CN109761794A - A kind of salicylic complete alternation method in 3,6- dichlorosalicylic acid preparation process - Google Patents
A kind of salicylic complete alternation method in 3,6- dichlorosalicylic acid preparation process Download PDFInfo
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- CN109761794A CN109761794A CN201711096084.3A CN201711096084A CN109761794A CN 109761794 A CN109761794 A CN 109761794A CN 201711096084 A CN201711096084 A CN 201711096084A CN 109761794 A CN109761794 A CN 109761794A
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Abstract
The present invention provides salicylic complete alternation methods in one kind 3,6- dichlorosalicylic acid preparation process: A) salicylic acid and bromine or hydrogen bromide, are reacted to obtain 5 bromosalicylic acid in concentrated sulfuric acid；B) 5 bromosalicylic acid and chlorine carry out chlorination reaction and obtain the bromo- 3,6- dichlorosalicylic acid of 5-；C) bromo- 3, the 6- dichlorosalicylic acid of 5- under the effect of the catalyst, carries out debromination and obtains 3,6- dichlorosalicylic acid crude product；D) 3,6- dichlorosalicylic acid crude product is recrystallized in dimethylbenzene or toluene, obtains 3,6- dichlorosalicylic acid sterling and impure solvent；The impurity includes 3- chloro-salicylic acid, 3,5- dichlorosalicylic acid and the bromo- 6- chloro-salicylic acid of 3-；E) for impure solvent through alkali cleaning, liquid separation obtains water phase, and catalyst is added in water phase and carries out hydrodehalogenation reaction, Filtration of catalyst, acidification of filtrate obtains salicylic acid reuse to step A).The present invention realizes salicylic acid complete alternation, and environmental benefit is high.
Description
Technical field
The present invention relates to bigcatkin willows in herbicide preparation technical field, more particularly to one kind 3,6- dichlorosalicylic acid preparation process
The complete alternation method of acid.
Background technique
3,6- dichlorosalicylic acids are the key intermediate of herbicide dicamba (dicamba), dicamba (dicamba) chemistry
Scientific name is the chloro- O-Anisic Acid of 3,6- bis-, belongs to the herbicide of benzoic acid system, is a kind of less toxic, efficient, wide spectrum weeding
Agent has significant preventive effect to annual and perennial broadleaf weed, and to gramineous crops such as wheat, corn, millet, rice
Compare safety, is widely applied on foreign agriculture.
Patent WO2015187774 discloses the new technology of one kind 3,6- dichlorosalicylic acid synthesis, using salicylic acid as former material
Material reacts with bromating agent and the bromo- salicylic acid of 5- is made, it is chloro- that 3- then is made with chlorination reaction in sulfuric acid or chlorosulfonic acid system
Then 5 bromosalicylic acid adjusts oleum medium, the reaction was continued is made bromo- 3, the 6- dichlorosalicylic acid of 5-, then in catalyst
Under conditions of palladium or platinum, selective debromination obtains 3,6- dichlorosalicylic acid.Debromination catalyst palladium carbon is expensive, production
It is at high cost.Bromo and chlorination process side reaction are more in this process route, and debromination selection rate is low, and the side reaction of generation produces
Object (3- chloro-salicylic acid, 3,5- dichlorosalicylic acid, the bromo- 6- chloro-salicylic acid of 3-, 5-sulphosalicylic acid and 3- sulfo group -5 bromosalicylic acid)
It is difficult to recycle, the organic matters such as 5-sulphosalicylic acid and 3- sulfo group -5 bromosalicylic acid, COD high, spent acid yield is big, environmental protection
Uncontrolled, whole process is low with salicylic acid collecting rate, and atom utilization is low, and salicylic acid unit consumption is high, and solid waste yield is big, from economy
Upper and technical consideration industrializing implementation difficulty is big.
Summary of the invention
In view of this, the technical problem to be solved in the present invention is that providing water in one kind 3,6- dichlorosalicylic acid preparation process
The complete alternation method of poplar acid, byproduct of reaction are recycled in the form of salicylic.
In order to solve the above technical problems, the present invention provides salicylic complete in one kind 3,6- dichlorosalicylic acid preparation process
Round-robin method, comprising the following steps:
A) salicylic acid and bromine or hydrogen bromide, are reacted in concentrated sulfuric acid, obtain 5 bromosalicylic acid；
B) 5 bromosalicylic acid and chlorine carry out chlorination reaction, obtain bromo- 3, the 6- dichlorosalicylic acid of 5-；
C) bromo- 3, the 6- dichlorosalicylic acid of 5- carries out debromination, obtains 3,6-, bis- chloro-salicyloyl under the effect of the catalyst
Acid crude；
D) 3,6- dichlorosalicylic acid crude product is recrystallized in dimethylbenzene or toluene, obtains 3,6- dichlorosalicylic acid sterling
With impure solvent；The impurity includes 3- chloro-salicylic acid, 3,5- dichlorosalicylic acid and the bromo- 6- chloro-salicylic acid of 3-；
E) for the impure solvent through alkali cleaning, liquid separation obtains water phase, and catalyst is added in water phase, and it is anti-to carry out hydrodehalogenation
It answers, Filtration of catalyst, acidification of filtrate obtains salicylic acid, reuse to step A).
Above-mentioned steps A)~step C) reaction equation it is as follows:
The present invention uses the concentrated sulfuric acid to prepare 5 bromosalicylic acid for solvent, and reaction selectivity is high, high income, odorlessness.
The dosage of the concentrated sulfuric acid is 5-15 times of salicylic acid quality.
The present invention is to the concentrated sulfuric acid and is not particularly limited, can be to be general commercially available, preferably concentration 95%~98%
The concentrated sulfuric acid.
The step A) preferably specifically:
Salicylic acid is dissolved in the concentrated sulfuric acid, temperature is preferably 5 DEG C hereinafter, bromine or hydrogen bromide progress bromine is then added dropwise
Change, obtains 5 bromosalicylic acid.
