CN103274974A - Method for synthesizing 2-nitro-4-methylsulfonylbenzoic acid - Google Patents
Method for synthesizing 2-nitro-4-methylsulfonylbenzoic acid Download PDFInfo
- Publication number
- CN103274974A CN103274974A CN2013102337208A CN201310233720A CN103274974A CN 103274974 A CN103274974 A CN 103274974A CN 2013102337208 A CN2013102337208 A CN 2013102337208A CN 201310233720 A CN201310233720 A CN 201310233720A CN 103274974 A CN103274974 A CN 103274974A
- Authority
- CN
- China
- Prior art keywords
- nitro
- follows
- hno
- reaction
- synthetic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 0 CS(c1ccc(C*)cc1)(=O)=O Chemical compound CS(c1ccc(C*)cc1)(=O)=O 0.000 description 2
- YYDNBUBMBZRNQQ-UHFFFAOYSA-N Cc(cc1)ccc1S(C)(=O)=O Chemical compound Cc(cc1)ccc1S(C)(=O)=O YYDNBUBMBZRNQQ-UHFFFAOYSA-N 0.000 description 2
- QNOUABMNRMROSL-UHFFFAOYSA-N CS(c(cc1)cc([N+]([O-])=O)c1C(O)=O)(=O)=O Chemical compound CS(c(cc1)cc([N+]([O-])=O)c1C(O)=O)(=O)=O QNOUABMNRMROSL-UHFFFAOYSA-N 0.000 description 1
Abstract
The invention provides a novel method for synthesizing 2-nitro-4-methylsulfonylbenzoic acid. Paratoluensulfonyl chloride is taken as a starting material, and the 2-nitro-4-methylsulfonylbenzoic acid is obtained at a high yield through the steps of methylation, halogenation, nitration and oxidation respectively. The synthesizing route is as follows: the method has the advantages that the problems of industrial three-waste pollution, high production cost, heavy metal pollution, complex operation and the like in a conventional process are solved; and the method has the characteristics of high yield and product purity, cleanness, safety, low production cost and capability of being popularized to large-scale industrial production, and has great importance in clean production.
Description
Technical field
The invention belongs to the organic synthesis field, specifically relate to the new synthetic method of a kind of 2-nitro-4-thiamphenicol benzoic acid.
Background technology
2-nitro-4-thiamphenicol benzoic acid is called for short NMSBA, is a kind of medicine that is widely used in, a kind of important intermediate of the important intermediate of agricultural chemicals, particularly synthesizing methyl sulphur humulone, and its structural formula is as follows:
Mesotrione (having another name called nitre sulphur humulone) is that Switzerland Syngenta Co.,Ltd is in the interior suction of the mid-1970s research and development in last century; selectivity; herbicide specially for corn field before the bud or behind the bud; it is with broad weed-killing spectrum; active high; miscibility is strong; toxicity is low; environmentally friendly; to succession crop safety; use characteristics such as flexible to obtain considerable success abroad; and domestic synthesis technique is still immature; mesotrione expired in August, 2012 in the administrative protection phase of China in addition, and the effect of preventing and kill off corn field weed that it is good and plentiful and substantial economic benefit attract the concern of the numerous manufacturing enterprises of China strongly.Therefore the synthesising process research of 2-nitro-4-thiamphenicol benzoic acid is with a wide range of applications.
At present both at home and abroad main adopt Tosyl chloride through methylate, the synthetic 2-nitro of denitrification step-4-methylsulfonyl toluene is as precursor, synthesizes 2-nitro-4-thiamphenicol benzoic acid by oxidizing reaction, be shown below:
This synthetic method extensively sees in the domestic and international patent, and still, there is more problem in this synthetic method for suitability for industrialized production.Such as: US Patent No. 5591890 introduce with the air oxidation process under the cobalt salt catalysis, but there is the pollution problem of metallic wastewater in this kind method, production efficiency is low simultaneously, and the yield about 70% is only arranged.US Patent No. 5424481 introduce with the nitric acid oxidation method of Vanadium Pentoxide in FLAKES as catalyzer, this method is that present industrial production is generally used, but there is serious nitrogen oxides pollution in this kind method, the waste acid liquor difficult treatment, the problems such as use of severe toxicity chemical Vanadium Pentoxide in FLAKES, cause the three industrial wastes amount big, problems such as operational hazards.World patent WO2004058698 has reported the method for oxidation that uses hydrogen peroxide, the consumption of this kind method hydrogen peroxide is nearly 30 times of material quantity, the sulfuric acid consumption will be nearly 20 times of material quantity, and this has just caused the problem that waste water is big, production efficiency is low, production cost is high.World patent WO2007099450 has reported at the metal vanadic salts, hydrogen peroxide under the catalysis of metallic cerium salt is as the method for oxidising agent, though effectively reduced the consumption of hydrogen peroxide, its yield also reduces greatly except the pollution problem of metal-salt waste water, only is about 40%.In addition, about synthesizing of 2-nitro-4-thiamphenicol benzoic acid, Chinese patent also has a large amount of reports, and such as the ozone-nitric acid oxidation method under the Vanadium Pentoxide in FLAKES catalysis of Chinese patent CN101177369 report, this kind method still can't be avoided the problems such as three-waste pollution of acid waste water and oxynitride.Chinese patent CN101503383 has introduced the use oleum and hydrogen peroxide is made persulfuric acid as oxidising agent, though improved the oxidation efficiency of hydrogen peroxide to a certain extent, but 70% sulfuric acid is applied mechanically the pollution problem that still has spent acid as solvent, the preparation of persulfuric acid has simultaneously increased the complicacy of its operation, production cost is big, and purity is low.The nitric acid oxidation method of Chinese patent CN101921215 report, the generation of a large amount of waste acid waters, potassium bichromate, the use of potassium permanganate etc., the pollution problem that brings is even more serious, and Chinese patent CN102584650 has introduced CuO/Al
2O
3The hydrogen peroxide oxidation method of carrier catalysis, wherein Preparation of catalysts has increased its production cost undoubtedly, and this kind method is outside the raw material that deduction reclaims, and yield can only accomplish that production efficiency is low about 79%.We find that all there are some problems in it to analyze the whole bag of tricks, such as: use nitric acid as oxidising agent, reaction is violent, easily produces side reaction, and has a large amount of oxynitrides to produce the severe contamination air; Use sulfuric acid as reaction medium, the generation of a large amount of acid waste waters, serious environment pollution; A large amount of uses of catalyzer easily cause again and pollute; The use of heavy metallic salt, the generation of heavy metal waste liquid, contaminate environment; Drawbacks such as complicated operation.Therefore, efficient, energy-conservation, environmental protection, the 2-nitro-4-thiamphenicol benzoic acid production technique of safety becomes the focus of Recent study.
Summary of the invention
The objective of the invention is to overcome the defective of prior art, by the redesign synthetic route, with 2-nitro 4-methylsulfonyl benzyl halide as reacting precursor, provide a kind of efficient, energy-conservation, environmental protection, safety is easy to realize the synthetic method that the 2-nitro-the 4-thiamphenicol benzoic acid is new of large-scale commercial production.Synthetic route is as follows:
The synthetic method of 2-nitro-4-thiamphenicol benzoic acid involved in the present invention is to be raw material with the Tosyl chloride, and process methylates, halo, and nitrated, oxidation step makes.Now will be summarized as follows step by step:
In the halo step, when X=Cl, chlorination reagent can be chosen as Cl
2, NCS (N-chlorosuccinimide), SO
2Cl
2Deng, solvent is tetracol phenixin, chlorobenzene, 1,2-dichlorobenzene etc.When X=Br, bromide reagent can be Br
2, NBS (N-bromo-succinimide), KBr/KBrO
3, NaBr/NaBrO
3, NaBrO
3/ NaHSO
3, HBr/H
2O
2, BBr
3Deng, solvent can be chosen as methylene dichloride, trichloromethane, ethyl acetate, acetone, ethanol, methyl alcohol, ether, acetonitrile, 1,4-dioxane etc.
Nitrating agent can be HNO in the denitrification step
3/ H
2SO
4, HNO
3/ acetic anhydride, HNO
3/ CH
2Cl
2, HNO
3/ 1,2-ethylene dichloride, NaNO
3/ H
2SO
4, KNO
3/ H
2SO
4, NO
xDeng.
Oxidising agent can use H in the oxidation step
2O
2, t-BuOOH, NaClO, NaBrO
3, KBrO
3, NaClO
3, KClO
3, potassium hydrogen persulfate composite salt, 2,2,6,6-tetramethyl piperidine-nitrogen-oxide compound (TEMPO), benzyl trimethyl tribromide ammonium (BTMA Br
3), O
2, O
3Deng.Reaction solvent is CH
3CN/H
2O, 1,4-dioxane/H
2O, acetone/H
2O, ethanol/H
2O, methyl alcohol/H
2O, aqueous sulfuric acid, aqueous hydrochloric acid, phosphate aqueous solution etc., temperature of reaction is 80 ℃～120 ℃.
Compare with the synthetic method of previous 2-nitro-4-thiamphenicol benzoic acid, the present invention is easy and simple to handle, product purity height, yield height.Especially the various three-waste pollution problems that exist in original technology have been significantly reduced.Significant for cleaner production.
Embodiment
In order further to set forth the present invention, be illustrated below in conjunction with embodiment.But be not limited thereto.
Embodiment 1
(1) intermediate a:4-methylsulfonyl toluene is synthetic
Take by weighing 10.08g NaHCO
3With 7.56g Na
2SO
3Input is equipped with in the 100ml four-hole bottle of thermometer, starts and stirs and heating, progressively is warming up to 75 ℃～80 ℃, and 9.53g (0.05mol) Tosyl chloride is joined in the four-hole bottle in batches, adds back insulated and stirred 2h.Add 8.76g ClCH
2COONa progressively is warming up to about 110 ℃, refluxes and stirs 18h.Question response is cooled to room temperature after fully, regulates pH value to neutral, filter crude product.Through water/ethyl alcohol recrystallization, the cooling, filter, wash intermediate a7.29g (theoretical yield 8.51g), yield 85.66%.
(2) intermediate b:4-methylsulfonyl bromo toluene is synthetic
Take by weighing step gained intermediate a1.70g (0.01mol), KBr1.55g, KBrO
30.43g in the input four-hole bottle, add 5ml trichloromethane and 5ml water, open and stir, wait to dissolve the back and drip the aqueous hydrochloric acid that 1.1ml concentrated hydrochloric acid and 5ml are made at 0 ℃, after dropwising, progressively be warming up to 20 ℃, after TLC follows the tracks of the reaction end, the separatory extraction, organic phase is through saturated NaSO
3Solution, the saturated common salt water washing is revolved the steaming precipitation and is got intermediate b crude product.Get intermediate b1.96g (theoretical yield 2.49g), yield 78.71% through sherwood oil/ethanol system recrystallization.
(3) intermediate c:2-nitro 4-methylsulfonyl bromo toluene is synthetic
Taking by weighing step gained intermediate b4.98g (0.02mol) drops in the four-hole bottle, the vitriol oil that adds 12.8ml98%, open to stir, progressively drip the mixed acid solution that the concentrated nitric acid by the vitriol oil of 6.2ml98% and 2.33g65% is made into, hierarchy of control temperature is between-15 ℃～0 ℃.TLC follows the tracks of reaction, after question response finishes, in the slow impouring 100ml of reaction system frozen water, has a large amount of solids to produce in the system, filters, respectively water and NaHCO
3The saturated solution washing leaching cake, dry intermediate c crude product.Get intermediate c5.31g (theoretical yield 5.88g), yield 90.31% through ethyl alcohol recrystallization.
(4) 2-nitro-4-thiamphenicol benzoic acid is synthetic
Take by weighing step gained intermediate c1.47g (0.005mol) and drop in the single port bottle, drop into 10mlCH in the reaction flask
3CN, 3.34gKBrO
3, reflux.TLC follows the tracks of reaction, after question response is complete, takes off dried solvent and namely gets 2-nitro-4-thiamphenicol benzoic acid crude product.Molten through alkali, acidifying gets 2-nitro-4-thiamphenicol benzoic acid 1.2g (theoretical yield 1.23g), yield 97.56%.
Embodiment 2
Synthesizing of intermediate b:4-methylsulfonyl bromo toluene
Take by weighing intermediate a4-methylsulfonyl toluene 8.51g (0.05mol), drop in the four-hole bottle, add the tetracol phenixin of 40ml drying as solvent, open and stir, be heated to reflux state, slowly drip the liquid Br of 8.79g drying
2, add 0.04gAlBN as the free radical reaction initiator, after TLC follows the tracks of the reaction end, the separatory extraction, organic phase is through saturated NaSO
3Solution, the saturated common salt water washing is revolved the steaming precipitation and is got intermediate b crude product.Get intermediate b9.95g (theoretical yield 12.46g), yield 79.86% through sherwood oil/ethanol system recrystallization.
Embodiment 3
Synthesizing of intermediate b:4-methylsulfonyl chlorotoluene
Take by weighing intermediate a4-methylsulfonyl toluene 8.51g (0.05mol), drop in the four-hole bottle, add the tetracol phenixin of 40ml drying as solvent, open and stir, be heated to reflux state, slowly feed dry chlorine, add 0.04g AlBN as the free radical reaction initiator, TLC follows the tracks of and reacts to the raw material disappearance, the separatory extraction, and organic phase is through saturated NaSO
3Solution, the saturated common salt water washing is revolved the steaming precipitation and is got intermediate b crude product.Get intermediate b8.65g (theoretical yield 10.23g), yield 84.56% through sherwood oil/ethanol system recrystallization.
Embodiment 4
Synthesizing of 2-nitro-4-thiamphenicol benzoic acid
Take by weighing intermediate c2-nitro 4-methylsulfonyl bromo toluene 5.88g (0.02mol), Na
2WO4H
2O0.1g drops in the four-hole bottle, adds 30ml CH
3CN is heated to backflow as solvent, slowly drips 30% hydrogen peroxide 13.6g, and about 8h dropwises, and TLC follows the tracks of reaction, and after question response was complete, rotary evaporation took off dried solvent and namely gets 2-nitro-4-thiamphenicol benzoic acid crude product.Molten through alkali, acidifying gets 2-nitro-4-thiamphenicol benzoic acid 4.7g (theoretical yield 4.9g), yield 95.92%.
Embodiment 5
Synthesizing of 2-nitro-4-thiamphenicol benzoic acid
Take by weighing intermediate c2-nitro 4-methylsulfonyl chlorotoluene 4.97g (0.02mol), drop in the four-hole bottle, add 20ml CH
3CN heats 40 ℃ as solvent, slowly drips 10%NaClO aqueous solution 59.55g, and about 8h dropwises, and after question response was finished, rotary evaporation took off dried solvent and namely gets 2-nitro-4-thiamphenicol benzoic acid crude product.Molten through alkali, acidifying gets 2-nitro-4-thiamphenicol benzoic acid 4.45g (theoretical yield 4.9g), yield 90.82%.
Embodiment 6
Take by weighing intermediate c2-nitro 4-methylsulfonyl chlorotoluene 4.97g (0.02mol), drop in the four-hole bottle, add 20mlCH
3CN is heated to reflux state as solvent, slowly drips 70%t-BuOOH aqueous solution 7.2g, and about 6h dropwises, and after question response was finished, rotary evaporation took off dried solvent and namely gets 2-nitro-4-thiamphenicol benzoic acid crude product.Molten through alkali, acidifying gets 2-nitro-4-thiamphenicol benzoic acid 4.65g (theoretical yield 4.9g), yield 94.88%.
Nuclear magnetic data:
Intermediate a4-methylsulfonyl toluene
1H?NMR(300MHz，CDCl
3)δ2.46(s，3H)，3.04(s，3H)，7.37(d，J＝8.0Hz，2H)，7.83(d，J＝8.2Hz，2H)。
Intermediate b4-methylsulfonyl bromo toluene
1H?NMR(300MHz，CDCl
3)δ3.07(s，3H)，4.52(s，2H)，7.60(d，J＝8.3Hz，1H)，7.93(d，J＝8.3Hz，1H)。
Intermediate c2-nitro 4-methylsulfonyl bromo toluene
1H?NMR(400MHz，DMSO)δ3.38(s，3H)，5.00(s，2H)，8.06(d，J＝8.1Hz，1H)，8.29(dd，J＝8.1，1.9Hz，1H)，8.54(d，J＝1.8Hz，1H)。
2-nitro-4-thiamphenicol benzoic acid
1H?NMR(400MHz，DMSO)δ3.40(s，3H)，8.11(d，J＝8.0Hz，1H)，8.33(d，J＝8.0Hz，1H)，8.52(s，1H)。
Claims (8)
1. the synthetic method of 2-nitro-4-thiamphenicol benzoic acid is characterized in that: be starting raw material by p-methyl benzene sulfonic chloride, and through the methylsulfonyl toluene of intermediate a, halo, nitrated, the synthetic 2-nitro of oxidation-4-thiamphenicol benzoic acid then.Its synthetic route is as follows:
2. synthetic method as claimed in claim 1, halo step feature is as follows:
It is characterized in that: when X=Cl, chlorination reagent can be Cl
2, NCS (N-chlorosuccinimide), SO
2Cl
2Deng; Solvent is tetracol phenixin, chlorobenzene, 1,2-dichlorobenzene etc.; Temperature of reaction is 80 ℃～180 ℃.
3. as right 1 and 2 described synthetic methods, it is characterized in that preferred chlorination reagent is Cl
2
4. synthetic method as claimed in claim 1, halo step feature is as follows:
It is characterized in that: when X=Br, bromide reagent can be Br
2, NBS (N-bromo-succinimide), KBr/KBrO
3, NaBr/NaBrO
3, NaBrO
3/ NaHSO
3, HBr/H
2O
2, BBr
3Deng; Solvent is methylene dichloride, trichloromethane, ethyl acetate, acetone, ethanol, methyl alcohol, ether, acetonitrile, 1,4-dioxane etc.; Temperature of reaction is-25 ℃～80 ℃.
5. as right 1 and 4 described synthetic methods, it is characterized in that preferred brominated reagent is KBr/KBrO
3, NaBr/NaBrO
3
6. synthetic method as claimed in claim 1, nitrated step feature is as follows:
It is characterized in that: nitrating agent can be HNO
3/ H
2SO
4, HNO
3/ acetic anhydride, HNO
3/ CH
2Cl
2, HNO
3/ 1,2-ethylene dichloride, NaNO
3/ H
2SO
4, KNO
3/ H
2SO
4, NO
xDeng.
7. as claim 1 and 6 described synthetic methods, it is characterized in that preferred nitrating agent is HNO
3/ H
2SO
4
8. synthetic method as claimed in claim 1, oxidation step feature is as follows:
It is characterized in that: oxidising agent can be H
2O
2, t-BuOOH, NaClO, NaBrO
3, KBrO
3, NaClO
3, KClO
3, potassium hydrogen persulfate composite salt, 2,2,6,6-tetramethyl piperidine-nitrogen-oxide compound (TEMPO), benzyl trimethyl tribromide ammonium (BTMA Br
3), O
2, O
3Deng.Reaction solvent is CH
3CN/H
2O, 1,4-dioxane/H
2O, acetone/H
2O, ethanol/H
2O, methyl alcohol/H
2O, aqueous sulfuric acid, aqueous hydrochloric acid, phosphate aqueous solution etc., temperature of reaction is 80 ℃～120 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013102337208A CN103274974A (en) | 2013-06-14 | 2013-06-14 | Method for synthesizing 2-nitro-4-methylsulfonylbenzoic acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013102337208A CN103274974A (en) | 2013-06-14 | 2013-06-14 | Method for synthesizing 2-nitro-4-methylsulfonylbenzoic acid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN103274974A true CN103274974A (en) | 2013-09-04 |
Family
ID=49057625
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2013102337208A Pending CN103274974A (en) | 2013-06-14 | 2013-06-14 | Method for synthesizing 2-nitro-4-methylsulfonylbenzoic acid |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103274974A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104262215A (en) * | 2014-09-22 | 2015-01-07 | 锦州凯创化工科技有限公司 | Preparation method of 2-nitro-4-methyl sulfone benzoic acid |
| CN109503437A (en) * | 2019-01-16 | 2019-03-22 | 江苏新鑫隆医药科技股份有限公司 | The preparation method of 2- nitryl-4-thiamphenicol benzoic acid |
| CN114195689A (en) * | 2021-11-29 | 2022-03-18 | 南京鹳山化工科技有限公司 | Novel synthesis process of 2-nitro-4-methylsulfonylbenzoic acid |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1296940A (en) * | 2000-11-24 | 2001-05-30 | 中国科学院上海有机化学研究所 | Environmentally friendly process for preparing benzoic acid and its derivatives |
| CN101628885A (en) * | 2009-08-21 | 2010-01-20 | 北京颖泰嘉和科技股份有限公司 | Preparation method of 2-nitryl-4-thiamphenicol benzoic acid |
-
2013
- 2013-06-14 CN CN2013102337208A patent/CN103274974A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1296940A (en) * | 2000-11-24 | 2001-05-30 | 中国科学院上海有机化学研究所 | Environmentally friendly process for preparing benzoic acid and its derivatives |
| CN101628885A (en) * | 2009-08-21 | 2010-01-20 | 北京颖泰嘉和科技股份有限公司 | Preparation method of 2-nitryl-4-thiamphenicol benzoic acid |
Non-Patent Citations (2)
| Title |
|---|
| GILBERT KIRSCH等: "New Thiophene Derivatives as Potential Materials for Non Linear Optics", 《J. HETEROCYCLIC CHEM.》 * |
| 来虎钦等: "2-硝基-4-甲磺酰基苯甲酸的绿色合成研究", 《浙江工业大学学报》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104262215A (en) * | 2014-09-22 | 2015-01-07 | 锦州凯创化工科技有限公司 | Preparation method of 2-nitro-4-methyl sulfone benzoic acid |
| CN109503437A (en) * | 2019-01-16 | 2019-03-22 | 江苏新鑫隆医药科技股份有限公司 | The preparation method of 2- nitryl-4-thiamphenicol benzoic acid |
| CN114195689A (en) * | 2021-11-29 | 2022-03-18 | 南京鹳山化工科技有限公司 | Novel synthesis process of 2-nitro-4-methylsulfonylbenzoic acid |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103601613B (en) | Preparation method of 3, 4, 5-trifluoro bromobenzene | |
| CN102516078B (en) | Preparation methods of glyoxylic acid L-menthyl alcohol ester and monohydrate of glyoxylic acid L-menthyl alcohol ester | |
| CN107573342B (en) | Preparation method of 1,1 '-ethylene-2, 2' -bipyridyl dichloride salt | |
| CN103772243A (en) | Preparation method of mesotrione | |
| CN105732444B (en) | A kind of his synthetic method of Baily department | |
| CN103274974A (en) | Method for synthesizing 2-nitro-4-methylsulfonylbenzoic acid | |
| CN108409616A (en) | A kind of preparation method of the halogenated -4- alkyl sulphonyls benzoic ethers of 3- bromomethyls -2- | |
| CN115368272A (en) | Preparation method of 4-cyano-2-methoxybenzaldehyde | |
| CN104059001B (en) | A kind of adjacent benzoic preparation method of nitro sulfuryl | |
| CN104672157A (en) | Method for preparing aryl triazolinone | |
| CN112110804B (en) | Preparation method of 3, 5-dihalo trifluoro acetophenone and its derivative | |
| CN103193611A (en) | Method for synthesizing m-trifluoromethyl acetophenone | |
| CN105294415A (en) | Preparation method of 3-halogenated fluorenone compound | |
| CN103819418B (en) | A kind of method synthesizing azoles oxadiazon and azoles oxadiazon intermediate | |
| ES2471365T3 (en) | A process for the ecological preparation of 3,5-dibromo-4-hydroxybenzonitrile | |
| CN103539728A (en) | Synthesis method of lansoprazole drug intermediate chloromethyl pyridine derivative | |
| CN103172549B (en) | Preparation method of 2-(2-nitryl-4-methyl sulfuryl-benzoyl) cyclohexane-1,3-diketone | |
| CN110615734B (en) | Industrialized synthesis method of o-aldehyde phenyl fatty acid | |
| CN105859559A (en) | Production method of 3-ethoxy-4-nitrophenol | |
| CN113149827A (en) | Method for synthesizing alkynoic acid by using terminal alkyne and carbon dioxide | |
| CN102633619A (en) | Preparation method of 6-halo-caproic acid | |
| CN112745216A (en) | Preparation method of methyl 4-bromomethylbenzoate and derivatives thereof | |
| CN109111370A (en) | A kind of preparation method of the bromo- 2- aminobenzoic acid of 3,5- bis- | |
| CN103450046B (en) | Method for preparing para hydroxybenzene acetonitrile | |
| CN101987814A (en) | Method for preparing 3,4,5-trimethoxyphenol |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20130904 |
|
| RJ01 | Rejection of invention patent application after publication |