CN101481311A - Preparation of 4-chloro-2-nitrophenol - Google Patents
Preparation of 4-chloro-2-nitrophenol Download PDFInfo
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- CN101481311A CN101481311A CNA2008101541254A CN200810154125A CN101481311A CN 101481311 A CN101481311 A CN 101481311A CN A2008101541254 A CNA2008101541254 A CN A2008101541254A CN 200810154125 A CN200810154125 A CN 200810154125A CN 101481311 A CN101481311 A CN 101481311A
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- chloro
- nitrophenols
- nitrophenol
- sodium
- activated carbon
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Abstract
The invention relates to an improved synthetic method for 4-chlorine-2-nitrophenol. In the method, active carbon is adopted to absorb the organic impurities in the reaction process and then the active carbon is removed by filtering. By adopting the method, the quality of the 4-chlorine-2-nitrophenol is improved, the industrial cost is lowered and meanwhile, the destruction to the ecological environment is lessened.
Description
Technical field
The invention belongs to the preparation method of medicine intermediate, dyestuff intermediate, particularly relate to the preparation method of 4-chloro-2-nitrophenols.
Background technology
4-chloro-2-nitrophenols is an important intermediate of producing medicine and dyestuff, Laser Printing material, be mainly used in the neuralgic medicine-chlorazol of synthetic treatment stop hydrazone, produce mordant dyes and be used for the charge adjusting agent of Laser Printing material, use this product just can further synthesize the said products through hydrogenating reduction, because the special purpose of this product, therefore high to the quality requirements of this product, the product purity of the preparation method's preparation in producing at present is low, impurity is many, can not satisfy the needs of producing high-quality product.Being prepared as follows of a for example present 4-chloro-2-nitrophenols:
1, hydrolysis
In the hydrolytic decomposition pot of 3000L, add water 2100L, adding concentration is the NaOH solution (wherein NaOH solid 202Kg) of 75-80g/L, add 2 of 400Kg then, the 5-dichloronitrobenzene, sealed reactor, stir and intensification, in 1-1.5 hour, be warming up to 130-136 ℃ of reaction and finish, be pressed into the crystallization retort.
2, distillation
The crystallization retort is warming up to 100-105 ℃, in reflux, does not have 2, stop to distill this distillation time during the 5-dichloronitrobenzene and be generally 2-2.5 hour.
3, crystallization
After distillation finished, with moisturizing 500L in the retort, making its relative density at 80-90 ℃ of adding Industrial Salt 300Kg was 1.18-1.20 (this density is 25 ℃ of measurements), is cooled to 25 ℃ of filtrations then, gets 4-chloro-2-p-nitrophenol sodium filter cake.
4, neutralization
With above-mentioned filter cake making beating, add hydrochloric acid to pH=5-5.5, get 4-chloro-2-nitrophenols.
5, suction filtration
Material is cooled to 25 ℃, and suction filtration gets the filter cake packing.
This technology is owing to impurity in the product that produces is more, and the purity of product is lower.
The present invention finds the preparation method that a kind of quality that can make product 4-chloro-2-nitrophenols gets a promotion.
Summary of the invention
The technical problem to be solved in the present invention is to overcome to contain impurity in the building-up process, cause product purity not high enough, the present invention is to remove impurity in the product by activated carbon to existing preparation method's improvement, has reduced the impurity in the product, has improved the purity of product.
The present invention also provides improving one's methods of a kind of 4-of preparation chloro-2-nitrophenols, the method comprising the steps of (a) 2, the hydrolysis reaction of 5-dichloronitrobenzene and sodium hydroxide, (b) condensing crystal of hydrolysate 4-chloro-2-p-nitrophenol sodium, (c) 4-chloro-2-p-nitrophenol sodium is refining, (d) get 4-chloro-2-nitrophenols and (e) dry and packing 4-chloro-2-nitrophenols with 4-chloro-2-p-nitrophenol sodium in, wherein the organic impurity that adds in the activated carbon adsorption reaction process in (c) step removes by filter activated carbon then.
In the above-mentioned method for preparing 4-chloro-2-nitrophenols, (c) amount of the activated carbon that adds of step is the 0.1-2.0 ‰ of 4-chloro-2-p-nitrophenol sodium overall solution volume, is preferably 0.5-1.5 ‰, especially preferably 1 ‰.