The bromine and salicylic molar ratio are preferably 0.5:1；The hydrogen bromide is preferably with salicylic molar ratio
1:1。
The step B) preferably specifically:
B1) 5 bromosalicylic acid and chlorine carry out chlorination reaction, obtain the bromo- 3- chloro-salicylic acid of 5-；Then sulfur trioxide is added
And iodine, continue logical chlorine, reaction obtains bromo- 3, the 6- dichlorosalicylic acid of 5-；
B2 it is 20%~40% that system, which) is diluted to sulfuric acid concentration, through cooling, filtering, washing, drying, obtains 5- bromo- 3,6-
Dichlorosalicylic acid sterling and sulfuric acid phase；
B3) through solvent extraction and separation, oil is added to the de- sulfo group of concentrated sulfuric acid esterification and obtains salicylate and 5- bromine water sulfuric acid phase
Poplar acid esters；
B4 after solvent) is distilled off, alkaline hydrolysis, liquid separation, acidification, suction filtration, washing, drying is carried out, salicylic acid and 5- bromine are obtained
Salicylic acid, reuse to step A).
The temperature of the chlorination reaction is preferably 35~45 DEG C, and more preferable 40 DEG C.
The chlorine is passed directly into system in gaseous form.
When the addition sulfur trioxide and iodine, system temperature is preferably 30 DEG C or less.
The sulfur trioxide and the preferred 5:1 of salicylic molar ratio.
The additional amount of the iodine is general catalyst dosage.
After end of reaction, it is preferred that system is diluted to 20%~40% concentrated sulfuric acid concentration, is more preferably diluted to dense sulphur
Acid concentration is 30%, through cooling, filtering, washing, drying, obtains bromo- 3, the 6- dichlorosalicylic acid sterling of 5-.
The diluted solvent is water.
The temperature of above-mentioned cooling is preferably 20-30 DEG C.
Above-mentioned filtered filtrate is sulfuric acid phase, and the present invention carries out solvent extraction and separation to sulfuric acid phase, and oily phase is (i.e. organic
Phase) it the concentrated sulfuric acid is added is esterified de- sulfo group and obtain salicylate and 5 bromosalicylic acid ester.
The solvent preferably includes the alcohol compound of any one and C1~8 in toluene and dimethylbenzene.
The alcohol compound of C1~8 is preferably n-butanol or isoamyl alcohol.
The molar ratio of the toluene or dimethylbenzene and sulfuric acid phase institute sulfur acid is preferably 1:(1~10)；The alcohol of C1~8
The volume ratio of class compound and toluene or dimethylbenzene is preferably 1:(3~10).
The oily phase obtained after extraction and separation, i.e. organic phase, be added the concentrated sulfuric acid carry out being esterified de- sulfo group, obtain salicylate and
5 bromosalicylic acid ester.
The temperature of the esterification is preferably 80~110 DEG C, and the temperature of the de- sulfo group is preferably 110~160 DEG C.
Then the solvent in system is distilled off, surplus materials carries out alkaline hydrolysis, dealcoholysis, acidification, suction filtration, washing, drying, obtains
To salicylic acid and 5 bromosalicylic acid, thus by-product 5-sulphosalicylic acid and 3- sulfo group -5 bromosalicylic acid of reaction are turned respectively
Turn to salicylic acid and 5 bromosalicylic acid, can reuse to above-mentioned steps A).
Above-mentioned alkaline hydrolysis uses this field conventional alkaline aqueous solution, in some embodiments of the invention, uses
The NaOH aqueous solution of concentration 5wt%-15wt%.
The temperature of the alkaline hydrolysis is preferably 98-105 DEG C.
Above-mentioned acidification uses acidic aqueous solution well known to those skilled in the art, in certain specific implementations of the invention
In example, using the HCL aqueous solution of concentration 30%.
The temperature of the acidification is preferably 40-50 DEG C.
Bromo- 3, the 6- dichlorosalicylic acid sterling of obtained 5- carries out debromination, obtains 3,6- under the effect of the catalyst
Dichlorosalicylic acid crude product.
The catalyst can be debromination catalyst well known to those skilled in the art, such as Pt/C, Raney's nickel, metal Pd,
Pt, Fe, Ag, Al, Ni or various metals combination, such as AlCuZn, AlNi, AlCu etc..
It is currently preferred, under alkaline condition, under the action of metal powder, carry out debromination.
Firstly, bromo- 3, the 6- dichlorosalicylic acid of 5- is dissolved under alkaline condition.
The alkaline condition preferably by alkali compounds, as in sodium hydroxide, ammonium hydroxide and potassium hydroxide any one or
A variety of offers.
Any one or more in above-mentioned sodium hydroxide, ammonium hydroxide and potassium hydroxide, the i.e. total amount of alkali compounds, with 5-
The molar ratio of bromo- 3,6- dichlorosalicylic acid is preferably 2~10:1, more preferably 3~5:1.
Above-mentioned dissolution carries out preferably in alkaline compound solution, and the solution is preferably aqueous solution, and concentration is preferably
5%~15%, in some embodiments of the invention, concentration 7%, 8%, 9%, 10%, 11% or 12%.
Then the obtained solution dissolved with bromo- 3, the 6- dichlorosalicylic acid of 5- is mixed with metal powder, is reacted.
The metal powder is preferably any one or more in tin, aluminium, zinc, nickel, iron and magnesium.
In some embodiments of the invention, the metal powder is nickel aluminum metal powder or iron nickel metal
Powder.Alkali compounds is ammonium hydroxide.
In some embodiments of the invention, the metal powder is tin aluminum zinc metal powder.Alkaline chemical combination
Object is potassium hydroxide.
In some embodiments of the invention, the metal powder is tin, aluminium, magnesium, iron or zinc.Alkali compounds is
Sodium hydroxide or potassium hydroxide.
The experimental results showed that metal powder is monometallic powder, such as tin, aluminium, zinc, nickel, iron or magnesium, under alkaline condition,
There is higher selectivity for the removing of phenyl ring hydroxyl contraposition bromine.
The metal powder is generally conventional powder, and the present invention is simultaneously not particularly limited.Its partial size is preferably 1~100 μ
m。
The metal powder preferably with the mass ratio of bromo- 3, the 6- dichlorosalicylic acid of 5- be 0.2~2:1, more preferably 0.5~
0.7:1.
The temperature of the reaction is preferably 25~105 DEG C, and more preferably 50~60 DEG C.
The time of the reaction is preferably 0.5~2h, more preferably 1.0~1.5h.
