CN105820039A - Method for separating and purifying 2, 5-dichlorophenol through melt crystallization - Google Patents
Method for separating and purifying 2, 5-dichlorophenol through melt crystallization Download PDFInfo
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- CN105820039A CN105820039A CN201610283094.7A CN201610283094A CN105820039A CN 105820039 A CN105820039 A CN 105820039A CN 201610283094 A CN201610283094 A CN 201610283094A CN 105820039 A CN105820039 A CN 105820039A
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- chlorophenesic acid
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- chlorophenesic
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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
- C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
- C07C37/70—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment
- C07C37/84—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment by crystallisation
Abstract
The invention relates to a method for separating and purifying 2, 5-dichlorophenol through melt crystallization and belongs to the technical field of separation and purification. By means of the method for separating and purifying 2, 5-dichlorophenol through melt crystallization, the problems that when 2, 5-dichlorophenol is separated and purified through existing melt crystallization methods, a great number of losses are caused, and the separation rate is low are solved. Through the separation and purification method, 2, 5-dichlorophenol can be separated out of an isomer mixture of 2, 5- dichlorophenol and 2, 4- dichlorophenol, in addition, few losses are caused, cost is low, operation is simple and convenient, a great amount of energy can be saved, and the requirement of industrialized production can be met. On the premise of guaranteeing a high separation rate, purity of separated 2, 5-dichlorophenol can reach 97% or above.
Description
Technical field
The present invention relates to a kind of separating-purifying 2, the method for 5-chlorophenesic acid, it is more particularly related to a kind of fusion-crystallization separating-purifying 2, the method for 5-chlorophenesic acid, belong to purification technique field.
Background technology
2,5-chlorophenesic acids are a kind of important pesticide, medicine, the intermediate of dyestuff.It is the key intermediate of Benzoinum system herbicide-Mediben.It can be used for synthesizing the products such as nitrogen fertilizer potentiating agent, leather fungicide and DP antifungus agent.
The chlorophenesic acid produced by traditional 1,2,4-trichloro-benzenes Hydrolyze method has 2,5-chlorophenesic acid and 2,4-chlorophenesic acid and 3,4-chlorophenesic acid.A small amount of 3,4-chlorophenesic acid can be removed by simple rectification, and is left more 2, and 5-chlorophenesic acid and 2,4-chlorophenesic acid is difficult to be separated by rectification due to boiling point close (only differing from 1 DEG C).Common from 2,5-chlorophenesic acid and 2, isolating 2 in 4-chlorophenesic acid isomer, the method for 5-chlorophenesic acid has carbamide addition process, direct fused junction crystallization, crystallisation by cooling method and the method utilizing molecular structure difference to be combined with heterocyclic compound, and these methods all exist respective problem.Although carbamide addition process is simple to operate, cost is relatively low, but reaction temperature is high, and abnormal smells from the patient is big.Directly fused junction crystallization can reduce energy consumption significantly, but in operating process, temperature is higher, and product distillation loss is more.Although crystallisation by cooling method is simple to operate, but the separation rate of 2,5-chlorophenesic acids is extremely low, is unfavorable for industrialized production.Utilizing molecular structure difference and heterocyclic compound combined techniques to need to use a large amount of heterocyclic compound, the response time is long, is unfavorable for improving production efficiency.
State Intellectual Property Office discloses Publication No. CN101412664 in 2009.4.22, the invention of entitled " 2,4-chlorophenesic acids and 2, the separation method of 5-dichlorophenol mixture ", the invention provides a kind of 2,4-chlorophenesic acid and 2, the separation method of 5-dichlorophenol mixture, described ultimate principle based on Supramolecular Assembling, utilize and topological between host molecule and guest molecule match, 2 are separated, 4/2,5-mixed dichlorobenzene phenol with the method for molecular recognition.Due to 2,4-chlorophenesic acid and 2,5-chlorophenesic acid is different at spatial configuration of molecules, polarity exists certain difference, thus there is identification abilitys different between distinctive host molecule, and different from the intermolecular interaction difficulty or ease of morpholine or other heterocyclic compounds, by Molecular Recognization, thus reach the purpose separated.The inventive method is from 2, and the product purity obtained in 4/2,5-mixed dichlorobenzene phenol is high, can directly use, improve purity without recrystallization again after separation；And yield is high, method is simple, it is easy to industrialization.