More concrete is, the invention provides improving one's methods of a kind of 4-of preparation chloro-2-nitrophenols, and this method comprises the steps:
(a) hydrolysis: dissolved solids sodium hydroxide in hydrolytic decomposition pot, add 2 then, the 5-dichloronitrobenzene, the sealed reaction jar is warming up to 142-148 ℃ with jacket steam, reaction pressure 0.25-0.30mpa, insulation reaction 8-12 hour.
(b) condensing crystal: hydrolysis reaction is pressed into the condensing crystal jar with reactant and stirs successively, distills, lowers the temperature after finishing, and obtains the red crystallization of 4-chloro-2-p-nitrophenol sodium.
(c) refining: as in the treatment tank that adds end water, to add 4-chloro-2-p-nitrophenol sodium crystallization dissolving, add gac, be heated to 60-90 ℃ and make the crystallization dissolving, stirred then 20-50 minute, seal treatment tank then, pressurized air is pressed into pressure filter with 4-chloro-2-nitrophenols sodium solution and takes off gac, with filtrate collection in neutralization tank.
(d) the 4-chloro-2-nitrophenols sodium solution in the neutralization tank is cooled to 25-30 ℃ and adds technical hydrochloric acid, transfer the faint yellow crystallization of pH=5-5.5 faint yellow 4-chloro-2-nitrophenols to separate out.
(e) dry, pack: the crystallization of 4-chloro-2-nitrophenols is dried the back with centrigugal swing dryer pack.
In the aforesaid method provided by the invention, (c) amount that adds activated carbon in the step can be decided according to the decolouring situation of reaction process solution, the amount that adds activated carbon generally speaking is the 0.1-2.0 ‰ of 4-chloro-2-p-nitrophenol sodium liquor capacity, is preferably 0.5-1.5 ‰, especially preferably 1 ‰.
More specifically, the invention provides a kind of method that is prepared as follows
(a) hydrolysis: in 30001 hydrolytic decomposition pot, add water 25001 and start stirring, throw solid sodium hydroxide 1922Kg and drop into 2 again, 5-dichloronitrobenzene 392Kg sealed reaction jar is warming up to 142-148 ℃ of reaction pressure 0.25-0.30mpa, insulation reaction 9.5-11 hour with jacket steam;
(b) condensing crystal: after hydrolysis reaction finishes, reactant is pressed into the condensing crystal jar, start stirring, under 104-110 ℃ of condition, distillation concentrates 40-60 minute, steam the about 200-2501 of moisture, stop to concentrate, open the chuck water coolant, hydrolyzate is cooled to 25-40 ℃, the red crystallization of 4-chloro-2-p-nitrophenol sodium is separated out, and puts into the suction filtration groove under the agitation condition;
(c) refining: as in 50001 treatment tank, to put under end water 25001 agitation conditions, add 4-chloro-2-p-nitrophenol sodium filter cake 270Kg and be warming up to 50 ℃ by 1-5 ‰ adding gac, it is molten entirely to continue to be warming up to 85-90 ℃ of material, with this understanding, continue to stir 15-40 minute, terminal point arrives, the sealed reaction jar, pressurized air is pressed into pressure filter with material and takes off gac, and material collection is standby in neutralization tank;
(d) the 4-chloro-2-nitrophenols sodium solution in the neutralization tank is cooled to 25-40 ℃ and adds technical hydrochloric acid, transfer the faint yellow crystallization of pH=2-5.5 faint yellow 4-chloro-2-nitrophenols to separate out;
(e) dry, pack: after 4-chloro-2-nitrophenols filter cake is dried with centrigugal swing dryer, packing.
Preparation method's of the present invention beneficial effect is that gac is removed gac with the organic impurity of absorption reaction process with filter method after the crystallization, and other organic magazine amounts reduce relatively.
Embodiment
Describe the present invention in detail below in conjunction with specific embodiment, effect of the present invention is made further proof, but this embodiment does not form any qualification to the scope of the invention.
Specifically described the preparation method of 4-chloro-2-nitrophenols below:
Embodiment 1
(a) hydrolysis: in the hydrolytic decomposition pot of 3000L, add water 2500L and start stirring, throw solid sodium hydroxide 1922Kg (100%), drop into 2 again, 5-dichloronitrobenzene 392Kg (100%) sealed reaction jar, be warming up to 146 ℃ with jacket steam, reaction pressure 0.30mpa, insulation reaction 11 hours.