The solvent of above-mentioned reaction is preferably water.
The form that debrominate product is salt is obtained after reaction.
It is currently preferred, after reaction further include: metal powder reuse, acidification of filtrate, crystallization, filtering is recovered by filtration
Obtain 3,6- dichlorosalicylic acid.
Specifically, being filtered to remove metal powder first, the dilute acid for adjusting pH value of filtrate is crystallized, and filters, and is washed, drying, i.e.,
3,6- dichlorosalicylic acid can be obtained.
The present invention is to above-mentioned diluted acid and is not particularly limited, and can be applicable hydrochloric acid well known to those skilled in the art, sulphur
Acid or nitric acid solution.Its concentration is preferably 20%~35%.
The present invention is to the pH value of system after adjusting and is not particularly limited, and can be adjusted according to those skilled in the art's experience,
Preferably less than 1.
The above-mentioned metal powder being obtained by filtration can be with reuse.
Experiment shows to carry out selective debromination, reaction conversion ratio 100%, receipts under alkaline environment using metal powder
Rate is 98% or more, and product purity is 99% or more, and reacts selectivity with higher.Benefit with higher for salicylic acid
With rate.
It is currently preferred, 3, the 6- dichlorosalicylic acid is carried out to recrystallize further purification, recrystallization solvent two
Toluene or toluene obtain 3,6- dichlorosalicylic acid sterling and impure solvent；The impurity includes 3- chloro-salicylic acid, 3,5- dichloro
Salicylic acid and the bromo- 6- chloro-salicylic acid of 3-.
Currently preferred, for the impure solvent through alkali cleaning, liquid separation obtains water phase, and catalyst is added in water phase, carries out
Hydrodehalogenation reaction, Filtration of catalyst, acidification of filtrate obtain salicylic acid, reuse to step A).
The alkali cleaning uses this field conventional alkaline aqueous solution, in some embodiments of the invention, uses
The NaOH aqueous solution of concentration 5%-15%.Preferably, alkali cleaning to system pH is alkalinity, and preferable ph is 12~13.
Alkali cleaning rear impurity enters water phase, catalyst is added, hydrogen kettle is being added to carry out hydrodehalogenation reaction.The hydrodehalogenation is anti-
It should be carried out in atmosphere of hydrogen.
The catalyst is preferably palladium carbon or Raney's nickel.
The catalyst and the mass ratio of water phase are preferably 0.001~0.02:1.
The temperature of the hydrodehalogenation reaction is preferably 20~100 DEG C, and the time is preferably 0.5~5h, and pressure is preferably 0.1
~1MPa.
Then Filtration of catalyst, catalyst can reuses.
Filtrate is acidified, and impurity 3- chloro-salicylic acid, 3,5- dichlorosalicylic acid and the bromo- 6- chloro-salicylic acid of 3- in system are turned
Turn to salicylic acid, can reuse to step A), and then realize salicylic complete alternation.
Above-mentioned acidification uses acidic aqueous solution well known to those skilled in the art, in certain specific implementations of the invention
In example, using the HCL aqueous solution of concentration 30%.
Compared with prior art, the present invention provides salicylic complete alternations in one kind 3,6- dichlorosalicylic acid preparation process
Method, comprising the following steps: A) salicylic acid and bromine or hydrogen bromide, are reacted in concentrated sulfuric acid, obtain 5 bromosalicylic acid；B)
5 bromosalicylic acid and chlorine carry out chlorination reaction, obtain bromo- 3, the 6- dichlorosalicylic acid of 5-；C) bromo- 3, the 6- dichlorosalicylic acid of 5-,
Under the action of catalyst, debromination is carried out, 3,6- dichlorosalicylic acid crude product is obtained；D) 3,6- dichlorosalicylic acid crude product is in diformazan
It is recrystallized in benzene or toluene, obtains 3,6- dichlorosalicylic acid sterling and impure solvent；The impurity includes 3- chloro-salicyloyl
Acid, 3,5- dichlorosalicylic acid and the bromo- 6- chloro-salicylic acid of 3-；E) the impure solvent is through alkali cleaning, and liquid separation obtains water phase, in water phase
Catalyst is added, carries out hydrodehalogenation reaction, Filtration of catalyst, acidification of filtrate obtains salicylic acid, reuse to step A).This
Invention passes through to by-product 3- chloro-salicylic acid, 3,5- dichlorosalicylic acid, the bromo- 6- chloro-salicylic acid of 3-, 5- sulfo group water in reaction process
Poplar acid and 3- sulfo group -5 bromosalicylic acid are post-processed, and so that it is converted into salicylic acid recycling, are realized and salicylic follow entirely
Ring, atom utilization is high, and environmental benefit is high.
Specific embodiment
In order to further illustrate the present invention, below with reference to embodiment to a kind of 3,6- dichlorosalicylic acid system provided by the invention
Salicylic complete alternation method is described in detail during standby.
Embodiment 1
138g salicylic acid is put into 5 DEG C of 95% sulfuric acid of 1000g, and 80.0g bromine is slowly added dropwise, heating is added dropwise
To 20 DEG C of heat preservation 2h, 40 DEG C are warming up to, starts to be passed through chlorine, when middle control all generates 5- bromo- 3- chloro-salicylic acid, stops logical chlorine,
It is slowly added to 400g sulfur trioxide, 0.15g iodine is added, maintains 35 DEG C of temperature, starts to be passed through chlorine, it is bromo- that middle control all generates 5-
When 3,6- dichlorosalicylic acid, stopping is passed through chlorine.Reaction solution is poured into ice water, system sulfuric acid concentration is diluted to 30%, filter,
Washing drying obtains the bromo- 3,6- dichlorosalicylic acid 237.8g of 5-.Yield is bromo- 3, the 6- dichlorosalicylic acid content of 75.0%, 5-
90.2%.