Technique scheme utilizes molecular structure difference and heterocyclic compound combined techniques to need to use a large amount of heterocyclic compound, and the response time is long, is unfavorable for improving production efficiency.
State Intellectual Property Office discloses Publication No. CN101781175A in 2010.7.21, entitled " a kind of separation 2, 4-chlorophenesic acid and 2, the method of 6-chlorophenesic acid " invention, this disclosure of the invention is a kind of separates 2, 4-chlorophenesic acid and 2, the method of 6-chlorophenesic acid, described method is: by 2, 4-chlorophenesic acid and 2, the mixture of 6-chlorophenesic acid is dissolved in organic solvent, add alkaline organic, stirring reaction at a temperature of 40 ~ 80 DEG C, clarify to reactant liquor, reaction terminates, after reactant liquor cooling, stand and separate out crystal, it is filtrated to get filter cake A and filtrate A, 2, 4-chlorophenesic acid is stayed in filtrate A, filter cake A is 2, 6-chlorophenesic acid crude product；Described alkaline organic is triethylene diamine, morpholine, piperazine, ethyl piperazidine or methyl piperazine；Described organic solvent is ethanol, methanol, acetone or ethyl acetate.The efficiency comparison that the present invention separates is high, it is only necessary to primary crystallization, and the total recovery of 2,4-chlorophenesic acids is 90% ~ 95%, purity 96% ~ 99%, the total recovery of 2,6-chlorophenesic acids is 77% ~ 89%, purity 90% ~ 99%, and simple to operate, reproducible, implementation cost is low, is conducive to industry to amplify.
It is long that technique scheme stands precipitation crystal required time so that the production cycle is long, and needed for it, alkaline organic is non-cheap and easy to get simultaneously, can increase production cost, is unfavorable for that realizing industry words produces.
In view of problem above, develop a kind of simplicity, it is possible to from 2,5-chlorophenesic acid and 2, the isomer of 4-chlorophenesic acid efficiently separates out 2, the method for 5-chlorophenesic acid seems particularly necessary.
It is known that fused junction crystallization can reduce energy consumption largely compared to traditional separation methods such as rectification, and reduce the investment of relevant device, apply more the most aborning.And for from 2,5-chlorophenesic acid and 2, the isomer of 4-chlorophenesic acid isolates 2, for 5-chlorophenesic acid, directly fusion-crystallization is used to deposit temperature in operation higher, the problem that product distillation loss is more, though the energy consumption of reducing, separation rate is also had a greatly reduced quality because of product distillation loss.
Summary of the invention
Present invention seek to address that existing fused junction crystallization separating-purifying 2, present in 5-chlorophenesic acid, lose more, that separation rate is low problem, it is provided that a kind of fusion-crystallization separating-purifying 2, the method for 5-chlorophenesic acid.This process for separation and purification can be from 2,5-chlorophenesic acid and 2, isolate 2 in the isomer mixture of 4-chlorophenesic acid, 5-chlorophenesic acid, and lose few, and low cost is easy and simple to handle, can save mass energy, can meet the needs of industrialized production.On the premise of ensureing good separation rate, 2 concurrently separated out, the purity of 5-chlorophenesic acid can reach more than 97%.
In order to realize foregoing invention purpose, play concrete technical scheme as follows:
A kind of fusion-crystallization separating-purifying 2, the method for 5-chlorophenesic acid, it is characterised in that: comprise the following steps that:
A, to the 2 of molten condition, 5-chlorophenesic acid and 2, in the isomer of 4-chlorophenesic acid add organic solvent, obtain mix liquid；
B, mixing liquid step A obtained move in fusion-crystallization device, and system temperature is down to 0-15 DEG C；
System temperature in C, holding step B, crystallisation by cooling, release mother solution；
D, gradually heating up diaphoresis, until diaphoresis final temperature is 20-30 DEG C, collect sweating, remaining crystal is 2,5-chlorophenesic acid crystal.
