CN104744217A - Hydroquinone synthesis method - Google Patents
Hydroquinone synthesis method Download PDFInfo
- Publication number
- CN104744217A CN104744217A CN201310739975.1A CN201310739975A CN104744217A CN 104744217 A CN104744217 A CN 104744217A CN 201310739975 A CN201310739975 A CN 201310739975A CN 104744217 A CN104744217 A CN 104744217A
- Authority
- CN
- China
- Prior art keywords
- reaction
- sulfuric acid
- nitrosyl
- acid
- resorcinol
- 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 **Cc(cc(cc1)O)c1[N+]=[O+] Chemical compound **Cc(cc(cc1)O)c1[N+]=[O+] 0.000 description 1
- PLIKAWJENQZMHA-UHFFFAOYSA-N Nc(cc1)ccc1O Chemical compound Nc(cc1)ccc1O PLIKAWJENQZMHA-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/01—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by replacing functional groups bound to a six-membered aromatic ring by hydroxy groups, e.g. by hydrolysis
- C07C37/04—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by replacing functional groups bound to a six-membered aromatic ring by hydroxy groups, e.g. by hydrolysis by substitution of SO3H groups or a derivative thereof
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention discloses a preparation method of hydroquinone (called as HQ for short). The preparation method comprises 1, diazotization reaction, 2, hydrolysis reaction, 3, extraction reaction and 4, purification reaction. Nitroso-sulfuric acid is used for the hydroquinone diazotization reaction so that the whole reaction system does not contain waste acid and through simple treatment, the hydrolyzed waste acid can be recycled and thus the preparation method is clean and environmentally friendly, does not produce a sodium salt in the reaction process and guarantees acid recycle.
Description
Technical field
The invention relates to the preparation method of Resorcinol (being called for short HQ).
Background technology
Resorcinol has another name called quinhydrones (HQ), it is a kind of important industrial chemicals, it is widely used, be important source material, intermediate and the auxiliary agent of medicine, agricultural chemicals, dyestuff and rubber etc., be mainly used in the aspects such as photographic developer, anthraquinone dye, azoic dyestuff, rubber antioxidant and monomer stopper, food stabiliser and coating antioxidant agent, anticoagulant.The Application Areas of current Resorcinol is expanded gradually, except except the application of traditional field, there has also been new development in fields such as chemical fertilizer, water treatment, liquid crystalline polymerss.Since nearest 10 years, the research of the aspects such as the production technique of researchist's many emphasis Resorcinol.
The method preparing HQ is more, general employing aniline oxidation style and hydoxylating phenol.In recent years, occurred taking p-aminophenol as the technique that Resorcinol prepared by raw material.
Be that to prepare Resorcinol be a variation route being different from aniline oxidation style, hydoxylating phenol to raw material with p-aminophenol, this route single stage method hydrolysis directly can prepare Resorcinol, also two steps can prepare Resorcinol.
In Japanese Patent Laid-Open No. Sho 53-2433, p-aminophenol and hydrogenchloride and hydrogen bromide is adopted to be hydrolyzed reaction according to mol ratio 1:2 respectively, hydrolysis temperature 230 DEG C, hydrolysis time 7 hours; When hydrogenchloride is hydrolyst, the transformation efficiency of p-aminophenol is 75.0%, and the selectivity of Resorcinol is 45.3%; When hydrogen bromide is hydrolyst, the transformation efficiency of p-aminophenol is 80.1%, and the selectivity of Resorcinol is 50.7%.In Japanese Patent Laid-Open No. Sho 53-12824, adopt respectively p-aminophenol and hydrogenchloride and hydrogen bromide in molar ratio 1:1 be hydrolyzed, hydrolysis temperature is 250 DEG C, hydrolysis time 6 hours; The yield of Resorcinol is respectively 90.1% and 93.7%.This technique weak point is: 1. have more tar to generate in reaction process; 2. severe reaction conditions: high temperature, strong acidic condition.
In US Patent No. 3862247, p-aminophenol prepares Resorcinol technique through high temperature, highly pressured hydrolysis.Detailed process: adopt p-aminophenol and monoammonium sulfate reactant aqueous solution, monoammonium sulfate and p-aminophenol mol ratio are 1.5-4, temperature of reaction 240-280 DEG C, reaction 2-6 hour, yield, at 58.4-72.7%, is up to 72.7%.There is subject matter in this technique: 1. the coal-tar middle oil amount of reaction process is large; 2. a large amount of sulfuric acid (hydrogen) ammonium black waste water is produced; 3. reaction yield about 70%, the refining rear total recovery only 55-60% that purifies; 4. severe reaction conditions: high temperature, high pressure, strongly-acid.
Patent CN200710163599.0 and CN201210249891.5, be all adopt p-aminophenol through diazotization and hydrolysis process synthesis Resorcinol, wherein CN201210249891.5 adopts copper sulfate hydrolysis method, and CN200710163599.0 adopts sulphuric acid hydrolysis.Copper sulfate hydrolysis method advantage is that temperature of reaction is low, and speed of response is fast, but can produce copper-containing wastewater, and spent acid treatment scheme is complicated; Sulphuric acid hydrolysis, adopts Sodium Nitrite and dilute sulphuric acid to carry out diazotization reaction, and the sulfuric acid with 30% is hydrolyzed reaction, advantage be flow process simply, two-step reaction total recovery can reach 90%, total recovery about 80%.But there is shortcoming in this technique: the sodium salt that doazo reaction generates enters enrichment in acid after hydrolysis reaction, reaction yield can be caused to decline when sodium salt in acid reaches certain content, what affect hydrolysis end acid applies mechanically stability, needs periodic exhaustion salty scrap acid, maintains applying mechanically of acid.
Summary of the invention
The object of the invention is: in order to improve the spatter property of diazonium hydrolysis process further, using nitrosyl-sulfuric acid to substitute Sodium Nitrite, provide a kind of p-aminophenol diazotization to be hydrolyzed the novel process preparing Resorcinol.
Reaction mechanism of the present invention is as follows:
The first step, synthesis nitrosyl-sulfuric acid:
Second step, p-aminophenol diazotization reaction:
3rd step, being hydrolyzed to react in sulphuric acid soln to diazo phenol vitriol generates Resorcinol:
The reaction formula that two steps merge is:
Preparation method and technical process:
(1) diazotization reaction: the p-aminophenol adding certain density sulfuric acid (being called diazotic acid), 98% content in doazo reaction device, stirring is cooled to-5 ~ 15 DEG C, then control temperature drips certain density nitrosyl-sulfuric acid solution to 0 ~ 5 DEG C, time for adding 1-1.5h, drip Bi Baowen 0.5h, the complete urea that adds of insulation stirs 15min, and insulation and charge temperature all remain on 0 ~ 5 DEG C, obtain as clear as crystal scarlet diazo liquid, preserve in 0 DEG C and treat that hydrolysis is used.
(2) hydrolysis reaction: add certain density sulfuric acid as end acid in hydrolysis reactor, be warming up to temperature of reaction, start low temperature and drip diazo liquid, time for adding is about 1-2hr, and drip Bi Baowen for some time, hydrolysis reaction terminates, and obtains hydrolyzed solution.
(3) extractive reaction; With extraction agent, hydrolyzed solution is extracted, be extracted oil reservoir and raffinate water layer.Extraction oil reservoir obtains Resorcinol finished product through precipitation, decoking, crystallization.Raffinate water layer 60-70wt% directly overlaps for hydrolysis reaction, and residue 30-40wt% is used for doazo reaction through removal of impurities process cover.
(4) removal of impurities reaction: for doazo reaction raffinate water layer through removal of impurities, concentrated after mix with nitrosonitric acid after as substrate, pass into sulfurous gas synthesis nitrosyl-sulfuric acid wherein, the raffinate water layer of remainder may be used for the neutralizing treatment of alkaline waste water.
In above-mentioned steps (1), sulphuric acid soln weight percent concentration is 9 ~ 30%, preferably 10 ~ 30%, best 15 ~ 20%; In p-aminophenol and aqueous sulfuric acid, vitriolated molar ratio is more than 1:2.0, preferred more than 1:2.2, best more than 1:2.4; The molar ratio of p-aminophenol and nitrosyl-sulfuric acid is 1:1 to 1:3, preferred 1:1 to 1:2, best 1:1.05 to 1:1.15.Temperature of reaction is-15 ~ 15 DEG C, preferably-10 ~ 5 DEG C, best-5 ~ 0 DEG C.
Described nitrosyl-sulfuric acid concentration at least 15%, preferred 20-50%, best 30-40%;
React complete, add urea, thiocarbamide, thioether etc. and destroy excessive nitrosyl-sulfuric acid.Above-mentioned admixture both can be used alone, also can two use together.Preferred urea and thiocarbamide, the amount added is advisable can destroy excessive nitrosyl-sulfuric acid completely.
In above-mentioned steps (2), hydrolysis end acid is certain density sulfuric acid, and sulfuric acid concentration is 20 ~ 50%, preferably 25 ~ 45%, best 30 ~ 40%; P-aminophenol amount is 1:6 to 1:20 with the mol ratio of hydrolysis sulfuric acid, preferred 1:10 to 1:18, best 1:12 to 1:16; Temperature of reaction is 105-115 DEG C, preferably 106 ~ 112 DEG C, best 108 ~ 110 DEG C.
In above-mentioned steps (3), hydrolysis reaction terminates, and reaction solution at room temperature extracts, and is extracted oil reservoir and raffinate water layer, and extraction oil reservoir obtains Resorcinol finished product through precipitation, decoking, crystallization.Raffinate aqueous fraction directly overlaps for hydrolysis reaction, and part is used for doazo reaction through removal of impurities process cover.
Reaction, extraction solvent for use can be ether, ester, ketone.Ethers is as ether, propyl ether, butyl ether; Ester class is as vinyl acetic monomer, propyl acetate, acetic acid (just) butyl ester, tributyl phosphate, trioctyl phosphate etc.; Ketone is as methyl ethyl ketone, methyl iso-butyl ketone (MIBK), methyl tertbutyl ketone etc.; Preferred n-butyl acetate, methyl iso-butyl ketone (MIBK) etc.
Described extraction oil reservoir is mainly containing the tar that Resorcinol, extraction agent and a small amount of reaction generate.The main sulfur acid of described raffinate water layer, water, microextraction agent and Trace Hydroquinone.
Reaction raffinate water layer is used for doazo reaction through removal of impurities process cover, described removal of impurities treatment process can be activated carbon decolorizing process, diatomite adsorption process, hydrogen peroxide oxidation process, ozone Oxidation Treatment etc., wherein activated carbon decolorizing process, activated carbon dosage is 0.02-2%, preferred 0.05-1.5%, best 0.08-1.0%.Diatomite adsorption process, diatomite consumption is 1-10%, preferred 3-8%, best 4-6%.Hydrogen peroxide oxidation process, the concentration of hydrogen peroxide is 20-50%, preferred 25-40%, best 30-40%.The consumption of hydrogen peroxide is 0.5-6%, preferred 1-5%, best 2-3%.
In above-mentioned steps (4), react raffinate water layer after removal of impurities process for the synthesis of nitrosyl-sulfuric acid.
The maximum advantage of the present invention be exactly whole reaction system without salty scrap acid, hydrolysis spent acid can be applied mechanically through simple process, technique clean environment firendly.It is the fact known that nitrosyl-sulfuric acid is used for diazotization reaction, but not representing what reaction can substitute Sodium Nitrite with nitrosyl-sulfuric acid.Sodium Nitrite is conventional diazo reagent, and raw material is easy to get, and reaction is simple, and the general Sodium Nitrite that adopts is difficult to the amine carrying out diazotization reaction, just can consider to select nitrosyl-sulfuric acid.Find in experimentation, adopt Sodium Nitrite to carry out diazotization reaction and can generate sodium pyrosulfate, sodium pyrosulfate is enriched to a certain amount of meeting and has an impact to reaction in acid, need regular discharge part salty scrap acid, so from environmental angle, start the substitute considering to find Sodium Nitrite, eventually pass through screening and have selected nitrosyl-sulfuric acid, its maximum advantage is exactly that reaction process can not generate sodium salt, can ensure that the stable circulation of acid is applied mechanically.
Really diazotization reaction can be carried out from both reaction effects, but nitrosyl-sulfuric acid more lays particular emphasis in the recycled stability of acid and the feature of environmental protection of technique.
Embodiment
Embodiment 1(reactive moieties)
Resorcinol preparation method carries out according to the following steps:
Diazotization reaction: add 15% sulfuric acid 245g, industrial goods 98% p-aminophenol 27.8g in 1000mL reactor, stirring is cooled to-5 ~ 0 DEG C, drip 40% nitrosyl-sulfuric acid solution 87.3g, time for adding 1-1.5hr, drip Bi Baowen 0.5hr, add 1.5g urea, stir 15min, when nitrogen is released not obvious, add 1.5g thiocarbamide and stir 15min again.Dropping, insulation and charge temperature all remain on-5 ~ 5 DEG C, obtain diazo liquid 350-360g, in 0 DEG C of preservation.
Hydrolysis reaction: first add 40% sulfuric acid 1000g in 2000mL reactor, be heated to 106-110 DEG C, above-mentioned diazo liquid, in about 0 DEG C dropping, drips 1-1.5hr, in 106-110 DEG C of insulation 3-4hr, obtains hydrolyzed solution and is about 1350g.
Extraction: hydrolyzed solution is down to room temperature, and reaction solution methyl iso-butyl ketone (MIBK) 300g divides three extractions, extraction oil reservoir is about about 320-330g, and containing Resorcinol about 7.6%, oil reservoir obtains Resorcinol crystal be about 22.1g through precipitation, decoking, crystallization; Raffinate water layer 1300g, containing Resorcinol less than 0.05%, acid concentration about 40%, hydrolysis reaction yield 91-92%.
Embodiment 2-6
Preparation method is with embodiment 1, and difference is: change doazo reaction sulfuric acid concentration.
Embodiment 7-12
Preparation method is with embodiment 1, and difference is: the temperature changing doazo reaction.
Embodiment 13-17
Preparation method is with embodiment 1, and difference is: the content changing nitrosyl-sulfuric acid in doazo reaction.
Embodiment 18-23
Preparation method is with embodiment 1, and difference is: the concentration changing hydrolysis sulfuric acid.
Embodiment 24(spent acid aftertreatment)
Hydrolysis spent acid aftertreatment: raffinate water layer taking-up 1000g is directly overlapped and is used for being hydrolyzed end acid.Take out about 92g add 0.1g gac carry out desolventing technology (90 DEG C, 2hr) overlap afterwards be used for doazo reaction.
The synthesis of nitrosyl-sulfuric acid: taking-up 130g adds 1.5g35% hydrogen peroxide and carries out oxide treatment, again acidity is concentrated into about 80%, the nitrosonitric acid of 20g97% is added in sulfuric acid after concentrated, sulfur dioxide gas is passed into wherein after mixing, ventilation flow rate is about 2-3L/hr, time is about the nitrosyl-sulfuric acid that 2-3hr can synthesize 40%, for doazo reaction.The spent acid of remaining about 78g40% may be used for the neutralization of alkaline waste water.
Embodiment 25-27
Preparation method is with embodiment 1, and spent acid post-treating method is with embodiment 24, and difference is: the spent acid removal of impurities mode of synthesis nitrosyl-sulfuric acid is different.
Embodiment 28-29
Preparation method is with embodiment 1, and spent acid post-treating method is with embodiment 24, and difference is: adopt the content of spent acid synthesis nitrosyl-sulfuric acid different.
Embodiment 30-40
Preparation method is with embodiment 1, and spent acid post-treating method is with embodiment 24, and difference is: the impact of applying mechanically yield investigating hydrolysis sulfuric acid.
Claims (10)
1. a synthetic method for Resorcinol, is characterized in that, comprises the following steps:
(1) diazotization reaction: the p-aminophenol adding sulfuric acid, 98% content in doazo reaction device, stirring is cooled to-5 ~ 15 DEG C, then control temperature drips nitrosyl-sulfuric acid solution at 0 ~ 5 DEG C, time for adding 1 ~ 1.5h, drip Bi Baowen 0.5h, the complete urea that adds of insulation stirs 15min, and insulation and charge temperature all remain on 0 ~ 5 DEG C, obtain as clear as crystal scarlet diazo liquid, preserve in 0 DEG C and treat that hydrolysis is used;
(2) hydrolysis reaction: add sulfuric acid as end acid in hydrolysis reactor, be warming up to temperature of reaction, start to drip diazo liquid, time for adding is 1 ~ 2h about, and drip Bi Baowen for some time, hydrolysis reaction terminates, and obtains hydrolyzed solution.
(3) extractive reaction: hydrolyzed solution is at room temperature extracted with extraction agent, extraction is extracted oil reservoir and raffinate water layer, extraction oil reservoir obtains Resorcinol finished product through precipitation, decoking, crystallization, raffinate water layer 60-70wt% directly overlaps for hydrolysis reaction, and residue 30-40wt% is used for doazo reaction through removal of impurities process cover.
(4) removal of impurities reaction: for doazo reaction raffinate water layer through removal of impurities, concentrated after mix with nitrosonitric acid after as substrate, pass into sulfurous gas synthesis nitrosyl-sulfuric acid wherein, the raffinate water layer of remainder may be used for the neutralizing treatment of alkaline waste water.
2. the synthetic method of Resorcinol according to claim 1, it is characterized in that, in described step (1), sulphuric acid soln weight percent concentration is 9 ~ 30%, in p-aminophenol and aqueous sulfuric acid, vitriolated molar ratio is more than 1:2.0, the molar ratio of p-aminophenol and nitrosyl-sulfuric acid is 1:1 to 1:3, described nitrosyl-sulfuric acid concentration at least 15%, temperature of reaction is-15 ~ 15 DEG C.
3. the synthetic method of Resorcinol according to claim 1, it is characterized in that, in described step (1), sulphuric acid soln weight percent concentration is 10 ~ 30%, in p-aminophenol and aqueous sulfuric acid, vitriolated molar ratio is more than 1:2.2, the molar ratio of p-aminophenol and nitrosyl-sulfuric acid is 1:1 to 1:2, described nitrosyl-sulfuric acid concentration 20-50%, temperature of reaction is-10 ~ 5 DEG C.
4. the synthetic method of Resorcinol according to claim 1, it is characterized in that, in described step (1), sulphuric acid soln weight percent concentration is 15 ~ 20%, in p-aminophenol and aqueous sulfuric acid, vitriolated molar ratio is more than 1:2.4, the molar ratio of p-aminophenol and nitrosyl-sulfuric acid is 1:1.05 to 1:1.15, described nitrosyl-sulfuric acid concentration 30 ~ 40%, temperature of reaction is-5 ~ 0 DEG C.
5. the synthetic method of Resorcinol according to claim 1, is characterized in that, in above-mentioned steps (2), hydrolysis end acid is certain density sulfuric acid, and sulfuric acid concentration is 20 ~ 50%, preferably 25 ~ 45%, best 30 ~ 40%; P-aminophenol amount is 1:6 to 1:20 with the mol ratio of hydrolysis sulfuric acid, preferred 1:10 to 1:18, best 1:12 to 1:16; Temperature of reaction is 105 ~ 115 DEG C, preferably 106 ~ 112 DEG C, best 108 ~ 110 DEG C.
6. the synthetic method of Resorcinol according to claim 1, is characterized in that, reaction, extraction solvent for use can be ether, ester, ketone, and ethers is: ether, propyl ether, butyl ether; Ester class is: vinyl acetic monomer, propyl acetate, acetic acid (just) butyl ester, tributyl phosphate, trioctyl phosphate etc.; Ketone is: methyl ethyl ketone, methyl iso-butyl ketone (MIBK), methyl tertbutyl ketone etc.
7. the synthetic method of Resorcinol according to claim 1, is characterized in that, the tar that described extraction oil reservoir generates containing Resorcinol, extraction agent and a small amount of reaction, described raffinate water layer sulfur acid, water, microextraction agent and Trace Hydroquinone.
8. the synthetic method of Resorcinol according to claim 1, it is characterized in that, raffinate water layer is used for doazo reaction through removal of impurities process cover, described removal of impurities treatment process can be activated carbon decolorizing process, diatomite adsorption process, hydrogen peroxide oxidation process, ozone Oxidation Treatment etc., wherein activated carbon decolorizing process, activated carbon dosage is 0.02 ~ 2%, preferably 0.051 ~ .5%, best 0.08 ~ 1.0%, diatomite adsorption process, diatomite consumption is 1 ~ 10%, preferably 3 ~ 8%, best 4 ~ 6%, hydrogen peroxide oxidation process, the concentration of hydrogen peroxide is 20 ~ 50%, preferably 25 ~ 40%, best 30 ~ 40%, the consumption of hydrogen peroxide is 0.5 ~ 6%, preferably 1 ~ 5%, best 2 ~ 3%.
9. the synthetic method of Resorcinol according to claim 1, is characterized in that, in above-mentioned steps (4), raffinate water layer after removal of impurities process for the synthesis of nitrosyl-sulfuric acid.
10. the synthetic method of Resorcinol according to claim 1, it is characterized in that, react complete, add urea, thiocarbamide, thioether destroy excessive nitrosyl-sulfuric acid, above-mentioned admixture both can be used alone, also can two use together, the amount added is advisable can destroy excessive nitrosyl-sulfuric acid completely.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310739975.1A CN104744217A (en) | 2013-12-27 | 2013-12-27 | Hydroquinone synthesis method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310739975.1A CN104744217A (en) | 2013-12-27 | 2013-12-27 | Hydroquinone synthesis method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104744217A true CN104744217A (en) | 2015-07-01 |
Family
ID=53584578
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310739975.1A Pending CN104744217A (en) | 2013-12-27 | 2013-12-27 | Hydroquinone synthesis method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104744217A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105418453A (en) * | 2015-12-01 | 2016-03-23 | 浙江闰土研究院有限公司 | Process for diazotizing azo-dye intermediate |
| CN109456150A (en) * | 2018-10-25 | 2019-03-12 | 浙江林江化工股份有限公司 | A kind of synthetic method of 3,4,5-Trifluoro phenol |
| CN114591146A (en) * | 2020-12-03 | 2022-06-07 | 中国科学院大连化学物理研究所 | Method for preparing hydroquinone from p-aminophenol |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4009212A (en) * | 1973-02-21 | 1977-02-22 | Koppers Company, Inc. | Method for the preparation of meta dihydroxybenzenes |
| CN101412662A (en) * | 2007-10-16 | 2009-04-22 | 江苏扬农化工集团有限公司 | Method for preparing p-dihydroxy benzene |
| CN102964221A (en) * | 2012-11-26 | 2013-03-13 | 江苏扬农化工股份有限公司 | Clean production process of dicamba synthesis midbody |
-
2013
- 2013-12-27 CN CN201310739975.1A patent/CN104744217A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4009212A (en) * | 1973-02-21 | 1977-02-22 | Koppers Company, Inc. | Method for the preparation of meta dihydroxybenzenes |
| CN101412662A (en) * | 2007-10-16 | 2009-04-22 | 江苏扬农化工集团有限公司 | Method for preparing p-dihydroxy benzene |
| CN102964221A (en) * | 2012-11-26 | 2013-03-13 | 江苏扬农化工股份有限公司 | Clean production process of dicamba synthesis midbody |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105418453A (en) * | 2015-12-01 | 2016-03-23 | 浙江闰土研究院有限公司 | Process for diazotizing azo-dye intermediate |
| CN109456150A (en) * | 2018-10-25 | 2019-03-12 | 浙江林江化工股份有限公司 | A kind of synthetic method of 3,4,5-Trifluoro phenol |
| CN114591146A (en) * | 2020-12-03 | 2022-06-07 | 中国科学院大连化学物理研究所 | Method for preparing hydroquinone from p-aminophenol |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103922416B (en) | A kind of method of Separation and Recovery iron from red mud | |
| EP2754652A1 (en) | Taurine preparation method | |
| CN103539700B (en) | Preparation method of N-cyanoethylaniline | |
| CN104557639A (en) | Method of preparing 2-nitro-4-methylsulfonyl benzoic acid | |
| CN108640156A (en) | A method of preparing tungsten oxide and tungsten powder from scheelite | |
| CN104744217A (en) | Hydroquinone synthesis method | |
| CN106966882A (en) | A kind of preparation method of tetrachloroquinone | |
| CN103539704A (en) | Method for preparing diuron | |
| CN103193611B (en) | A kind of synthetic method of (TrifluoroMethyl)acetophenone | |
| CN106278875A (en) | A kind of production method of isooctyl acid | |
| CN108677037A (en) | A kind of method that acid decomposes wolframite extraction tungsten | |
| CN106431887A (en) | Method for preparing trimesic acid | |
| CN104368340B (en) | A kind of preparation of sponge silver catalyst and the application in cinnamic acid oxidation synthesizing cinnamic acid thereof | |
| CN1948236A (en) | Method of producing potassium ammonium sulfate compound fertilizer using potassium containing rock | |
| CN105036158B (en) | Method for preparing sodium nitrate through solvent extraction | |
| CN105198726A (en) | Preparation method of organic bismuth subgallate | |
| CN101402552B (en) | Method for producing m-cresol with direct hydrolyzation | |
| CN105669357B (en) | A kind of green preparation process of 1,4- diiodo-benzenes | |
| CN108559841A (en) | A kind of method that acid decomposition Scheelite-Wolframite Mixed Mine prepares tungsten product | |
| CN102276423A (en) | Method for producing hydroquinone by direct hydrolysis of p-phenylenediamine | |
| CN102311420A (en) | Method for synthesizing epsilon-caprolactone | |
| CN107162894A (en) | The post-treatment new process of the chlorobenzoic acid of 5 bromine 2 | |
| CN111559959A (en) | Synthetic method of p-trifluoromethylphenol | |
| CN106866432A (en) | A kind of synthesis technique of nitrophenol and its intermediate | |
| CN102229549B (en) | Method for preparing isooctyl mercaptoacetate |
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: 20150701 |
|
| RJ01 | Rejection of invention patent application after publication |