Bromo- 3, the 6- dichlorosalicylic acid of 5- is added in the liquid alkaline of 1075g 10%, 50 DEG C is warming up to, until complete by debromination
Molten, nitrogen purging finishes, and 210g tin metal powder is added, and reacts control bromo- 3, the 6- dichlorosalicylic acid of 5- in 1h and is fully converted to 3,
6- dichlorosalicylic acid is separated by filtration metal powder, and filtrate is acidified PH < 1 with 30% sulfuric acid, is cooled to 25 DEG C, filters, and washes, and dries
It is dry to obtain 3,6- dichlorosalicylic acid 168.9g, content 90.1%, debromination conversion ratio 100%, yield 98.0%, by 3,6- bis-
Chloro-salicylic acid is added in 10 times of dimethylbenzene, is warming up to 120 DEG C, keeps the temperature and obtains 3,6- dichlorosalicylic acid fine work, content 99.3%,
Appearance white.
Recrystallization dimethylbenzene 1703g is taken, 10% liquid alkaline of 65g is added and adjusts PH=12-13, liquid separation, water phase is added 0.1g and urges
Agent Raney's nickel is passed through hydrogen at 25 DEG C, maintains pressure 0.2Mpa, reacts 1h, and filtration catalytic agent is acidified PH=2- with hydrochloric acid
3,20 DEG C are cooled to, suction filtration, washing, drying obtain salicylic acid, and conversion ratio 100%, content 99.5%, yield accounts for salicylic acid and feeds intake
Amount 13%.
It takes chloro to finish 30% sulfuric acid 3657g, is added dimethylbenzene 600g, n-butanol 120g, 25 DEG C of stirring 30min liquid separations,
Oil is added to 98% sulfuric acid of 7.2g, heating, maintains 90 DEG C of temperature, solvent dehydration carries out esterification, and end of reaction is warming up to
120 DEG C carry out de- sulfo group reaction.End of reaction distills out dimethylbenzene and n-butanol, and 10% liquid alkaline of 300g is added and carries out alkaline hydrolysis,
Hydrochloric acid is acidified to obtain salicylic acid content 25% and 5 bromosalicylic acid 75% after abjection n-butanol, and total recovery accounts for salicylic acid inventory
5%.
Therefore total recovery is 91.5% under salicylic acid complete alternation.
Embodiment 2
138g salicylic acid is put into 5 DEG C of 95% sulfuric acid of 1000g, is slowly added dropwise and is passed through 81.0g bromination hydrogen, is led to
Enter to finish to be warming up to 20 DEG C of heat preservation 2h, be warming up to 40 DEG C, starts to be passed through chlorine, when middle control all generates 5- bromo- 3- chloro-salicylic acid,
Stop logical chlorine, be slowly added to 400g sulfur trioxide, 0.15g iodine is added, maintain 35 DEG C of temperature, starts to be passed through chlorine, middle control is all
When generating bromo- 3, the 6- dichlorosalicylic acid of 5-, stopping is passed through chlorine.Reaction solution is poured into ice water, system sulfuric acid concentration is diluted to
30%, filtering, washing drying obtain bromo- 3, the 6- dichlorosalicylic acid 238.9g of 5-.Yield is bromo- 3,6-, bis- chlorine water of 75.3%, 5-
Poplar acid content 90.2%.
Bromo- 3, the 6- dichlorosalicylic acid of 5- is added in the ammonium hydroxide of 1075g 10%, 50 DEG C is warming up to, until complete by debromination
Molten, nitrogen purging finishes, and 210g aluminum metal powder is added, and reacts control bromo- 3, the 6- dichlorosalicylic acid of 5- in 1h and is fully converted to 3,
6- dichlorosalicylic acid is separated by filtration metal powder, and filtrate is acidified PH < 1 with 30% sulfuric acid, is cooled to 25 DEG C, filters, and washes, and dries
It is dry to obtain 3,6- dichlorosalicylic acid 169.7g, content 90.1%, debromination conversion ratio 100%, yield 98.1%, by 3,6- bis-
Chloro-salicylic acid is added in 10 times of ortho-xylenes, is warming up to 120 DEG C, heat preservation obtains 3,6- dichlorosalicylic acid fine work, and content is
99.2%, appearance white.
Recrystallization dimethylbenzene 1703g is taken, 10% liquid alkaline of 65g is added and adjusts PH=12-13, liquid separation, water phase is added 0.1g and urges
Agent Raney's nickel is passed through hydrogen at 25 DEG C, maintains pressure 0.2Mpa, reacts 1h, and filtration catalytic agent is acidified PH=2- with hydrochloric acid
3,20 DEG C are cooled to, suction filtration, washing, drying obtain salicylic acid, and conversion ratio 100%, content 99.5%, yield accounts for salicylic acid and feeds intake
Amount 12%.
It takes chloro to finish 30% sulfuric acid 3657g, is added dimethylbenzene 600g, n-butanol 120g, 25 DEG C of stirring 30min liquid separations,
Oil is added to 98% sulfuric acid of 7.2g, heating, maintains 90 DEG C of temperature, solvent dehydration carries out esterification, and end of reaction is warming up to
120 DEG C carry out de- sulfo group reaction.End of reaction distills out dimethylbenzene and n-butanol, and 10% liquid alkaline of 300g is added and carries out alkaline hydrolysis,
Hydrochloric acid is acidified to obtain salicylic acid content 25% and 5 bromosalicylic acid 75% after abjection n-butanol, and total recovery accounts for salicylic acid inventory
5%.
Therefore total recovery is 90.9% under salicylic acid complete alternation.
Embodiment 3
138g salicylic acid is put into 5 DEG C of 95% sulfuric acid of 1000g, and 80.0g bromine is slowly added dropwise, heating is added dropwise
To 20 DEG C of heat preservation 2h, 40 DEG C are warming up to, starts to be passed through chlorine, when middle control all generates 5- bromo- 3- chloro-salicylic acid, stops logical chlorine,
It is slowly added to 400g sulfur trioxide, 0.15g iodine is added, maintains 35 DEG C of temperature, starts to be passed through chlorine, it is bromo- that middle control all generates 5-
When 3,6- dichlorosalicylic acid, stopping is passed through chlorine.Reaction solution is poured into ice water, system sulfuric acid concentration is diluted to 30%, filter,
Washing drying obtains the bromo- 3,6- dichlorosalicylic acid 237.8g of 5-.Yield is bromo- 3, the 6- dichlorosalicylic acid content of 75.0%, 5-
90.2%.
Bromo- 3, the 6- dichlorosalicylic acid of 5- is added in the liquid alkaline of 1075g 10%, 50 DEG C is warming up to, until complete by debromination
Molten, nitrogen purging finishes, and 210g magnesium metal powder is added, and reacts control bromo- 3, the 6- dichlorosalicylic acid of 5- in 1h and is fully converted to 3,
6- dichlorosalicylic acid is separated by filtration metal powder, and filtrate is acidified PH < 1 with 30% sulfuric acid, is cooled to 25 DEG C, filters, and washes, and dries
It is dry to obtain 3,6- dichlorosalicylic acid 170.5g, content 90.1%, debromination conversion ratio 100%, yield 98.1%, by 3,6- bis-
Chloro-salicylic acid is added in 10 times of dimethylbenzene, is warming up to 120 DEG C, keeps the temperature and obtains 3,6- dichlorosalicylic acid fine work, content 99.1%,
Appearance white.
Recrystallization dimethylbenzene 1703g is taken, 10% liquid alkaline of 65g is added and adjusts PH=12-13, liquid separation, water phase is added 0.1g and urges
Agent Raney's nickel is passed through hydrogen at 25 DEG C, maintains pressure 0.2Mpa, reacts 1h, and filtration catalytic agent is acidified PH=2- with hydrochloric acid
3,20 DEG C are cooled to, suction filtration, washing, drying obtain salicylic acid, and conversion ratio 100%, content 99.5%, yield accounts for salicylic acid and feeds intake
Amount 13%.
It takes chloro to finish 30% sulfuric acid 3657g, is added dimethylbenzene 600g, n-butanol 120g, 25 DEG C of stirring 30min liquid separations,
Oil is added to 98% sulfuric acid of 7.2g, heating, maintains 90 DEG C of temperature, solvent dehydration carries out esterification, and end of reaction is warming up to
120 DEG C carry out de- sulfo group reaction.End of reaction distills out dimethylbenzene and n-butanol, and 10% liquid alkaline of 300g is added and carries out alkaline hydrolysis,
Hydrochloric acid is acidified to obtain salicylic acid content 25% and 5 bromosalicylic acid 75% after abjection n-butanol, and total recovery accounts for salicylic acid inventory
5%.
Therefore total recovery is 91.6% under salicylic acid complete alternation.
Embodiment 4
138g salicylic acid is put into 5 DEG C of 95% sulfuric acid of 1000g, is slowly added dropwise and is passed through 81.0g bromination hydrogen, is led to
Enter to finish to be warming up to 20 DEG C of heat preservation 2h, be warming up to 40 DEG C, starts to be passed through chlorine, when middle control all generates 5- bromo- 3- chloro-salicylic acid,
Stop logical chlorine, be slowly added to 400g sulfur trioxide, 0.15g iodine is added, maintain 35 DEG C of temperature, starts to be passed through chlorine, middle control is all
When generating bromo- 3, the 6- dichlorosalicylic acid of 5-, stopping is passed through chlorine.Reaction solution is poured into ice water, system sulfuric acid concentration is diluted to
30%, filtering, washing drying obtain bromo- 3, the 6- dichlorosalicylic acid 238.9g of 5-.Yield is bromo- 3,6-, bis- chlorine water of 75.3%, 5-
Poplar acid content 90.2%.
Bromo- 3, the 6- dichlorosalicylic acid of 5- is added in the liquid alkaline of 1075g 10%, 50 DEG C is warming up to, until complete by debromination
Molten, nitrogen purging finishes, and 210g zinc metal powder is added, and reacts control bromo- 3, the 6- dichlorosalicylic acid of 5- in 1h and is fully converted to 3,
6- dichlorosalicylic acid is separated by filtration metal powder, and filtrate is acidified PH < 1 with 30% sulfuric acid, is cooled to 25 DEG C, filters, and washes, and dries
It is dry to obtain 3,6- dichlorosalicylic acid 169.8g, content 90.1%, debromination conversion ratio 100%, yield 98.4%, by 3,6- bis-
Chloro-salicylic acid is added in 10 times of ortho-xylenes, is warming up to 120 DEG C, heat preservation obtains 3,6- dichlorosalicylic acid fine work, and content is
99.1%, appearance white.
Recrystallization dimethylbenzene 1703g is taken, 10% liquid alkaline of 65g is added and adjusts PH=12-13, liquid separation, water phase is added 0.1g and urges
Agent Raney's nickel is passed through hydrogen at 25 DEG C, maintains pressure 0.2Mpa, reacts 1h, and filtration catalytic agent is acidified PH=2- with hydrochloric acid
3,20 DEG C are cooled to, suction filtration, washing, drying obtain salicylic acid, and conversion ratio 100%, content 99.5%, yield accounts for salicylic acid and feeds intake
Amount 13%.
It takes chloro to finish 30% sulfuric acid 3657g, is added dimethylbenzene 600g, n-butanol 120g, 25 DEG C of stirring 30min liquid separations,
Oil is added to 98% sulfuric acid of 7.2g, heating, maintains 90 DEG C of temperature, solvent dehydration carries out esterification, and end of reaction is warming up to
120 DEG C carry out de- sulfo group reaction.End of reaction distills out dimethylbenzene and n-butanol, and 10% liquid alkaline of 300g is added and carries out alkaline hydrolysis,
Hydrochloric acid is acidified to obtain salicylic acid content 25% and 5 bromosalicylic acid 75% after abjection n-butanol, and total recovery accounts for salicylic acid inventory
5%.
Therefore total recovery is 92.1% under salicylic acid complete alternation.
Embodiment 5
138g salicylic acid is put into 5 DEG C of 95% sulfuric acid of 1000g, and 80.0g bromine is slowly added dropwise, heating is added dropwise
To 20 DEG C of heat preservation 2h, 40 DEG C are warming up to, starts to be passed through chlorine, when middle control all generates 5- bromo- 3- chloro-salicylic acid, stops logical chlorine,
It is slowly added to 400g sulfur trioxide, 0.15g iodine is added, maintains 35 DEG C of temperature, starts to be passed through chlorine, it is bromo- that middle control all generates 5-
When 3,6- dichlorosalicylic acid, stopping is passed through chlorine.Reaction solution is poured into ice water, system sulfuric acid concentration is diluted to 30%, filter,
Washing drying obtains the bromo- 3,6- dichlorosalicylic acid 237.8g of 5-.Yield is bromo- 3, the 6- dichlorosalicylic acid content of 75.0%, 5-
90.2%.
Bromo- 3, the 6- dichlorosalicylic acid of 5- is added in the liquid alkaline of 1075g 10%, 50 DEG C is warming up to, until complete by debromination
Molten, nitrogen purging finishes, and 212g nickel aluminum metal powder is added, and reacts control bromo- 3, the 6- dichlorosalicylic acid of 5- in 1h and converts completely
For 3,6- dichlorosalicylic acid, it is separated by filtration metal powder, filtrate is acidified PH < 1 with 30% sulfuric acid, is cooled to 25 DEG C, filters, water
It washes, drying obtains 3,6- dichlorosalicylic acid 169.6g, and content 90.1%, debromination conversion ratio 100%, yield 97.5% will
3,6- dichlorosalicylic acids are added in 10 times of ortho-xylenes, are warming up to 120 DEG C, heat preservation obtains 3,6- dichlorosalicylic acid fine work, content
It is 99.0%, appearance white.
Recrystallization dimethylbenzene 1703g is taken, 10% liquid alkaline of 65g is added and adjusts PH=12-13, liquid separation, water phase is added 0.1g and urges
Agent Raney's nickel is passed through hydrogen at 25 DEG C, maintains pressure 0.2Mpa, reacts 1h, and filtration catalytic agent is acidified PH=2- with hydrochloric acid
3,20 DEG C are cooled to, suction filtration, washing, drying obtain salicylic acid, and conversion ratio 100%, content 99.5%, yield accounts for salicylic acid and feeds intake
Amount 13%.
It takes chloro to finish 30% sulfuric acid 3657g, is added dimethylbenzene 600g, n-butanol 120g, 25 DEG C of stirring 30min liquid separations,
Oil is added to 98% sulfuric acid of 7.2g, heating, maintains 90 DEG C of temperature, solvent dehydration carries out esterification, and end of reaction is warming up to
120 DEG C carry out de- sulfo group reaction.End of reaction distills out dimethylbenzene and n-butanol, and 10% liquid alkaline of 300g is added and carries out alkaline hydrolysis,
Hydrochloric acid is acidified to obtain salicylic acid content 25% and 5 bromosalicylic acid 75% after abjection n-butanol, and total recovery accounts for salicylic acid inventory
5%.
Therefore total recovery is 91.1% under salicylic acid complete alternation.
Embodiment 6
138g salicylic acid is put into 5 DEG C of 95% sulfuric acid of 1000g, and 80.0g bromine is slowly added dropwise, heating is added dropwise
To 20 DEG C of heat preservation 2h, 40 DEG C are warming up to, starts to be passed through chlorine, when middle control all generates 5- bromo- 3- chloro-salicylic acid, stops logical chlorine,
It is slowly added to 400g sulfur trioxide, 0.15g iodine is added, maintains 35 DEG C of temperature, starts to be passed through chlorine, it is bromo- that middle control all generates 5-
When 3,6- dichlorosalicylic acid, stopping is passed through chlorine.Reaction solution is poured into ice water, system sulfuric acid concentration is diluted to 30%, filter,
Washing drying obtains the bromo- 3,6- dichlorosalicylic acid 237.8g of 5-.Yield is bromo- 3, the 6- dichlorosalicylic acid content of 75.0%, 5-
90.2%.
Bromo- 3, the 6- dichlorosalicylic acid of 5- is added in the liquid alkaline of 1075g 10%, 50 DEG C is warming up to, until complete by debromination
Molten, nitrogen purging finishes, and 211g tin aluminum zinc metal powder is added, and it is complete to react control bromo- 3, the 6- dichlorosalicylic acid of 5- in 1h
It is converted into 3,6- dichlorosalicylic acid, is separated by filtration metal powder, filtrate is acidified PH < 1 with 30% sulfuric acid, is cooled to 25 DEG C, it filters,
Washing dries and obtains 3,6- dichlorosalicylic acid 168.5g, content 90.1%, debromination conversion ratio 100%, yield 96.9%,
3,6- dichlorosalicylic acid is added in 10 times of dimethylbenzene, is warming up to 120 DEG C, heat preservation obtains 3,6- dichlorosalicylic acid fine work, content
It is 99.0%, appearance white.
Recrystallization dimethylbenzene 1703g is taken, 10% liquid alkaline of 65g is added and adjusts PH=12-13, liquid separation, water phase is added 0.1g and urges
Agent Raney's nickel is passed through hydrogen at 25 DEG C, maintains pressure 0.2Mpa, reacts 1h, and filtration catalytic agent is acidified PH=2- with hydrochloric acid
3,20 DEG C are cooled to, suction filtration, washing, drying obtain salicylic acid, and conversion ratio 100%, content 99.5%, yield accounts for salicylic acid and feeds intake
Amount 13%.
It takes chloro to finish 30% sulfuric acid 3657g, is added dimethylbenzene 600g, n-butanol 120g, 25 DEG C of stirring 30min liquid separations,
Oil is added to 98% sulfuric acid of 7.2g, heating, maintains 90 DEG C of temperature, solvent dehydration carries out esterification, and end of reaction is warming up to
120 DEG C carry out de- sulfo group reaction.End of reaction distills out dimethylbenzene and n-butanol, and 10% liquid alkaline of 300g is added and carries out alkaline hydrolysis,
Hydrochloric acid is acidified to obtain salicylic acid content 25% and 5 bromosalicylic acid 75% after abjection n-butanol, and total recovery accounts for salicylic acid inventory
5%.
Therefore total recovery is 90.7% under salicylic acid complete alternation.
Embodiment 7
Recrystallization dimethylbenzene 8000g is taken, 10% liquid alkaline of 308g is added and adjusts PH=12-13, liquid separation, 0.5g is added in water phase
Catalyst Raney's nickel is passed through hydrogen at 25 DEG C, maintains pressure 0.2Mpa, reacts 1h, and filtration catalytic agent is acidified PH=with hydrochloric acid
2-3 is cooled to 20 DEG C, filters, washes, drying obtains salicylic acid, conversion ratio 100%, content 99.5%, appearance white.