In step, described 2,5-chlorophenesic acid content 80%, the content of 2,4-chlorophenesic acids is 16% to the present invention.
In step, described organic solvent selects dimethylbenzene, toluene, dioxane, hexamethylene, ethyl acetate or petroleum ether to the present invention.
The preferred dimethylbenzene of above-mentioned organic solvent.
Above-mentioned consumption of organic solvent is 2,5-chlorophenesic acid and 2, the 1-20% of the isomer gross weight of 4-chlorophenesic acid, preferably 10%.
In step, the system temperature of described isomer mixture is 40-50 DEG C to the present invention.
System temperature in stepb, described be down to 0-15 DEG C and referred to, with the rate of temperature fall of 0.04-0.07 DEG C/min, system temperature is down to 0-15 DEG C by the present invention.
The present invention is in step C, and the time of described crystallisation by cooling is 20-50min.
The present invention in step D, the described diaphoresis that gradually heats up, refer to reach diaphoresis final temperature 20-30 DEG C with the heating rate of 0.03-0.06 DEG C/min until diaphoresis final temperature is 20-30 DEG C.
The Advantageous Effects that the present invention brings:
1, the present invention solves existing fused junction crystallization separating-purifying 2, loses more, that separation rate is low problem present in 5-chlorophenesic acid, it is provided that a kind of fusion-crystallization separating-purifying 2, the method for 5-chlorophenesic acid.This process for separation and purification can be from 2,5-chlorophenesic acid and 2, isolate 2 in the isomer mixture of 4-chlorophenesic acid, 5-chlorophenesic acid, and lose few, and low cost is easy and simple to handle, can save mass energy, can meet the needs of industrialized production.On the premise of ensureing good separation rate, 2 concurrently separated out, the purity of 5-chlorophenesic acid can reach more than 97%.
2, the present invention is in step, and the system temperature of described isomer mixture is 40-50 DEG C.Changing temperature range and ensure that 2,5-chlorophenesic acid and 2, the isomer of 4-chlorophenesic acid is in molten condition, beneficially subsequent step and the purity of final product.
3, the present invention is in stepb, described system temperature is down to 0-15 DEG C refers to, with the rate of temperature fall of 0.04-0.07 DEG C/min, system temperature is down to 0-15 DEG C.The restriction of this parameter ensure that major part 2, and 5-chlorophenesic acid and 2, the isomery physical ability of 4-chlorophenesic acid is frozen into crystal, it is simple to lower step carries out intensification diaphoresis purification operations.
4, the present invention is in step D, the described diaphoresis that gradually heats up, and refers to reach diaphoresis final temperature 20-30 DEG C with the heating rate of 0.03-0.06 DEG C/min until diaphoresis final temperature is 20-30 DEG C.The restriction of this parameter is prevented from the too fast or the slowest sweating band impurity efficiency that affects of heating rate, and only in this temperature range, guarantee diaphoresis operation reaches optimal impurity-eliminating effect.
Detailed description of the invention
Embodiment 1
A kind of fusion-crystallization separating-purifying 2, the method for 5-chlorophenesic acid, comprise the following steps that:
A, to the 2 of molten condition, 5-chlorophenesic acid and 2, in the isomer of 4-chlorophenesic acid add organic solvent, obtain mix liquid；
B, mixing liquid step A obtained move in fusion-crystallization device, and system temperature is down to 0 DEG C；
System temperature in C, holding step B, crystallisation by cooling, release mother solution；
D, gradually heating up diaphoresis, until diaphoresis final temperature is 20 DEG C, collect sweating, remaining crystal is 2,5-chlorophenesic acid crystal.