(b) condensing crystal: after hydrolysis reaction finishes, reactant is pressed into the condensing crystal jar, starts stirring, under 106 ℃ of conditions, distillation concentrates 60 minutes, steam the about 250L of moisture, stop to concentrate, open the chuck water coolant, hydrolyzate is cooled to 30 ℃, the red crystallization of 4-chloro-2-p-nitrophenol sodium is separated out, and puts into the suction filtration groove under the agitation condition, and suction filtration gets 4-chloro-2-p-nitrophenol sodium filter cake.
(c) refining: as in the treatment tank of 5000L, to put end water 2500L, agitation condition adds 4-chloro-2-p-nitrophenol sodium filter cake 270Kg down and is warming up to 50 ℃, the amount of pressing cumulative volume 2 ‰ adds gac, continues to be warming up to 87 ℃, all dissolves until filter cake, with this understanding, continue to stir 30 minutes, terminal point arrives, the sealed reaction jar, pressurized air is pressed into pressure filter with 4-chloro-2-nitrophenols sodium solution and takes off gac, and solution is collected in the neutralization tank.
(d) the 4-chloro-2-nitrophenols sodium solution in the neutralization tank is cooled to 25-30 ℃ and adds technical hydrochloric acid, transfer pH=5.5, the faint yellow crystallization of faint yellow 4-chloro-2-nitrophenols is separated out.
(e) dry, pack: after the crystallization of 4-chloro-2-nitrophenols is dried with centrigugal swing dryer, packing, productive rate is 90.14%.
Repeat old technology (production process of old technology is the method that background technology of the present invention is partly introduced) and embodiment 1 respectively 4 times respectively, the foreign matter content contrast of the product of embodiment 1 preparation and the product of old explained hereafter is shown in (liquid-phase chromatographic analysis) in the table 1
Table 1
From this table as can be seen, method of the present invention has reduced the content of impurity in the product.So method of the present invention has shown outstanding substance progress than existing method.
The preparation method of 4-chloro-2-nitrophenols of the present invention is described by specific embodiment.Those skilled in the art can use for reference links such as content appropriate change raw material of the present invention, processing condition and realize corresponding other purpose, its relevant change does not all break away from content of the present invention, all similar replacements and change will become apparent to those skilled in the art that and all be regarded as comprising within the scope of the present invention.
Claims (4)
1, a kind of method for preparing 4-chloro-2-nitrophenols, the method comprising the steps of (a) 2, the hydrolysis reaction of 5-dichloronitrobenzene and sodium hydroxide, (b) condensing crystal of hydrolysate 4-chloro-2-p-nitrophenol sodium, (c) 4-chloro-2-p-nitrophenol sodium is refining, (d) get 4-chloro-2-nitrophenols and (e) dry and packing 4-chloro-2-nitrophenols with 4-chloro-2-p-nitrophenol sodium in, it is characterized in that adding in (c) step the organic impurity in the activated carbon adsorption reaction process, remove by filter activated carbon then.
2, method according to claim 1 is characterized in that the amount of the activated carbon that (c) step adds is the 0.1-2.0 ‰ of 4-chloro-2-p-nitrophenol sodium overall solution volume.
3, method according to claim 2 is characterized in that the amount of the activated carbon that (c) step adds is the 0.5-1.5 ‰ of 4-chloro-2-p-nitrophenol sodium overall solution volume.
4, method according to claim 3 is characterized in that the amount of the activated carbon that (c) step adds is 1 ‰ of a 4-chloro-2-p-nitrophenol sodium overall solution volume.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2008101541254A CN101481311A (en) | 2008-12-12 | 2008-12-12 | Preparation of 4-chloro-2-nitrophenol |
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| Application Number | Priority Date | Filing Date | Title |
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| CNA2008101541254A CN101481311A (en) | 2008-12-12 | 2008-12-12 | Preparation of 4-chloro-2-nitrophenol |
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| CN101481311A true CN101481311A (en) | 2009-07-15 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102617354A (en) * | 2012-03-07 | 2012-08-01 | 安徽海华化工有限公司 | Refining process of o-nitrophenol |
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2008
- 2008-12-12 CN CNA2008101541254A patent/CN101481311A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102617354A (en) * | 2012-03-07 | 2012-08-01 | 安徽海华化工有限公司 | Refining process of o-nitrophenol |
| CN102617354B (en) * | 2012-03-07 | 2014-01-01 | 安徽海华科技股份有限公司 | Refining process of o-nitrophenol |
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Application publication date: 20090715 |