It takes chloro to finish 30% sulfuric acid 1000g, dimethylbenzene 200g, n-butanol 40g, 25 DEG C of stirring 30min liquid separations, oil is added
It is added to 98% sulfuric acid of 2.4g, is heated up, maintains 90 DEG C of temperature, solvent dehydration carries out esterification, and end of reaction is warming up to 120
DEG C carry out de- sulfo group reaction.End of reaction distills out dimethylbenzene and n-butanol, and 10% liquid alkaline of 100g is added and carries out alkaline hydrolysis, abjection
Hydrochloric acid is acidified to obtain salicylic acid 25% and 5 bromosalicylic acid 75%, appearance white after n-butanol.
Salicylic acid after hydrodehalogenation and sulfonated bodies are taken off into the salicylic acid of sulfo group and 5 bromosalicylic acid 138g puts into 5 DEG C
In 95% sulfuric acid of 1000g, 67.2g bromine is slowly added dropwise, is added dropwise and is warming up to 20 DEG C of heat preservation 2h, be warming up to 40 DEG C, start to lead to
Enter chlorine, when middle control all generates 5- bromo- 3- chloro-salicylic acid, stops logical chlorine, be slowly added to 400g sulfur trioxide, 0.15g is added
Iodine maintains 35 DEG C of temperature, starts to be passed through chlorine, when middle control all generates 5- bromo- 3,6- dichlorosalicylic acid, stops being passed through chlorine.
Reaction solution is poured into ice water, system sulfuric acid concentration is diluted to 30%, and filtering, washing drying obtain bromo- 3,6-, bis- chloro-salicyloyl of 5-
Sour 215.2g.Yield is bromo- 3, the 6- dichlorosalicylic acid content 90.2% of 75.1%, 5-.
Bromo- 3, the 6- dichlorosalicylic acid of 5- is added in the liquid alkaline of 1075g 10%, 50 DEG C is warming up to, until complete by debromination
Molten, nitrogen purging finishes, and 212g nickel aluminum metal powder is added, and reacts control bromo- 3, the 6- dichlorosalicylic acid of 5- in 1h and converts completely
For 3,6- dichlorosalicylic acid, it is separated by filtration metal powder, filtrate is acidified PH < 1 with 30% sulfuric acid, is cooled to 25 DEG C, filters, water
It washes, drying obtains 3,6- dichlorosalicylic acid 152.0g, and content 90.1%, debromination conversion ratio 100%, yield 97.5% will
3,6- dichlorosalicylic acids are added in 10 times of ortho-xylenes, are warming up to 120 DEG C, heat preservation obtains 3,6- dichlorosalicylic acid fine work, content
It is 99.0%, appearance white.
Embodiment 8
Recrystallization ortho-xylene 8000g is taken, 10% liquid alkaline of 308g is added and adjusts PH=12-13, liquid separation, water phase is added
0.5g catalyst palladium carbon is passed through hydrogen at 45 DEG C, maintains pressure 0.3Mpa, reacts 0.5h, and filtration catalytic agent is acidified with hydrochloric acid
PH=2-3 is cooled to 20 DEG C, filters, washes, drying obtains salicylic acid, conversion ratio 100%, content 99.5%, appearance white.
It takes chloro to finish 30% sulfuric acid 1000g, toluene 200g, isoamyl alcohol 40g, 25 DEG C of stirring 30min liquid separations, oily phase is added
98% sulfuric acid of 2.4g is added, heating maintains 80 DEG C of temperature, and solvent dehydration carries out esterification, and end of reaction is warming up to 120 DEG C
Carry out de- sulfo group reaction.End of reaction distills out toluene and isoamyl alcohol, and 10% liquid alkaline of 100g is added and carries out alkaline hydrolysis, deviates from isoamyl
Hydrochloric acid is acidified to obtain salicylic acid 25% and 5 bromosalicylic acid 75%, appearance white after alcohol.
Salicylic acid after hydrodehalogenation and sulfonated bodies are taken off into the salicylic acid of sulfo group and 5 bromosalicylic acid 138g puts into 5 DEG C
In 95% sulfuric acid of 1000g, 67.5g bromine is slowly added dropwise, is added dropwise and is warming up to 20 DEG C of heat preservation 2h, be warming up to 40 DEG C, start to lead to
Enter chlorine, when middle control all generates 5- bromo- 3- chloro-salicylic acid, stops logical chlorine, be slowly added to 400g sulfur trioxide, 0.15g is added
Iodine maintains 35 DEG C of temperature, starts to be passed through chlorine, when middle control all generates 5- bromo- 3,6- dichlorosalicylic acid, stops being passed through chlorine.
Reaction solution is poured into ice water, system sulfuric acid concentration is diluted to 30%, and filtering, washing drying obtain bromo- 3,6-, bis- chloro-salicyloyl of 5-
Sour 215.2g.Yield is bromo- 3, the 6- dichlorosalicylic acid content 90.2% of 75.1%, 5-.
Bromo- 3, the 6- dichlorosalicylic acid of 5- is added in the liquid alkaline of 1075g 10%, 50 DEG C is warming up to, until complete by debromination
Molten, nitrogen purging finishes, and 212g aluminum metal powder is added, and reacts control bromo- 3, the 6- dichlorosalicylic acid of 5- in 1h and is fully converted to 3,
6- dichlorosalicylic acid is separated by filtration metal powder, and filtrate is acidified PH < 1 with 30% sulfuric acid, is cooled to 25 DEG C, filters, and washes, and dries
It is dry to obtain 3,6- dichlorosalicylic acid 151.5g, content 90.0%, debromination conversion ratio 100%, yield 97.3%, by 3,6- bis-
Chloro-salicylic acid is added in 10 times of ortho-xylenes, is warming up to 120 DEG C, heat preservation obtains 3,6- dichlorosalicylic acid fine work, and content is
99.1%, appearance white.
Comparative example
138g salicylic acid is put into 5 DEG C of 95% sulfuric acid of 1000g, is slowly added dropwise and is passed through 81.0g bromination hydrogen, is led to
Enter to finish to be warming up to 20 DEG C of heat preservation 2h, be warming up to 40 DEG C, starts to be passed through chlorine, when middle control all generates 5- bromo- 3- chloro-salicylic acid,
Stop logical chlorine, be slowly added to 400g sulfur trioxide, 0.15g iodine is added, maintain 35 DEG C of temperature, starts to be passed through chlorine, middle control is all
When generating bromo- 3, the 6- dichlorosalicylic acid of 5-, stopping is passed through chlorine.Reaction solution is poured into ice water, system sulfuric acid concentration is diluted to
30%, filtering, washing drying obtain bromo- 3, the 6- dichlorosalicylic acid 238.9g of 5-.Yield is bromo- 3,6-, bis- chlorine water of 75.3%, 5-
Poplar acid content 90.2%.
Bromo- 3, the 6- dichlorosalicylic acid of 5- is added in the ammonium hydroxide of 1075g 10%, 50 DEG C is warming up to, until complete by debromination
Molten, nitrogen purging finishes, and 210g aluminum metal powder is added, and reacts control bromo- 3, the 6- dichlorosalicylic acid of 5- in 1h and is fully converted to 3,
6- dichlorosalicylic acid is separated by filtration metal powder, and filtrate is acidified PH < 1 with 30% sulfuric acid, is cooled to 25 DEG C, filters, and washes, and dries
It is dry to obtain 3,6- dichlorosalicylic acid 169.7g, content 90.1%, debromination conversion ratio 100%, yield 98.1%, by 3,6- bis-
Chloro-salicylic acid is added in 10 times of ortho-xylenes, is warming up to 120 DEG C, heat preservation obtains 3,6- dichlorosalicylic acid fine work, and content is
99.2%, appearance white.
It is computed, salicylic acid total recovery is 73.6%.
By above-described embodiment and comparative example it is found that preparation method provided by the invention, salicylic utilization rate have obtained very
Big raising.
The above description of the embodiment is only used to help understand the method for the present invention and its core ideas.It should be pointed out that pair
For those skilled in the art, without departing from the principle of the present invention, the present invention can also be carried out
Some improvements and modifications, these improvements and modifications also fall within the scope of protection of the claims of the present invention.
Claims (10)
1. one kind 3, salicylic complete alternation method in 6- dichlorosalicylic acid preparation process, which comprises the following steps:
A) salicylic acid and bromine or hydrogen bromide, are reacted in concentrated sulfuric acid, obtain 5 bromosalicylic acid；
B) 5 bromosalicylic acid and chlorine carry out chlorination reaction, obtain bromo- 3, the 6- dichlorosalicylic acid of 5-；
C) bromo- 3, the 6- dichlorosalicylic acid of 5- carries out debromination, it is thick to obtain 3,6- dichlorosalicylic acid under the effect of the catalyst
Product；
D) 3,6- dichlorosalicylic acid crude product is recrystallized in dimethylbenzene or toluene, is obtained 3,6- dichlorosalicylic acid sterling and is contained
Impurity solvent；The impurity includes 3- chloro-salicylic acid, 3,5- dichlorosalicylic acid and the bromo- 6- chloro-salicylic acid of 3-；
E) for the impure solvent through alkali cleaning, liquid separation obtains water phase, and catalyst is added in water phase, carries out hydrodehalogenation reaction, mistake
Catalyst is filtered out, acidification of filtrate obtains salicylic acid, reuse to step A).
2. the method according to claim 1, wherein the step E) catalyst be palladium carbon or Raney's nickel.
3. the method according to claim 1, wherein the step E) in, the mass ratio of catalyst and water phase is
0.001~0.02:1.
4. the method according to claim 1, wherein the step E) temperature of hydrodehalogenation reaction is 20~
100 DEG C, the time is 0.5~5h, and pressure is 0.1~1MPa.
5. the method according to claim 1, wherein the step B) specifically:
B1) 5 bromosalicylic acid and chlorine carry out chlorination reaction, obtain the bromo- 3- chloro-salicylic acid of 5-；Then sulfur trioxide and iodine is added,
Reaction obtains the bromo- 3,6- dichlorosalicylic acid of 5-；
B2 it is 20%~40% that system, which) is diluted to sulfuric acid concentration, through cooling, filtering, washing, drying, obtains bromo- 3, the 6- dichloro of 5-
Salicylic acid sterling and sulfuric acid phase；
B3) through solvent extraction and separation, oil is added to the de- sulfo group of concentrated sulfuric acid esterification and obtains salicylate and 5 bromosalicylic acid sulfuric acid phase
Ester；
B4 after solvent) is distilled off, alkaline hydrolysis, dealcoholysis, acidification, suction filtration, washing, drying is carried out, salicylic acid and 5- bromine water poplar are obtained
Acid, reuse to step A).
6. according to the method described in claim 5, the it is characterized in that, step b3) in solvent include toluene and dimethylbenzene
In any one and C1~8 alcohol compound.
7. according to the method described in claim 6, it is characterized in that, the molar ratio of the toluene or dimethylbenzene and sulfuric acid is 1:(1
~10)；The alcohol compound and toluene of C1~8 or the volume ratio of dimethylbenzene are 1:(3~10).
8. according to the method described in claim 5, the it is characterized in that, step b3) in, the temperature of esterification is 80~110 DEG C,
The temperature of de- sulfo group is 110~160 DEG C.
9. the method according to claim 1, wherein the step C) specifically:
Bromo- 3, the 6- dichlorosalicylic acid of 5- under the action of metal powder, carries out debromination, obtains 3,6- under alkaline condition
Dichlorosalicylic acid crude product.
10. according to the method described in claim 9, it is characterized in that, the metal powder is in tin, aluminium, zinc, nickel, iron and magnesium
Any one or more.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101348420A (en) * | 2008-09-12 | 2009-01-21 | 湖南利洁生物化工有限公司 | Hydrogenation dehalogenation method of halogenated alkyl phenol coumpound |
| CN106659162A (en) * | 2014-06-04 | 2017-05-10 | 孟山都技术公司 | 3,6-dichlorosalicylic acid compounds and related synthetic processes |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101348420A (en) * | 2008-09-12 | 2009-01-21 | 湖南利洁生物化工有限公司 | Hydrogenation dehalogenation method of halogenated alkyl phenol coumpound |
| CN106659162A (en) * | 2014-06-04 | 2017-05-10 | 孟山都技术公司 | 3,6-dichlorosalicylic acid compounds and related synthetic processes |
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