Embodiment 2
A kind of fusion-crystallization separating-purifying 2, the method for 5-chlorophenesic acid, comprise the following steps that:
A, to the 2 of molten condition, 5-chlorophenesic acid and 2, in the isomer of 4-chlorophenesic acid add organic solvent, obtain mix liquid；
B, mixing liquid step A obtained move in fusion-crystallization device, and system temperature is down to 15 DEG C；
System temperature in C, holding step B, crystallisation by cooling, release mother solution；
D, gradually heating up diaphoresis, until diaphoresis final temperature is 30 DEG C, collect sweating, remaining crystal is 2,5-chlorophenesic acid crystal.
Embodiment 3
A kind of fusion-crystallization separating-purifying 2, the method for 5-chlorophenesic acid, comprise the following steps that:
A, to the 2 of molten condition, 5-chlorophenesic acid and 2, in the isomer of 4-chlorophenesic acid add organic solvent, obtain mix liquid；
B, mixing liquid step A obtained move in fusion-crystallization device, and system temperature is down to 7.5 DEG C；
System temperature in C, holding step B, crystallisation by cooling, release mother solution；
D, gradually heating up diaphoresis, until diaphoresis final temperature is 25 DEG C, collect sweating, remaining crystal is 2,5-chlorophenesic acid crystal.
Embodiment 4
A kind of fusion-crystallization separating-purifying 2, the method for 5-chlorophenesic acid, comprise the following steps that:
A, to the 2 of molten condition, 5-chlorophenesic acid and 2, in the isomer of 4-chlorophenesic acid add organic solvent, obtain mix liquid；
B, mixing liquid step A obtained move in fusion-crystallization device, and system temperature is down to 12 DEG C；
System temperature in C, holding step B, crystallisation by cooling, release mother solution；
D, gradually heating up diaphoresis, until diaphoresis final temperature is 26 DEG C, collect sweating, remaining crystal is 2,5-chlorophenesic acid crystal.
Embodiment 5
On the basis of embodiment 1-4:
Preferably, in step, described 2,5-chlorophenesic acid content 80%, the content of 2,4-chlorophenesic acids is 16%.
Preferably, in step, described organic solvent selects dimethylbenzene, toluene, dioxane, hexamethylene, ethyl acetate or petroleum ether.
Further, described organic solvent is dimethylbenzene.
Preferably or further, described consumption of organic solvent is 2,5-chlorophenesic acid and 2, the 1% of the isomer gross weight of 4-chlorophenesic acid.
Preferably, in step, the system temperature of described isomer mixture is 40 DEG C.
Embodiment 6
On the basis of embodiment 1-4:
Preferably, in step, described 2,5-chlorophenesic acid content 80%, the content of 2,4-chlorophenesic acids is 16%.
Preferably, in step, described organic solvent selects dimethylbenzene, toluene, dioxane, hexamethylene, ethyl acetate or petroleum ether.
Further, described organic solvent is dimethylbenzene.
Preferably or further, described consumption of organic solvent is 2,5-chlorophenesic acid and 2, the 20% of the isomer gross weight of 4-chlorophenesic acid.
Preferably, in step, the system temperature of described isomer mixture is 50 DEG C.
Embodiment 7
On the basis of embodiment 1-4:
Preferably, in step, described 2,5-chlorophenesic acid content 80%, the content of 2,4-chlorophenesic acids is 16%.
Preferably, in step, described organic solvent selects dimethylbenzene, toluene, dioxane, hexamethylene, ethyl acetate or petroleum ether.
Further, described organic solvent is dimethylbenzene.
Preferably or further, described consumption of organic solvent is 2,5-chlorophenesic acid and 2, the 10% of the isomer gross weight of 4-chlorophenesic acid.
Preferably, in step, the system temperature of described isomer mixture is 45 DEG C.
Embodiment 8
On the basis of embodiment 1-4:
Preferably, in step, described 2,5-chlorophenesic acid content 80%, the content of 2,4-chlorophenesic acids is 16%.
Preferably, in step, described organic solvent selects dimethylbenzene, toluene, dioxane, hexamethylene, ethyl acetate or petroleum ether.
Further, described organic solvent is dimethylbenzene.
Preferably or further, described consumption of organic solvent is 2,5-chlorophenesic acid and 2, the 18% of the isomer gross weight of 4-chlorophenesic acid.
Preferably, in step, the system temperature of described isomer mixture is 42 DEG C.
Embodiment 9
On the basis of embodiment 1-4:
Preferably, in stepb, described system temperature is down to 0 DEG C refers to that system temperature is down to 0 DEG C by the rate of temperature fall with 0.04 DEG C/min.
Preferably, in step C, the time of described crystallisation by cooling is 20min.
Preferably, in step D, the described diaphoresis that gradually heats up, refer to reach diaphoresis final temperature 20 DEG C with the heating rate of 0.03 DEG C/min until diaphoresis final temperature is 20 DEG C.
Embodiment 10
On the basis of embodiment 1-4:
Preferably, in stepb, described system temperature is down to 15 DEG C refers to that system temperature is down to 15 DEG C by the rate of temperature fall with 0.07 DEG C/min.
Preferably, in step C, the time of described crystallisation by cooling is 50min.
Preferably, in step D, the described diaphoresis that gradually heats up, refer to reach diaphoresis final temperature 30 DEG C with the heating rate of 0.06 DEG C/min until diaphoresis final temperature is 30 DEG C.
Embodiment 11
On the basis of embodiment 1-4:
Preferably, in stepb, described system temperature is down to 7 DEG C refers to that system temperature is down to 7 DEG C by the rate of temperature fall with 0.05 DEG C/min.
Preferably, in step C, the time of described crystallisation by cooling is 35min.
Preferably, in step D, the described diaphoresis that gradually heats up, refer to reach diaphoresis final temperature 25 DEG C with the heating rate of 0.04 DEG C/min until diaphoresis final temperature is 25 DEG C.
Embodiment 12
On the basis of embodiment 1-4:
Preferably, in stepb, described system temperature is down to 5 DEG C refers to that system temperature is down to 5 DEG C by the rate of temperature fall with 0.06 DEG C/min.
Preferably, in step C, the time of described crystallisation by cooling is 30min.
Preferably, in step D, the described diaphoresis that gradually heats up, refer to reach diaphoresis final temperature 26 DEG C with the heating rate of 0.05 DEG C/min until diaphoresis final temperature is 26 DEG C.
Embodiment 13
To the 2 of 100 grams of fusings, 5-chlorophenesic acid and 2, in the isomer of 4-chlorophenesic acid, (system temperature 45 DEG C, wherein 2,5-chlorophenesic acid content 80%, the content of 2,4-chlorophenesic acids is 16%) adds the dimethylbenzene of 10 grams.Then mixed liquor is quickly adding in fusion-crystallization pipe, with the rate of temperature fall of 0.05 DEG C/min, temperature plateau is reduced to 10 DEG C.Crystallisation by cooling half an hour at 10 DEG C, release 10.25 grams of mother solutions.The most gradually heat up diaphoresis, and heating rate is 0.03 DEG C/min-0.06 DEG C/min, and diaphoresis final temperature is 26 DEG C, and the sweating of reception is 20.75 grams, finally obtains the 2 of purity 98%, 5-chlorophenesic acid 66 grams, yield 80.85%.
Claims (10)
1. a fusion-crystallization separating-purifying 2, the method for 5-chlorophenesic acid, it is characterised in that: comprise the following steps that:
A, to the 2 of molten condition, 5-chlorophenesic acid and 2, in the isomer of 4-chlorophenesic acid add organic solvent, obtain mix liquid；
B, mixing liquid step A obtained move in fusion-crystallization device, and system temperature is down to 0-15 DEG C；
System temperature in C, holding step B, crystallisation by cooling, release mother solution；
D, gradually heating up diaphoresis, until diaphoresis final temperature is 20-30 DEG C, collect sweating, remaining crystal is 2,5-chlorophenesic acid crystal.
A kind of fusion-crystallization separating-purifying 2 the most according to claim 1, the method for 5-chlorophenesic acid, it is characterised in that: in step, described 2,5-chlorophenesic acid content 80%, the content of 2,4-chlorophenesic acids is 16%.
A kind of fusion-crystallization separating-purifying 2 the most according to claim 1, the method for 5-chlorophenesic acid, it is characterised in that: in step, described organic solvent selects dimethylbenzene, toluene, dioxane, hexamethylene, ethyl acetate or petroleum ether.
A kind of fusion-crystallization separating-purifying 2 the most according to claim 3, the method for 5-chlorophenesic acid, it is characterised in that: described organic solvent is dimethylbenzene.
5. according to a kind of fusion-crystallization separating-purifying 2 described in claim 1 or 3, the method for 5-chlorophenesic acid, it is characterised in that: described consumption of organic solvent is 2,5-chlorophenesic acid and 2, the 1-20% of the isomer gross weight of 4-chlorophenesic acid.
A kind of fusion-crystallization separating-purifying 2 the most according to claim 5, the method for 5-chlorophenesic acid, it is characterised in that: described consumption of organic solvent is 2,5-chlorophenesic acid and 2, the 10% of the isomer gross weight of 4-chlorophenesic acid.
A kind of fusion-crystallization separating-purifying 2 the most according to claim 1, the method for 5-chlorophenesic acid, it is characterised in that: in step, the system temperature of described isomer mixture is 40-50 DEG C.
A kind of fusion-crystallization separating-purifying 2 the most according to claim 1, the method for 5-chlorophenesic acid, it is characterised in that: in stepb, described system temperature is down to 0-15 DEG C refers to, with the rate of temperature fall of 0.04-0.07 DEG C/min, system temperature is down to 0-15 DEG C.
A kind of fusion-crystallization separating-purifying 2 the most according to claim 1, the method for 5-chlorophenesic acid, it is characterised in that: in step C, the time of described crystallisation by cooling is 20-50min.
A kind of fusion-crystallization separating-purifying 2 the most according to claim 1, the method of 5-chlorophenesic acid, it is characterized in that: in step D, the described diaphoresis that gradually heats up, refer to reach diaphoresis final temperature 20-30 DEG C with the heating rate of 0.03-0.06 DEG C/min until diaphoresis final temperature is 20-30 DEG C.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108047054A (en) * | 2018-01-23 | 2018-05-18 | 贵州大学 | A kind of method of fusion-crystallization separating-purifying neighbour's Iodoaniline |
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| US2708209A (en) * | 1953-10-29 | 1955-05-10 | Olin Mathieson | Process for selective crystallization of 2, 5-dichlorophenol |
| CN102659529A (en) * | 2012-04-27 | 2012-09-12 | 沙隆达集团公司 | Method and device for purifying 2,4-dichlorophenol |
| WO2015082415A1 (en) * | 2013-12-04 | 2015-06-11 | Basf Se | Process for purifying 2,5-dichlorophenol |
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2016
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US2708209A (en) * | 1953-10-29 | 1955-05-10 | Olin Mathieson | Process for selective crystallization of 2, 5-dichlorophenol |
| CN102659529A (en) * | 2012-04-27 | 2012-09-12 | 沙隆达集团公司 | Method and device for purifying 2,4-dichlorophenol |
| WO2015082415A1 (en) * | 2013-12-04 | 2015-06-11 | Basf Se | Process for purifying 2,5-dichlorophenol |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108047054A (en) * | 2018-01-23 | 2018-05-18 | 贵州大学 | A kind of method of fusion-crystallization separating-purifying neighbour's Iodoaniline |
| CN108047054B (en) * | 2018-01-23 | 2020-10-23 | 贵州大学 | Method for separating and purifying o-iodoaniline through melt crystallization |
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Application publication date: 20160803 |