CN101857550A - Method for producing 6-aminocaproic acid hydrochloride and 6-aminocaproic acid by using nylon-6 waste through depolymerization - Google Patents
Method for producing 6-aminocaproic acid hydrochloride and 6-aminocaproic acid by using nylon-6 waste through depolymerization Download PDFInfo
- Publication number
- CN101857550A CN101857550A CN200910097550A CN200910097550A CN101857550A CN 101857550 A CN101857550 A CN 101857550A CN 200910097550 A CN200910097550 A CN 200910097550A CN 200910097550 A CN200910097550 A CN 200910097550A CN 101857550 A CN101857550 A CN 101857550A
- Authority
- CN
- China
- Prior art keywords
- aminocaprolc acid
- nylon
- acid hydrochloride
- waste
- solution
- 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.)
- Granted
Links
Images
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention discloses a method for producing 6-aminocaproic acid hydrochloride and 6-aminocaproic acid by using nylon-6 waste through depolymerization. The method is characterized by comprising the following steps of: depolymerizing the nylon-6 waste at the temperature of between 100 and 110 DEG C under constant pressure by using 10 to 20 percent solution of hydrochloric acid so as to obtain acidolysis solution, and filtering, separating, purifying, and drying to obtain refined 6-aminocaproic acid hydrochloride; and introducing ammonia into the solution of 6-aminocaproic acid hydrochloride to neutralize the solution to the pH of between 3 and 9, adding industrial alcohol in a volume 3 to 5 times that of the solution, and recrystallizing to obtain the refined 6-aminocaproic acid. The method has the advantages of simple technical process, low production cost, a few by-products, high yield of the aminocaproic acid, and safe production process.
Description
Technical field
The present invention relates to a kind of suitability for industrialized production that is suitable for comes depolymerization nylon-6 waste to produce the method for 6-aminocaprolc acid hydrochloride and 6-aminocaprolc acid with acid.
Background technology
6-aminocaprolc acid is called for short 6-ACA, generally adopts after direct chemical synthesis method, hexanolactam or caprolactam polymerization thing (frit of nylon-6, waste silk, discarded fabric, the fishing net etc.) hydrolysis refining and make.6-aminocaprolc acid (6-ACA) is used for synthesis of caprolactam, and subsequently to the production of nylon-6,6-ACA can also directly be used as the starting material of producing nylon-6.In addition, 6-aminocaprolc acid the purposes of wide model be to be applied in the medical field to have positive effect to increase some severe haemorrhage that causes because of the cellulose protein hemolytic activity as hemostatic agent.Acute illnesss such as oozing of blood when being applicable to multiple surgical operation or local hemorrhage, Obstetric and Gynecologic Department are hemorrhage, digestive tract hemorrhage.
At present, produce the method for preparing 6-aminocaprolc acid and have following two kinds substantially:
One, with the hexanolactam be starting material, make the 6-aminocaprolc acid hydrochloride through hydrochloric acid hydrolysis, then, with its dilution, by storng-acid cation exchange resin absorption, again through purifying, the refining 6-aminocaprolc acid that obtains.This method length consuming time, schedule of operation is loaded down with trivial details, and production cost increases.Another kind method is that the 6-aminocaprolc acid hydrochloride solid that obtains is water-soluble, handles with the aluminium hydroxide and the oxidation silver powder of yellow lead powder, new system successively, removes halogen ion and metal ion with hydrogen sulfide treatment again, obtains 6-aminocaprolc acid through crystallization, drying.This method obviously increases production cost, and operation is more loaded down with trivial details, and uses toxic hydrogen sulfide, the dangerous increase.Patent CN101125821A has invented a kind of method for preparing the hemostatic agent 6-aminocaprolc acid.With the hexanolactam is starting material, makes the 6-aminocaprolc acid hydrochloride through hydrochloric acid hydrolysis, utilizes spherical polystyrene weak base anion-exchange resin to neutralize, and obtains 6-aminocaprolc acid through aftertreatment.This invention condition is relatively gentleer, is difficult for the tramp m. ion, and is simple to operate, reduces production costs, and still, its shortcoming is exactly consuming time longer, and efficient is low.
Two, prepare 6-aminocaprolc acid by the organic chemistry synthetic method.For example, U.S. E.I. Du Pont De Nemours ﹠ Co. is the patent at China's application preparation 6-aminocaprolc acid in calendar year 2001, publication number is CN1505606A, this invention generates 3-, 4-and 5-formylvaleronitriles (FVN mixture) by the 3 pentene nitrile hydroformylation, the FVN mixture generates 3-, 4-and 5-cyanopentanoic acid through oxidation, obtains 6-aminocaprolc acid through over hydrogenation again; Holland DSM N. V. has applied for a kind of patent for preparing ε-Ji Neixianan, 6-aminocaprolc acid and 6-aminocaproamide mixture in China, and publication number is CN1216529A; Holland DSM IP Assets BV disclosed the patent that a kind of biological chemistry synthetic method prepares 6-aminocaprolc acid in 2007, this invention is by with having α, the enzyme of β-olefin(e) acid ester reductase activity removes to handle α, and β-olefin(e) acid ester group and primary amine groups molecule are realized.Above-mentionedly prepare the shortcoming that 6-aminocaprolc acid exists by the organic chemistry synthetic method and mainly contain: a large amount of chemical reaction step of needs is finished, the material cost height of reaction usefulness, dangerous big, the by product that the target product that generates produces is many, difficulty is separated, yield is low, is not suitable for suitability for industrialized production.
At the above-mentioned existing shortcoming of method for preparing 6-aminocaprolc acid, the present invention adopts hydrochloric acid to come depolymerization nylon-6 waste to produce 6-aminocaprolc acid hydrochloride and 6-aminocaprolc acid.The nylon-6 waste is dropped into the hydrochloric acid soln depolymerization obtain thick 6-aminocaprolc acid hydrochloride solution, obtain refining 6-aminocaprolc acid hydrochloride through purifying, then, it is concentrated, feed ammonia solution is neutralized to pH3-9, add the industrial alcohol of 3-5 times of volume, separate out crystal, the refining 6-aminocaprolc acid that obtains.This is invented, and compared with prior art technological process is simple, does not adopt Zeo-karb to separate, and saves the production time, enhances productivity; The preparation condition gentleness does not need complicated chemical reaction step and harsh test conditions, reduces production costs; The 6-aminocaprolc acid purity height, the productive rate that make are big; With discarded nylon-6 is that material cost is low, has solved the recycling problem of nylon 6 wastes simultaneously.This method is science, reasonable more, meets the current environmental protection theory of advocating, and is suitable for the commercial scale production 6-aminocaprolc acid.
Summary of the invention
The technical problem to be solved in the present invention is: at the recycling problem of nylon-6 waste, and the existing preparation procedure of current preparation 6-aminocaprolc acid is more loaded down with trivial details, production cost is higher, product yield is lower, by product is more, difficult isolating problem, a kind of method of producing 6-aminocaprolc acid hydrochloride and 6-aminocaprolc acid with the nylon-6 waste through depolymerization is provided, its technological process is simple, do not adopt Zeo-karb to separate, save the production time, enhance productivity; The preparation condition gentleness does not need complicated chemical reaction step and harsh test conditions, reduces production costs, and the 6-aminocaprolc acid purity height, the productive rate that make are big.
The present invention solves the technical scheme that its technical problem takes: a kind of method of producing 6-aminocaprolc acid hydrochloride and 6-aminocaprolc acid with the nylon-6 waste through depolymerization, it is characterized in that including acidolysis workshop section, the separation of 6-aminocaprolc acid hydrochloride and purifying workshop section, 6-aminocaprolc acid and prepare workshop section, each workshop section's step is as described below:
(1), acidolysis workshop section, mass concentration 10-20% aqueous hydrochloric acid is added the top to be had in the enamel reaction still of condensation reflux unit and hydrogen chloride gas absorption unit, mass ratio 100 according to nylon-6 and hydrogenchloride: 25-35 adds nylon-6, under the condition of normal pressure and 100-110 ℃, reacted 6～12 hours, obtain acid hydrolysis solution;
(2), the 6-aminocaprolc acid hydrochloride separates and purifying workshop section, and reactor is slowly vacuumized, and treats that absolute pressure kept later on 20-30 minute less than 10KPa, the acid hydrolysis solution in the step (1) is cooled to 30-40 ℃, uses activated carbon decolorizing behind the filtration residue; The thick 6-aminocaprolc acid hydrochloride solution that obtains, reduction vaporization is concentrated into the 30-40% of cumulative volume, is cooled to 30-45 ℃, filters the thick 6-aminocaprolc acid hydrochloride of separating out, and obtains refining 6-aminocaprolc acid hydrochloride with industrial ethyl alcohol recrystallization, drying;
(3), 6-aminocaprolc acid prepares workshop section, feed ammonia in the thick 6-aminocaprolc acid hydrochloride solution after in step (2), concentrating solution is neutralized to pH3-9, the industrial alcohol that adds 3-5 times of volume, fully stirring and low-grade fever are after 50-70 ℃, naturally cool to room temperature, the 6-aminocaprolc acid that filtration is separated out must be made with extra care 6-aminocaprolc acid after the washing with alcohol drying.
The described reaction times is dependent on the property of raw material of nylon-6 waste, when common nylon-6 carpet wool is done raw material, and preferred 8 hours.
Gac is adopted in decolouring described in the step (2), and add-on is the 2-5% of thick 6-aminocaprolc acid hydrochloride solution total mass.
Vaporized distillate fluid described in vacuum Extract described in hydrogen chloride gas absorption liquid described in the step (1), the step (2), the step (2) and filtrate merge, and reuse is to step (1) after the mensuration acidity.
Be neutralized to the process of pH value of solution 3-9 with ammonia described in the step (3), add strong aqua (22-25% if adopt, mass concentration, the industry first grade) is neutralized to pH value of solution 3-9, then, add the industrial alcohol of 1-3 times of volume while hot, filter the crystallization of separating out the extremely near state of doing of solution evaporation, use the washing with alcohol drying, must make with extra care 6-aminocaprolc acid.
The used ethanol of recrystallization described in the step (2), or after used ethanol merges in used ethanol or the strong aqua N-process in the step (3), through rectifying tower distillation back reuse.
Produce in the method for 6-aminocaprolc acid, then in ethanol distillation is recycled, the ethanol distillation raffinate till needs continuation this moment evaporation concentration to ammonium chloride begins to separate out, gets by-product ammonium chloride because of containing the not directly waste treatment of a large amount of ammonium chlorides behind the naturally cooling filtration drying.
The present invention compared with prior art has the following advantages and benefit:
1, come depolymerization to discard nylon-6 with the 10-20% aqueous hydrochloric acid, the temperature of hydrolysis is lower and can carry out under normal pressure, makes things convenient for suitability for industrialized production, and transformation efficiency is than higher; And filtrate that obtains after depolymerization is finished and vaporized distillate fluid merge, and can be recycled after the mensuration acidity;
2, with in the ammonia and 6-aminocaprolc acid hydrochloride solution to pH3-9, add the industrial alcohol recrystallization again, the refining 6-aminocaprolc acid that obtains.Or adopt the adding strong aqua to be neutralized to pH value of solution 3-9, and solution evaporation to the nearly state of doing, is added the industrial alcohol of 1-3 times of volume while hot, filter the crystallization of separating out, use the washing with alcohol drying, must make with extra care 6-aminocaprolc acid.It is longer so just to have avoided employing ion exchange resin to carry out the separation consumes time, and the shortcoming that schedule of operation is many is enhanced productivity;
3, with the nylon-6 waste as starting material, reduced production cost, solved the recycling problem of nylon 6 wastes, the theory that meets recycling economy and Sustainable development, and production process safety, pollution-free substantially to environment, the by product that produces in the production process is less, be convenient to separation and purification, improved 6-aminocaprolc acid purity.
Description of drawings
Fig. 1 process flow diagram;
Fig. 2 reaction process synoptic diagram.
Embodiment
Embodiment describes in further detail the present invention below in conjunction with accompanying drawing.
Embodiment 1
(1) has the 30% industrial by-product hydrochloric acid that adds 1000Kg in the enamel reaction still of condensation reflux unit and hydrogen chloride gas absorption unit at the top, add 750Kg water again, the limit heating edge adds 1000Kg waste material nylon-6, and reaction is 10 hours under the condition of normal pressure and 100-110 ℃, obtains acid hydrolysis solution;
(2) reactor is evacuated to absolute pressure and kept later on 30 minutes, acid hydrolysis solution is cooled to 35 ℃, remove by filter residue, then, add the 80Kg gac and decolour, obtain thick 6-aminocaprolc acid hydrochloride solution less than 10KPa;
The thick 6-aminocaprolc acid hydrochloride solution decompression evaporation concentration that (3) will obtain is to the 30-40% of cumulative volume, be cooled to 30-45 ℃, the thick 6-aminocaprolc acid hydrochloride that filtration is separated out obtains refining 6-aminocaprolc acid hydrochloride with industrial alcohol recrystallization, the drying of 2 times of volumes;
(4) feeding ammonia in the thick 6-aminocaprolc acid hydrochloride solution that obtains in (2) step is neutralized to solution about pH=7, the industrial alcohol that adds 3-5 times of volume, after fully stirring and being heated to 60 ℃, naturally cool to room temperature, the 6-aminocaprolc acid that filtration is separated out, obtain refining 6-aminocaprolc acid white powder with the absolute ethanol washing drying, yield is greater than 90%, purity 98%.
Embodiment 2
Step (1) (2) is with embodiment 1.
(3) adding commercially available strong aqua in the thick 6-aminocaprolc acid hydrochloride solution that obtains in (2) step is neutralized to solution about pH=7, reduction vaporization is concentrated into 20% of neutralization back overall solution volume, the industrial alcohol that adds 4 times of residual volumes while hot, after fully stirring, naturally cool to room temperature, filter the 6-aminocaprolc acid of separating out, obtain refining 6-aminocaprolc acid white powder with the absolute ethanol washing drying, yield is greater than 90%, purity 98%.
(4) ethanol filtrate in the step (3) and washing step exhausted ethanol are merged, rectifying in rectifying tower, the cut of collecting 75-80 ℃ obtains 95% aqueous ethanolic solution, recycles.Continue to distill out portion water to bottom product and begin to occur crystallization and stop, bottom product is expelled to cooling tank, natural cooling crystallization, filtration drying gets the by-product ammonium chloride white powder.
Claims (7)
1. method of producing 6-aminocaprolc acid hydrochloride and 6-aminocaprolc acid with the nylon-6 waste through depolymerization, it is characterized in that including acidolysis workshop section, the separation of 6-aminocaprolc acid hydrochloride and purifying workshop section, 6-aminocaprolc acid and prepare workshop section, each workshop section's step is as described below:
(1), acidolysis workshop section, mass concentration 10-20% aqueous hydrochloric acid is added the top to be had in the enamel reaction still of condensation reflux unit and hydrogen chloride gas absorption unit, mass ratio 100 according to nylon-6 and hydrogenchloride: 25-35 adds nylon-6, under the condition of normal pressure and 100-110 ℃, reacted 6～12 hours, obtain acid hydrolysis solution;
(2), the 6-aminocaprolc acid hydrochloride separates and purifying workshop section, and reactor is vacuumized, and treats that absolute pressure kept later on 20-30 minute less than 10KPa, the acid hydrolysis solution in the step (1) is cooled to 30-40 ℃, uses activated carbon decolorizing behind the filtration residue; The thick 6-aminocaprolc acid hydrochloride solution that obtains, reduction vaporization is concentrated into the 30-40% of cumulative volume, is cooled to 30-45 ℃, filters the thick 6-aminocaprolc acid hydrochloride of separating out, and obtains refining 6-aminocaprolc acid hydrochloride with industrial ethyl alcohol recrystallization, drying;
(3), 6-aminocaprolc acid prepares workshop section, feed ammonia in the thick 6-aminocaprolc acid hydrochloride solution after in step (2), concentrating solution is neutralized to pH3-9, the industrial alcohol that adds 3-5 times of volume, after stirring and being heated to 50-70 ℃, naturally cool to room temperature, the hexosamine that filtration is separated out must be made with extra care 6-aminocaprolc acid after the washing with alcohol drying.
2. a kind of method of producing 6-aminocaprolc acid hydrochloride and 6-aminocaprolc acid with the nylon-6 waste through depolymerization according to claim 1, it is characterized in that the reaction times described in the step (1) is dependent on the property of raw material of nylon-6 waste, when common nylon-6 carpet wool is done raw material, preferred 8 hours.
3. a kind of method of producing 6-aminocaprolc acid hydrochloride and 6-aminocaprolc acid with the nylon-6 waste through depolymerization according to claim 1, it is characterized in that the decolouring employing gac described in the step (2), add-on is the 2-5% of thick 6-aminocaprolc acid hydrochloride solution total mass.
4. a kind of method of producing 6-aminocaprolc acid hydrochloride and 6-aminocaprolc acid with the nylon-6 waste through depolymerization according to claim 1, it is characterized in that the merging of vaporized distillate fluid described in the vacuum Extract described in the hydrogen chloride gas absorption liquid described in the step (1), the step (2), the step (2) and filtrate, reuse is to step (1) after the mensuration acidity.
5. a kind of method of producing 6-aminocaprolc acid hydrochloride and 6-aminocaprolc acid with the nylon-6 waste through depolymerization according to claim 1, it is characterized in that being neutralized to the process of pH value of solution 3-9 with ammonia described in the step (3), be to adopt the strong aqua that adds mass concentration 22-25% to be neutralized to pH value of solution 3-9, and with the extremely near state of doing of solution evaporation, the industrial alcohol that adds 1-3 times of volume while hot, the washing with alcohol drying is used in the crystallization that filtration is separated out, and must make with extra care 6-aminocaprolc acid.
6. a kind of method of producing 6-aminocaprolc acid hydrochloride and 6-aminocaprolc acid with the nylon-6 waste through depolymerization according to claim 1, it is characterized in that the used ethanol of recrystallization described in the step (2), or after used ethanol merges in the strong aqua N-process of used ethanol or 22-25% in the step (3), through rectifying tower distillation back reuse.
7. a kind of method of producing 6-aminocaprolc acid hydrochloride and 6-aminocaprolc acid with the nylon-6 waste through depolymerization according to claim 6, it is characterized in that vinasse after described ethanol is through the rectifying tower distillation is because of containing the not directly waste treatment of a large amount of ammonium chlorides, till needing this moment continuation evaporation concentration to ammonium chloride to begin to separate out, get by-product ammonium chloride behind the naturally cooling filtration drying.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200910097550 CN101857550B (en) | 2009-04-09 | 2009-04-09 | Method for producing 6-aminocaproic acid hydrochloride and 6-aminocaproic acid by using nylon-6 waste through depolymerization |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200910097550 CN101857550B (en) | 2009-04-09 | 2009-04-09 | Method for producing 6-aminocaproic acid hydrochloride and 6-aminocaproic acid by using nylon-6 waste through depolymerization |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101857550A true CN101857550A (en) | 2010-10-13 |
| CN101857550B CN101857550B (en) | 2013-11-06 |
Family
ID=42943742
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200910097550 Expired - Fee Related CN101857550B (en) | 2009-04-09 | 2009-04-09 | Method for producing 6-aminocaproic acid hydrochloride and 6-aminocaproic acid by using nylon-6 waste through depolymerization |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101857550B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102491913A (en) * | 2011-11-28 | 2012-06-13 | 江南大学 | Method for recovering alcoholysis products with catalytic alcoholysis of waste nylon 6 by using binuclear ionic liquid |
| CN111032623A (en) * | 2017-08-25 | 2020-04-17 | 维生源知识产权有限责任公司 | Process for purifying long-chain amino acid |
| CN114166982A (en) * | 2021-11-15 | 2022-03-11 | 北京百奥药业有限责任公司 | Method for simultaneously determining dimer, trimer and caprolactam in amino caproic acid injection |
| CN114195663A (en) * | 2021-12-20 | 2022-03-18 | 昌德新材科技股份有限公司 | Preparation method of 6-aminocaproic acid |
| CN115710198A (en) * | 2022-11-11 | 2023-02-24 | 聊城鲁西聚酰胺新材料科技有限公司 | Method for preparing 6-aminocapronitrile |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2453234A (en) * | 1946-08-14 | 1948-11-09 | American Enka Corp | Process for the preparation of amino-carboxylic-acids from lactams |
| US2930790A (en) * | 1960-03-29 | Process for recovering monomeric | ||
| CN1141290A (en) * | 1995-04-14 | 1997-01-29 | Dsm有限公司 | Depolymerization of polyamides |
-
2009
- 2009-04-09 CN CN 200910097550 patent/CN101857550B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2930790A (en) * | 1960-03-29 | Process for recovering monomeric | ||
| US2453234A (en) * | 1946-08-14 | 1948-11-09 | American Enka Corp | Process for the preparation of amino-carboxylic-acids from lactams |
| CN1141290A (en) * | 1995-04-14 | 1997-01-29 | Dsm有限公司 | Depolymerization of polyamides |
Non-Patent Citations (2)
| Title |
|---|
| 林国权等: "氟哌酸结晶新方法", 《中国医药工业杂志》 * |
| 黄元恺等: "锦纶6废丝水解制ε-氨基己酸新工艺", 《合成纤维》 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102491913A (en) * | 2011-11-28 | 2012-06-13 | 江南大学 | Method for recovering alcoholysis products with catalytic alcoholysis of waste nylon 6 by using binuclear ionic liquid |
| CN111032623A (en) * | 2017-08-25 | 2020-04-17 | 维生源知识产权有限责任公司 | Process for purifying long-chain amino acid |
| CN111032623B (en) * | 2017-08-25 | 2023-02-03 | 维生源知识产权有限责任公司 | Process for purifying long-chain amino acid |
| CN114166982A (en) * | 2021-11-15 | 2022-03-11 | 北京百奥药业有限责任公司 | Method for simultaneously determining dimer, trimer and caprolactam in amino caproic acid injection |
| CN114166982B (en) * | 2021-11-15 | 2023-11-10 | 北京百奥药业有限责任公司 | Method for simultaneously determining dimer, trimer and caprolactam in aminocaproic acid injection |
| CN114195663A (en) * | 2021-12-20 | 2022-03-18 | 昌德新材科技股份有限公司 | Preparation method of 6-aminocaproic acid |
| CN115710198A (en) * | 2022-11-11 | 2023-02-24 | 聊城鲁西聚酰胺新材料科技有限公司 | Method for preparing 6-aminocapronitrile |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101857550B (en) | 2013-11-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101857550B (en) | Method for producing 6-aminocaproic acid hydrochloride and 6-aminocaproic acid by using nylon-6 waste through depolymerization | |
| CN102050781A (en) | Industrial preparation method of hydroxychloroquine sulfate | |
| CN103880690A (en) | Environment-friendly clean production method of glycine | |
| CN101857540A (en) | Method for producing adipic acid, hexamethylenediamine hydrochloride and polyhexamethylene (di)guanidine chloride from nylon-66 through depolymerization | |
| CN103570568A (en) | Clean production process of glycine in coproduction with ammonium chloride | |
| CN105061224A (en) | Synthetic method of L-2-aminobutanol | |
| CN101928202B (en) | Production method of high-purity 3-chloro-1, 2-propanediol | |
| CN1226259C (en) | Preparing method for 1,2-pentadiol | |
| CN101381313B (en) | Synthetic method of electroplating additive N,N-diethyl propargylamine | |
| CN103804267B (en) | A kind of synthesis technique of vildagliptin | |
| CN102391182B (en) | Method for preparing iminodibenzyl | |
| CN102040522A (en) | Method for recycling triethylamine from production of propargite | |
| CN110204418A (en) | A kind of method of highly effective hydrogenation dechlorination purification trichloro-benzenes | |
| CN104710402A (en) | Dicyclohexyl crown ether synthesis method | |
| CN103508982A (en) | Method for separation recovery of cyclohexene oxide from cyclohexanone by-product light oil | |
| CN103788112A (en) | Method for preparing biotin by debenzylating benzyl biotin | |
| CN102241599B (en) | Method for preparing glycine | |
| CN100482630C (en) | Methyl heptenone preparing and refining process | |
| CN105418536A (en) | Method for preparing 2,2'-dithiodibenzothiazole from waste residues generated during process of AE-active ester production | |
| CN104725416A (en) | Continuous separation method and continuous separation device for intermediate methyl diethyl phosphate of glufosinate-ammonium | |
| CN100465149C (en) | Preparation method of chlorophenyl acetic acid | |
| CN102964331B (en) | Synthetic method of piperonylenepropanal | |
| EP2601170A1 (en) | Process for the production of highly pure dicyclohexylamine from by-products resulting from the producton of cyclohexylamine | |
| CN106432089A (en) | Synthetic method of histamine dichloride | |
| CN102002033A (en) | Protection method for astaxanthin intermediate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20131106 Termination date: 20160409 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |