize the method for purification of recrystallizing methanol can only accomplish that content is greater than 95%(235nm), and content still can exert an influence to follow-up products production at the foreign matter content of 2-4%.
Utilize the method for recrystallizing methanol under 235nm wavelength, the content of 2,3-dichloropyridine is brought up to more than 99%, can consume a large amount of methyl alcohol, product yield only has the 15-20% before processing.Therefore seek a kind of removal method, fundamentally remove byproduct, can improve product yield, be the industrial problem of being badly in need of solution simultaneously.
The detection method of 2,3-dichloropyridine, two kinds of liquid-phase chromatography methods of current domestic existence, mainly to detect wavelength difference: a kind of is to detect under 265nm wavelength, to impurity 2,3, the response value of 6-trichloropyridine is on the low side, the product therefore detecting in this way, and content is more than 99%; The second is to detect under 235nm wavelength, and to impurity 2,3, the response value of 6-trichloropyridine is high, and main content is more than 95%; Therefore same 2,3, different wavelength detection for-dichloropyridine sample, there is large difference in content; At present, domestic 2,3-dichloropyridine manufacturer adopts 265nm wavelength to detect, and its product content is greater than 99%, and Rynaxypyr manufacturer adopts 235nm wavelength to detect, its raw material 2, and it is that content is greater than 95% that 3-dichloropyridine enters emblem mark standard.
Due to the difference of detection method, and there is no industry standard or national standard, 2,3-dichloropyridine manufacturing enterprise and use enterprise are often because test result is led to divergence.And fundamentally find a kind of 2, the method for purification of 3-dichloropyridine, thoroughly separated 2,3, the 6-trichloropyridine of removing, makes it no matter use which kind of detection method, content, all more than 99%, is only the key of dealing with problems.
Summary of the invention
The object of this invention is to provide a kind of 2, the method for purification of 3-dichloropyridine.
In order to realize foregoing invention object, provided by the present invention 2, the method of purification of 3-dichloropyridine comprises the following steps: 2,3-dichloropyridine crude product, treatment agent and organic solvent are mixed to form to liquid-phase reaction system, under temperature 20-90 ℃ condition, liquid-phase reaction system are reacted; From liquid-phase reaction system, extracting sample, is that 235nm, moving phase are under the volume ratio of the first alcohol and water testing conditions that is 70: 30 at wavelength, with in liquid chromatographic detection sample 2,3, when the content of 6-trichloropyridine is less than 0.5%, finishes reaction, otherwise continues reaction; After finishing, reaction makes product solution, then cooled product solution is fully separated out crystallized product, solid-liquid separation obtains crystallized product and crystallized product is added to the water and makes it to form dispersion system, with mineral acid, regulating the pH value of dispersion system is 1-4, the solids that filtration dispersion system obtains is 2 after purifying, 3-dichloropyridine.
Described treatment agent is the aqueous solution of Monomethylamine, dimethylamine or hydrazine hydrate.
In described Monomethylamine, dimethylamine and hydrazine hydrate and 2,3-dichloropyridine crude product 2,3, the mol ratio of 6-trichloropyridine is 1.1: 1.
Described mineral acid is selected hydrochloric acid or sulfuric acid.
Described organic solvent is selected methyl alcohol or ethanol.
Temperature condition-10 that described crystallized product is separated out are ℃ to 25 ℃.
The water consumption of described formation dispersion system is 3-10 times of crystallized product quality.
Compared with prior art, the invention has the advantages that: utilize 2,3, the difference of 6-trichloropyridine and 2,3-dichloropyridine and treatment agent speed of response, the product of generation is soluble in water, and 2,3-dichloropyridine is slightly soluble in water, reach and 2, the thorough separation of 3-dichloropyridine, fundamentally reaches separating effect, through this treatment process, impurity 2, the content of 3,6-trichloropyridine is less than 0.5%, meets existing all testing conditions and all customer requirements.
Embodiment
Further illustrate by the following examples the method for purification of 2,3-dichloropyridine, these embodiment only do not limit the present invention for the present invention is described.In embodiment, its related substances, all under the testing conditions of wavelength 235nm, mobile phase methanol: water=70:30, adopts liquid chromatographic detection to obtain.In embodiment in related raw material: monomethylamine aqueous solution adopts the industrial goods of commercially available concentration 40%, dimethylamine agueous solution adopts the industrial goods of commercially available concentration 40%, hydrazine hydrate aqueous solution adopts the industrial goods of commercially available concentration 80%, and hydrochloric acid is for adopting the industrial goods of commercially available concentration 31%.Sulfuric acid adopts the industrial goods of commercially available concentration 98%, the industrial goods that methyl alcohol, ethanol adopt content to be greater than 99%.Above-mentioned each raw material adopts industrial goods, its objective is in order to obtain easily, and be not limiting the scope of the invention.
Embodiment 1
By 100 gram 2,3-dichloropyridine crude product (main content 72%, 2,3, the content 25% of 6-trichloropyridine) is dissolved in 100 grams of methyl alcohol, then adds 11.7 grams of the monomethylamine aqueous solutions of concentration 40%, forms liquid-phase reaction system; Under 20 ℃ of temperature and agitation condition, liquid-phase reaction system is reacted; From liquid-phase reaction system, extract sample, and use liquid chromatographic detection sample, if foreign matter content is greater than 0.5% in sample, continue to make liquid-phase reaction system to react, and then extract sample and carry out liquid chromatographic detection, once foreign matter content in sample be detected, be less than 0.5%, finish reaction.After finishing, reaction makes product solution, then cooled product solution is to-10 ℃, crystallized product is fully separated out, suction filtration obtains 85 grams of crystallized products, crystallized product is added in 255 grams of water, be uniformly mixed rear formation dispersion system, with hydrochloric acid, regulating the pH value of dispersion system is 1, filtration dispersion system obtains 64 grams of solidss and is 2 after purification, 3-dichloropyridine.Through liquid chromatographic detection, its content is 99.08%, 2,3-dichloropyridine yield 88.8%.
Embodiment 2
By 100 gram 2,3-dichloropyridine crude product (main content 72%, 2,3, the content 25% of 6-trichloropyridine) is dissolved in 100 grams of methyl alcohol, then adds 16.99 grams of the dimethylamine agueous solutions of concentration 40%, forms liquid-phase reaction system; Under 90 ℃ of temperature and agitation condition, liquid-phase reaction system is reacted; From liquid-phase reaction system, extract sample, and use liquid chromatographic detection sample, if foreign matter content is greater than 0.5% in sample, continue to make liquid-phase reaction system to react, and then extract sample and carry out liquid chromatographic detection, once foreign matter content in sample be detected, be less than 0.5%, finish reaction.After finishing, reaction makes product solution, then cooled product solution to 25 ℃, crystallized product is fully separated out, suction filtration obtains 65 grams of crystallized products, crystallized product is added in 650 grams of water, be uniformly mixed rear formation dispersion system, with hydrochloric acid, regulating the pH value of dispersion system is 4, filtration dispersion system obtains 34 grams of solidss and is 2 after purification, 3-dichloropyridine.Through liquid chromatographic detection, its content is 99.58%, 2,3-dichloropyridine yield 47.2%.
Embodiment 3
By 100 gram 2,3-dichloropyridine crude product (main content 72%, 2,3, the content 25% of 6-trichloropyridine) is dissolved in 100 grams of ethanol, then adds 9.44 grams of the hydrazine hydrate aqueous solutions of concentration 80%, forms liquid-phase reaction system; Under 40 ℃ of temperature and agitation condition, liquid-phase reaction system is reacted; From liquid-phase reaction system, extract sample, and use liquid chromatographic detection sample, if foreign matter content is greater than 0.5% in sample, continue to make liquid-phase reaction system to react, and then extract sample and carry out liquid chromatographic detection, once foreign matter content in sample be detected, be less than 0.5%, finish reaction.After finishing, reaction makes product solution, then cooled product solution to 5 ℃, crystallized product is fully separated out, suction filtration obtains 88 grams of crystallized products, crystallized product is added in 560 grams of water, be uniformly mixed rear formation dispersion system, with hydrochloric acid, regulating the pH value of dispersion system is 2, filtration dispersion system obtains 67 grams of solidss and is 2 after purification, 3-dichloropyridine.Through liquid chromatographic detection, its content is 99.28%, 2,3-dichloropyridine yield 93%.
Embodiment 4
By 100 gram 2,3-dichloropyridine crude product (main content 50%, 2,3, the content 45% of 6-trichloropyridine) is dissolved in 100 grams of ethanol, then adds 16.99 grams of the hydrazine hydrate aqueous solutions of concentration 80%, forms liquid-phase reaction system; Under 80 ℃ of temperature and agitation condition, liquid-phase reaction system is reacted; From liquid-phase reaction system, extract sample, and use liquid chromatographic detection sample, if foreign matter content is greater than 0.5% in sample, continue to make liquid-phase reaction system to react, and then extract sample and carry out liquid chromatographic detection, once foreign matter content in sample be detected, be less than 0.5%, finish reaction.After finishing, reaction makes product solution, then cooled product solution to 0 ℃, crystallized product is fully separated out, suction filtration obtains 92 grams of crystallized products, crystallized product is added in 736 grams of water, be uniformly mixed rear formation dispersion system, with sulfuric acid, regulating the pH value of dispersion system is 3, filtration dispersion system obtains 48 grams of solidss and is 2 after purification, 3-dichloropyridine.Through liquid chromatographic detection, its content is 99.38%, 2,3-dichloropyridine yield 96%.
Embodiment 5
By 100 gram 2,3-dichloropyridine crude product (main content 50%, 2,3, the content 45% of 6-trichloropyridine) is dissolved in 100 grams of methyl alcohol, then adds 21.07 grams of the monomethylamine aqueous solutions of concentration 40%, forms liquid-phase reaction system; Under 35 ℃ of temperature and agitation condition, liquid-phase reaction system is reacted; From liquid-phase reaction system, extract sample, and use liquid chromatographic detection sample, if foreign matter content is greater than 0.5% in sample, continue to make liquid-phase reaction system to react, and then extract sample and carry out liquid chromatographic detection, once foreign matter content in sample be detected, be less than 0.5%, finish reaction.After finishing, reaction makes product solution, then cooled product solution to 10 ℃, crystallized product is fully separated out, suction filtration obtains 87 grams of crystallized products, crystallized product is added in 435 grams of water, be uniformly mixed rear formation dispersion system, with sulfuric acid, regulating the pH value of dispersion system is 2, filtration dispersion system obtains 46 grams of solidss and is 2 after purification, 3-dichloropyridine.Through liquid chromatographic detection, its content is 99.11%, 2,3-dichloropyridine yield 92%.
Claims (5)
1. one kind 2, the method for purification of 3-dichloropyridine, is characterized in that comprising the following steps:
By major impurity composition, be 2 of 2,3,6-trichloropyridine, 3-dichloropyridine crude product, treatment agent and organic solvent are mixed to form liquid-phase reaction system, under temperature 20-90 ℃ condition, liquid-phase reaction system are reacted; From liquid-phase reaction system, extracting sample, is that 235nm, moving phase are under the volume ratio of the first alcohol and water testing conditions that is 70: 30 at wavelength, uses liquid chromatographic detection sample, in sample 2,3, when the content of 6-trichloropyridine is less than 0.5%, finish reaction, otherwise continue reaction; After finishing, reaction makes product solution, then cooled product solution is fully separated out crystallized product, solid-liquid separation obtains crystallized product and crystallized product is added to the water and makes it to form dispersion system, with mineral acid, regulating the pH value of dispersion system is 1-4, the solids that filtration dispersion system obtains is 2 after purifying, 3-dichloropyridine; Described treatment agent is the aqueous solution of Monomethylamine, dimethylamine or hydrazine hydrate, and organic solvent is selected methyl alcohol or ethanol.
2. as claimed in claim 12, the method for purification of 3-dichloropyridine, is characterized in that 2,3 in described Monomethylamine, dimethylamine or hydrazine hydrate and 2,3-dichloropyridine crude product, and the mol ratio of 6-trichloropyridine is 1.1: 1.
3. as claimed in claim 12, the method for purification of 3-dichloropyridine, is characterized in that described mineral acid selects hydrochloric acid or sulfuric acid.
4. as claimed in claim 12, the method for purification of 3-dichloropyridine, is characterized in that the temperature condition that described crystallized product is separated out is-10 ℃ to 25 ℃.
5. as claimed in claim 12, the method for purification of 3-dichloropyridine, the water consumption that it is characterized in that described formation dispersion system be crystallized product quality 3-10 doubly.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310149040.8A CN103193703B (en) | 2013-04-26 | 2013-04-26 | Purifying method of 2, 3-dichloropyridine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310149040.8A CN103193703B (en) | 2013-04-26 | 2013-04-26 | Purifying method of 2, 3-dichloropyridine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103193703A CN103193703A (en) | 2013-07-10 |
| CN103193703B true CN103193703B (en) | 2014-10-15 |
Family
ID=48716539
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310149040.8A Active CN103193703B (en) | 2013-04-26 | 2013-04-26 | Purifying method of 2, 3-dichloropyridine |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103193703B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104698100B (en) * | 2015-03-25 | 2017-05-10 | 江苏宝众宝达药业有限公司 | Method for measuring residual solvent methanol in chloropyridine by head-space gas chromatography |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005070888A2 (en) * | 2004-01-23 | 2005-08-04 | E.I. Dupont De Nemours And Company | Process for the manufacture of 2,3-dichloropyridine |
| CN101302190A (en) * | 2008-06-30 | 2008-11-12 | 河北亚诺化工有限公司 | Method for preparing 2,3-dichloropyridine |
| US20100160641A1 (en) * | 2008-12-19 | 2010-06-24 | Jubilant Organosys Ltd. | Process for producing dihalopyridines |
-
2013
- 2013-04-26 CN CN201310149040.8A patent/CN103193703B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005070888A2 (en) * | 2004-01-23 | 2005-08-04 | E.I. Dupont De Nemours And Company | Process for the manufacture of 2,3-dichloropyridine |
| CN101302190A (en) * | 2008-06-30 | 2008-11-12 | 河北亚诺化工有限公司 | Method for preparing 2,3-dichloropyridine |
| US20100160641A1 (en) * | 2008-12-19 | 2010-06-24 | Jubilant Organosys Ltd. | Process for producing dihalopyridines |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103193703A (en) | 2013-07-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108658858B (en) | Preparation and refining method of hydroxychloroquine and preparation method of sulfate thereof | |
| CN101486669B (en) | Method for synthesizing taurine | |
| CN102476990A (en) | Method for extracting and refining long-chain dicarboxylic acid crude product | |
| CN103497100A (en) | Double-stage purification method of long chain dicarboxylic acid aqueous phase | |
| CN102476987B (en) | Method for refining long chain binary acid by combining ultrafiltration and liquid-liquid extraction | |
| CN104591994B (en) | A kind of method of refining long-chain biatomic acid | |
| CN108017535B (en) | Method for extracting long-chain dicarboxylic acid from fermentation liquor | |
| RU2016128516A (en) | PRESSURE RAW MATERIALS CONTAINING UNCLEANED AROMATIC CARBONIC ACIDS | |
| CN103555807A (en) | Method for preparing 7-ACA (aminocephalosporanic acid) and obtaining alpha-aminoadipic acid by one-step enzymatic reaction | |
| CN108975433A (en) | A kind of recovery and treatment method of Iso-Propylalcohol wastewater | |
| CN103193703B (en) | Purifying method of 2, 3-dichloropyridine | |
| KR101529759B1 (en) | Method for producing crystals of adipic acid | |
| CN110914230B (en) | Process for recovering acetic acid from an aqueous stream comprising acetic acid | |
| CN103319415A (en) | A production process for 2-n-propyl-4-methyl-6-(1-methylbenzimidazole-2-yl)benzimidazole | |
| CN103896307A (en) | Method for refining coke oven gas desulfurization waste liquid salt extraction product ammonium sulfate again | |
| US20150018580A1 (en) | Separation method of acetophenone and a-methylbenzly alcohol | |
| CN104591999A (en) | Long chain organic acid purifying method | |
| CA2907759C (en) | Method for extracting ferulic acid and/or its salts | |
| CN106905262A (en) | A kind of method for preparing the HEPES of high-purity 4 | |
| EP3023413B1 (en) | Method for purifying acrylamide alkyl sulfonic acid | |
| CN103570573B (en) | Method for extracting alpha-aminoadipic acid from enzymatic waste liquor | |
| CN103896760B (en) | From containing oxoethanoic acid and oxalic dialdehyde be separated the method for oxoethanoic acid aqueous reaction medium | |
| CN106220646A (en) | A kind of method that recycling of enzymatic clarification cefalexin mother solution | |
| CN103553915A (en) | Method for treating organic salt in thiotriazine ring cyclization mother liquid by use of inorganic acid | |
| CN104003867B (en) | Method for recovering p-hydroxyphenylacetic acid from waste liquid |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |