CN106008379A - Preparation method of benzotriazole light stabilizer - Google Patents
Preparation method of benzotriazole light stabilizer Download PDFInfo
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- CN106008379A CN106008379A CN201610374220.XA CN201610374220A CN106008379A CN 106008379 A CN106008379 A CN 106008379A CN 201610374220 A CN201610374220 A CN 201610374220A CN 106008379 A CN106008379 A CN 106008379A
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- 0 *C(CC(*)=C1O)C=C1N=Nc(cccc1)c1[N+](*)[O-] Chemical compound *C(CC(*)=C1O)C=C1N=Nc(cccc1)c1[N+](*)[O-] 0.000 description 7
- GEYOCULIXLDCMW-UHFFFAOYSA-N Nc1ccccc1N Chemical compound Nc1ccccc1N GEYOCULIXLDCMW-UHFFFAOYSA-N 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D249/00—Heterocyclic compounds containing five-membered rings having three nitrogen atoms as the only ring hetero atoms
- C07D249/16—Heterocyclic compounds containing five-membered rings having three nitrogen atoms as the only ring hetero atoms condensed with carbocyclic rings or ring systems
- C07D249/18—Benzotriazoles
- C07D249/20—Benzotriazoles with aryl radicals directly attached in position 2
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D487/00—Heterocyclic compounds containing nitrogen atoms as the only ring hetero atoms in the condensed system, not provided for by groups C07D451/00 - C07D477/00
- C07D487/02—Heterocyclic compounds containing nitrogen atoms as the only ring hetero atoms in the condensed system, not provided for by groups C07D451/00 - C07D477/00 in which the condensed system contains two hetero rings
- C07D487/04—Ortho-condensed systems
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- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention discloses a preparation method of a benzotriazole ultraviolet light stabilizer. The method comprises the following steps: adding an azo dye intermediate represented by formula I to hydrazine hydrate, carrying out reduction to form an intermediate nitrogen oxide represented by formula II, and reducing the intermediate nitrogen oxide represented by formula II with hydrogen to prepare the benzotriazole ultraviolet light stabilizer represented by formula III, wherein the formula I, the formula II and the formula III are respectively shown in the description, and R<'> in the formulas is C(CH3)3 or CH3. The preparation method allows wastewater generated in the invention to be environmentally-friendly.
Description
Technical field
The present invention relates to ultra-violet absorption field, particularly to the preparation method of a kind of benzotriazole light stabilizer.
Background technology
Plastics and other macromolecular materials, be exposed under daylight or high-energy ray, owing to absorbing UV energy, and meeting
There is photooxidative degradation, cause depolymerization to deteriorate, hydraulic performance decline.UV absorbent is a kind of light stabilizer, its
The ultraviolet part in sunlight and fluorescence light source can be absorbed, and itself does not changes.At plastics and other macromolecular materials
Optionally absorb high-octane ultraviolet after middle addition UV absorbent, be allowed to become harmless energy and discharge or disappear
Consumption.Benzotriazole is one of common UV absorbent, shown in following reaction equation A of its stable mechanism:
Reaction equation A.
Benzotriazole light stabilizer, also referred to as benzotriazole light stabilizer, its absorbance is also than other ultraviolet
Absorbent wants height, and it has, and oil resistant, resistance to variable color, volatility be low, the little advantage good with polymer compatibility of toxicity,
It is widely used in synthetic material and goods.At present, conventional reducing process prepares benzotriazole light stabilizer, i.e. adjacent nitro
Aniline (or its substituent) makes diazonium salt solution through diazo-reaction, is then allowed to make intermediate dye with alkyl phenol coupling
Material, finally becomes final products by its reduction closed loop；It reacts shown in following reaction equation B:
Reaction equation B.
At present, the synthetic technology of azo dye intermediate is mature on the whole, and reduction technique is always the heat of chemical circles research
Point, easily occurs azo bond fracture to generate by-product aminated compounds when its difficult point is azo dye intermediate reduction.Azo contaminates
Material intermediate reduction closed loop is that the mechanism of BTA compounds is not yet fully apparent from, but the sight gained universal acceptance at present
Point is: azo dye intermediate may firstly generate hydrazine class compound, and primary response (ring-closure reaction) is then hydrazine class compound
Intramolecular dehydration generates BTA nitrogen oxides and is further reduced into final products, and side reaction is then hydrazine class compound
Being split into two molecular amine, two molecular amine can react with other materials in reaction system；Its primary response and side reaction are as follows
Shown in reaction equation C:
Reaction equation C.
The Chinese patent that application notification number is CN104327002A, Shen Qing Publication day is on February 4th, 2015 discloses one
Planting the production technology of Benzotriazole Ultraviolet Stabilizer, in this production technology, azo dye intermediate reduction closed loop uses as follows
Method: in former intermediate dye synthetic system, is directly added into hydrazine hydrate and carries out a reduction, in the purification system of a reduction
Add zinc powder and carry out two step reduction, purify and get final product.It is disadvantageous in that, uses zinc reduction to produce substantial amounts of useless containing zinc
Water, environmental pollution is serious.
The Chinese patent that application notification number is CN104610179A, Shen Qing Publication day is on May 13rd, 2015 discloses
The method for continuously synthesizing of a kind of Benzotriazole Ultraviolet Stabilizer, loads fixed bed reactors by reduced form solid catalyst
In；By compound shown in Formulas I and alkali dissolution in a solvent, it is 0.015～300h at volume space velocity-1Under conditions of persistently lead to
Entering fixed bed reactors, and be passed through hydrogen, heating, making Hydrogen Vapor Pressure in fixed bed reactors is 0.1～10MPa, temperature
At 40～220 DEG C；Reactant liquor continue from fixed bed reactors lower end flow out, the reactant liquor of outflow is cooled, gas-liquid separation,
Liquid filters, filtrate steaming removal solvent, and purification to obtain final product.It is disadvantageous in that, this method needs to enter on a fixed bed
Row test, its reaction condition is the most harsh, and on large-scale production, application has certain limitation.
United States Patent (USP) US4230867 discloses the preparation method of a kind of 2-aryl-2H-benzotriazole, in reduced pressure
Under in adjacent nitroazobenzene, be passed through H continuously2Carry out catalytic reaction.It is disadvantageous in that, research finds, this hydrogenation
The reduction of reducing process is wayward, and it is readily obtained byproduct of reaction.
Summary of the invention
It is an object of the invention to provide the preparation method of a kind of benzotriazole light stabilizer, which solve the ring that waste water garbage causes
Environment pollution problem, has the effect of the waste water more environmental protection of generation.
The above-mentioned technical purpose of the present invention has the technical scheme that
The preparation method of a kind of benzotriazole light stabilizer, comprises the following steps:
Step 1: azo dye intermediate shown in formula I, alkali and the first solvent are mixed, adds hydrazine hydrate reduction reaction；
Step 2: mixed solution step 1 obtained carries out purifying for the first time, obtains the intermediate nitrogen oxides as shown in Formula II
Solution；
Step 3: the solution of the intermediate nitrogen oxides as shown in Formula II step 2 obtained and catalyst mixing, is passed through hydrogen
Reduction reaction；
Step 4: mixed solution step 3 obtained carries out crystallize process, obtains the benzotriazole light as shown in formula III stable
The crude product of agent；
Step 5: crude product step 4 obtained and the mixing of the second solvent, carries out second time and purifies, obtain highly purified such as formula III
Shown benzotriazole light stabilizer；
Wherein, Formulas I is:
Formula II is:
Formula III is:
Wherein, described R ' is C (CH3)3Or CH3。
More preferably: in described step 1, based on molal weight, described hydrazine hydrate and azo shown in formula I
The amount ratio of dyestuff intermediate is 0.5～1.0: 1；Described hydrazine hydrate uses the mode being slowly added dropwise under controlled temperature conditions to add to body
In system.
More preferably: in described step 1, alkali selects sodium hydroxide or potassium hydroxide；Based on molal weight, institute
The amount ratio stating alkali and azo dye intermediate shown in formula I is 0.5～1.5: 1；Described first solvent is by 80～100wt%
Aromatic solvent and 0～20wt% the 3rd solvent composition, described 3rd solvent be selected from petroleum ether or C3～C4Ketone or C1～C4Alcohol；
By weight, the amount ratio of described first solvent and azo dye intermediate shown in formula I is 1～20: 1；
In described step 1, the reaction of described hydrazine hydrate reduction is carried out at 60～80 DEG C, and its reaction directing terminal is shown in formula I
The residual quantity of azo dye intermediate is less than the 0.5wt% of its initial inventory.
More preferably: in described step 2, the step purified for the first time is: with mixing that acid neutralization procedure 1 obtains
Close solution；Isolating oil phase, oil phase, through washing, obtains the solution of intermediate nitrogen oxides as shown in Formula II.
More preferably: described acid is sulphuric acid or hydrochloric acid；System pH after neutralizing with acid is 6～7.
More preferably: in described step 3, by weight, described catalyst and azo dye shown in formula I
The amount ratio of intermediate is 1%～5%: 1, and Pt/C selected by described catalyst.
More preferably: in described step 3, the consumption of described hydrogen is controlled by the Hydrogen Vapor Pressure of system, described
During hydrogen reducing, Hydrogen Vapor Pressure perseverance is 0.5～0.8MPa；Hydrogen reducing reaction is carried out at 50～75 DEG C, and it reacts directing terminal
It is less than the 0.1wt% of its initial amount less than 0.05MPa/min and/or the intermediate nitrogen oxides as shown in Formula II for hydrogen-sucking amount.
More preferably: in described step 4, the step that crystallize processes is: crosses and filters catalyst；Take reducing solution fall
Temperature, to 0～10 DEG C, separates out solid, and the pH to 8.5～9.5 of regulation aqueous phase separates out solid, merges two solids, obtain such as formula
The crude product of the benzotriazole light stabilizer shown in III.
More preferably: in described step 5, second time purifies and uses crystallisation by cooling method, its second solvent used
Aromatic solvent and the 4th solvent of 50～80wt% by 20～50wt% form, and C selected by described 4th solvent3～C4Ketone or C1～C4
Alcohol.
More preferably: described aromatic solvent selects toluene or dimethylbenzene.
In sum, the method have the advantages that
1. the present invention uses two stage reduction methods, and its first step uses hydrazine hydrate to be reducing agent, and second step uses hydrogenation method reduction, and it is main
The material that reaction generates is only major product, water and nitrogen, its waste water more environmental protection produced, and has fewer environmental impacts；It produces
Raw waste water only needs i.e. to can reach discharging standards, energy-saving and emission-reduction by simple process；
2. the present invention first carries out a reduction by hydrazine hydrate method to raw material, can reduce chain carrier with hydrazine hydrate for reducing agent, slow down
Response speed, reduces the side reaction that relatively unstable azo dye intermediate shown in formula I produces；It addition, such as formula
Intermediate nitrogen oxides shown in II is less to the sensitivity of reducing condition, is difficult to open loop again and generates amine by-product, and it can
It is reduced into product under the strongest hydroconversion condition；By two kinds of reducing agents with the use of, the increase of side reaction can be reduced,
Improve yield, reduce and pollute；Two steps use hydrogenation method reduction simultaneously, and hydrogen can be by the air in system and the air in solvent
Discharge, reduce reaction substrate or the probability of product oxidation, its purity improving product further and content；
3. the present invention uses raw material, solvent, catalyst, pH condition and consumption thereof are all tested through large-scale production, in this condition
The situation of lower catalyst poisoning almost can be avoided completely, and has preferable large-scale production prospect；
4., in the sample that prepared by the present invention, the purity of crude product is minimum respectively reaches 92.3%；And the yield of sterling and minimum point of purity
Not can reach 89.2% and 98.3%.
Detailed description of the invention
This specific embodiment is only explanation of the invention, and it is not limitation of the present invention, and those skilled in the art are reading
As required the present embodiment can be made after complete this specification and there is no the amendment of creative contribution, but as long as in the power of the present invention
All protected by Patent Law in profit claimed range.
Embodiment 1-6: the preparation method of benzotriazole light stabilizer, comprises the steps:
Step 1: add azo dye intermediate shown in formula I, alkali, the first solvent in reactor；Controlling temperature is 60～80 DEG C,
It is added dropwise over hydrazine hydrate, time for adding at least 30 minutes slowly, stirs 1～4 hour；Sampling HPLC detection, such as Formulas I
The residual quantity of shown azo dye intermediate is less than the 0.5wt% of its initial inventory, and hydrazine hydrate reduction has reacted；
Step 2: addition sulphuric acid (or hydrochloric acid) is neutralized to the pH of system in the mixed solution that step 1 obtains is 6～7, stands and divides
Layer takes oil phase, and oil phase obtains the solution of the intermediate nitrogen oxides as shown in Formula II after washing；
Step 3: the solution of the intermediate nitrogen oxides as shown in Formula II step 2 obtained moves on in autoclave, adds catalysis
Agent Pt/C, is passed through hydrogen；Controlling reaction temperature is 50～65 DEG C and to adjust Hydrogen Vapor Pressure be 0.5～0.8MPa (constant), when
Hydrogen-sucking amount is less than 0.05MPa/min, is warming up to 75 DEG C and is incubated 0.5～3 hour, and hydrogen reducing has reacted；
Step 4: mixed solution Filtration of catalyst step 3 obtained, is cooled to reducing solution 5～10 DEG C and separates out solid, point
Go out aqueous phase and regulate its pH to 8.5～9.5, separating out solid；Merge two solids, obtain as shown in formula III and three nitrogen
The crude product of azole UV absorbent；
Step 5: add part the second solvent in the crude product that step 4 obtains, be warming up to 50～75 DEG C and be incubated 0.5～2 hour,
It is incubated and is slowly added to remaining second solvent, to system close to molten clear or lucky molten clear (range estimation), after heat filtering, take filtrate
It is cooled to 0～10 DEG C, collects the solid separated out, obtain highly purified benzotriazole light stabilizer as shown in formula III；
Wherein, the raw material information of embodiment 1 to 6 is as shown in table 1, and the consumption of raw material is with its active ingredient.
Gather step 4 obtains in embodiment 1 to 6 crude product and the high purity product information that step 5 obtains respectively, produce
Product information result is as shown in table 3；Wherein content and purity use the test of HPLC method.
The raw material information statistics of table 1 embodiment 1-6
The preparation method of benzotriazole light stabilizer, comprises the steps:
Step 1: add azo dye intermediate shown in formula I, alkali, the first solvent in reactor；Controlling temperature is 60～80 DEG C,
It is added dropwise over hydrazine hydrate, time for adding at least 30 minutes slowly, stirs 1～4 hour；Sampling HPLC detection, such as Formulas I
The residual quantity of shown azo dye intermediate is less than the 0.5wt% of its initial inventory, and hydrazine hydrate reduction has reacted；
Step 2: addition sulphuric acid (or hydrochloric acid) is neutralized to the pH of system in the mixed solution that step 1 obtains is 6～7, stands and divides
Layer takes oil phase, and oil phase obtains the solution of the intermediate nitrogen oxides as shown in Formula II after washing；
Step 3: the solution of the intermediate nitrogen oxides as shown in Formula II step 2 obtained moves on in autoclave or reduction kettle,
Then by catalyst Pt/C use water making beating, suck in reduction kettle by vacuum, open nitrogen valve (permanent to pressure 0.5～0.8MPa
Fixed), being warming up to 50～75 DEG C of reactions to reaction directing terminal is that hydrogen-sucking amount is less than 0.05MPa/min, HPLC detection such as Formula II
Shown intermediate nitrogen oxides is less than the 0.1wt% of its initial amount, and hydrogen reducing has reacted；
Step 4: be slowly vented by reduction kettle, is filled with 0.1～0.5MPa nitrogen, Filtration of catalyst；Before filtering, point water still is used
Nitrogen is replaced, and pipeline preheats, and filters end steam and catalyst blowback is entered in reduction kettle；
Material stands 0.5～1 hour, separates lower floor's aqueous phase and extremely neutralizes in still, be cooled to 0～5 DEG C with chilled brine, is centrifuged and is consolidated
Body；The pH to 8.5～9.5 of regulation mother solution, separates out solid；Merge two solids, obtain the benzo three as shown in formula III
The crude product of azole light stabilizer；
Step 5: add crude product and part the second solvent that step 4 obtains in reactor, is warming up to 50～75 DEG C and is incubated at least
1 hour, be incubated and be slowly added to remaining second solvent, to close to molten clearly or close to molten clearly, heat filtering takes filtrate and is down to
0～10 DEG C, collect the solid separated out, obtain highly purified benzotriazole light stabilizer as shown in formula III；
Wherein, the raw material information of embodiment 5 to 8 is as shown in table 2, and the consumption of raw material is with its active ingredient.
Gather step 4 obtains in embodiment 5 to 8 crude product and the high purity product information that step 5 obtains respectively, produce
Product information result is as shown in table 3；Wherein content and purity use the test of HPLC method.
The raw material information statistics of table 2 embodiment 5-12
The product information statistics of table 3 embodiment 1-12
Claims (10)
1. the preparation method of a benzotriazole light stabilizer, it is characterised in that comprise the following steps:
Step 1: azo dye intermediate shown in formula I, alkali and the first solvent are mixed, adds hydrazine hydrate reduction
Reaction；
Step 2: mixed solution step 1 obtained carries out purifying for the first time, obtains the intermediate as shown in Formula II
The solution of nitrogen oxides；
Step 3: the solution of the intermediate nitrogen oxides as shown in Formula II that step 2 is obtained and catalyst mixing,
It is passed through hydrogen reducing reaction；
Step 4: mixed solution step 3 obtained carries out crystallize process, obtains the benzotriazole as shown in formula III
The crude product of class light stabilizer；
Step 5: crude product step 4 obtained and the mixing of the second solvent, carries out second time and purifies, obtain highly purified
Benzotriazole light stabilizer as shown in formula III；
Wherein, Formulas I is:
Formula II is:
Formula III is:
Wherein, described R ' is C (CH3)3Or CH3。
The preparation method of benzotriazole light stabilizer the most according to claim 1, it is characterised in that described
In step 1, based on molal weight, described hydrazine hydrate and the amount ratio of azo dye intermediate shown in formula I
It is 0.5～1.0: 1；Described hydrazine hydrate uses the mode being slowly added dropwise under controlled temperature conditions to add to system.
The preparation method of benzotriazole light stabilizer the most according to claim 1, it is characterised in that described
In step 1, alkali selects sodium hydroxide or potassium hydroxide；Based on molal weight, described alkali and shown in formula I
The amount ratio of azo dye intermediate is 0.5～1.5: 1；
Described first solvent selects the aromatic solvent of 80～100wt% and the 3rd solvent composition of 0～20wt%, and described the
Three solvents are selected from petroleum ether or C3～C4Ketone or C1～C4Alcohol；By weight, described first solvent and shown in formula I
The amount ratio of azo dye intermediate be 1～20: 1；
In described step 1, the reaction of described hydrazine hydrate reduction is carried out at 60～80 DEG C, and its reaction directing terminal is such as formula
The residual quantity of the azo dye intermediate shown in I is less than the 0.5wt% of its initial inventory.
The preparation method of benzotriazole light stabilizer the most according to claim 1, it is characterised in that described
In step 2, the step purified for the first time is: the mixed solution obtained with acid neutralization procedure 1；Isolate oil phase,
Oil phase, through washing, obtains the solution of intermediate nitrogen oxides as shown in Formula II.
The preparation method of benzotriazole light stabilizer the most according to claim 4, it is characterised in that described
Acid is sulphuric acid or hydrochloric acid；System pH after neutralizing with acid is 6～7.
The preparation method of benzotriazole light stabilizer the most according to claim 1, it is characterised in that described
In step 3, by weight, the amount ratio of described catalyst and azo dye intermediate shown in formula I is
1%～5%: 1, Pt/C selected by described catalyst.
The preparation method of benzotriazole light stabilizer the most according to claim 1, it is characterised in that described
In step 3, the consumption of described hydrogen is controlled by the Hydrogen Vapor Pressure of system, Hydrogen Vapor Pressure during described hydrogen reducing
Perseverance is 0.5～0.8MPa；Hydrogen reducing reaction is carried out at 50～75 DEG C, and its reaction directing terminal is that hydrogen-sucking amount is low
The 0.1wt% of its initial amount it is less than in 0.05MPa/min and/or the intermediate nitrogen oxides as shown in Formula II.
The preparation method of benzotriazole light stabilizer the most according to claim 1, it is characterised in that described
In step 4, the step that crystallize processes is: crosses and filters catalyst；Take reducing solution and be cooled to 0～10 DEG C, separate out
Solid, the pH to 8.5～9.5 of regulation aqueous phase separates out solid, merges two solids, obtain as shown in formula III
The crude product of benzotriazole light stabilizer.
The preparation method of benzotriazole light stabilizer the most according to claim 1, it is characterised in that described
In step 5, second time purify use crystallisation by cooling method, its second solvent used by 20～50wt% fragrance
Race's solvent and the 4th solvent composition of 50～80wt%, C selected by described 4th solvent3～C4Ketone or C1～C4Alcohol.
10. according to the preparation method of the benzotriazole light stabilizer described in claim 3 or 9, it is characterised in that
Described aromatic solvent selects toluene or dimethylbenzene.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106749059A (en) * | 2016-12-28 | 2017-05-31 | 利安隆（中卫）新材料有限公司 | The preparation method of chloride benzotriazole ultraviolet absorbent |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1455773A (en) * | 2001-01-15 | 2003-11-12 | Lg化学株式会社 | Method for preparing 2-(2-hydroxyphenyl)-2h-benzotriazole |
| CN103351349A (en) * | 2013-07-01 | 2013-10-16 | 天长市天佳化工科技有限公司 | Synthetic method for benzotriazole ultraviolet absorbent UV-P |
-
2016
- 2016-05-31 CN CN201610374220.XA patent/CN106008379A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1455773A (en) * | 2001-01-15 | 2003-11-12 | Lg化学株式会社 | Method for preparing 2-(2-hydroxyphenyl)-2h-benzotriazole |
| CN103351349A (en) * | 2013-07-01 | 2013-10-16 | 天长市天佳化工科技有限公司 | Synthetic method for benzotriazole ultraviolet absorbent UV-P |
Non-Patent Citations (2)
| Title |
|---|
| 朱宇翔等: "催化加氢合成苯并三氮唑类紫外吸收剂", 《高校化学工程学报》 * |
| 朱宇翔等: "催化加氢合成苯并三氮唑类紫外吸收剂", 《高校化学工程学报》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106749059A (en) * | 2016-12-28 | 2017-05-31 | 利安隆（中卫）新材料有限公司 | The preparation method of chloride benzotriazole ultraviolet absorbent |
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Application publication date: 20161012 |