CN117964493A - Synthesis method of N-methyl o-fluoroaniline - Google Patents
Synthesis method of N-methyl o-fluoroaniline Download PDFInfo
- Publication number
- CN117964493A CN117964493A CN202410116203.0A CN202410116203A CN117964493A CN 117964493 A CN117964493 A CN 117964493A CN 202410116203 A CN202410116203 A CN 202410116203A CN 117964493 A CN117964493 A CN 117964493A
- Authority
- CN
- China
- Prior art keywords
- fluoroaniline
- methyl
- reaction
- catalyst
- hydrogen
- 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
- LDVAIJZDACHGML-UHFFFAOYSA-N 2-fluoro-n-methylaniline Chemical compound CNC1=CC=CC=C1F LDVAIJZDACHGML-UHFFFAOYSA-N 0.000 title claims abstract description 29
- 238000001308 synthesis method Methods 0.000 title claims abstract description 8
- FTZQXOJYPFINKJ-UHFFFAOYSA-N 2-fluoroaniline Chemical compound NC1=CC=CC=C1F FTZQXOJYPFINKJ-UHFFFAOYSA-N 0.000 claims abstract description 38
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 claims abstract description 36
- 239000003054 catalyst Substances 0.000 claims abstract description 22
- 239000002994 raw material Substances 0.000 claims abstract description 21
- 238000006243 chemical reaction Methods 0.000 claims abstract description 18
- 230000005494 condensation Effects 0.000 claims abstract description 14
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 13
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 13
- 239000001257 hydrogen Substances 0.000 claims abstract description 13
- 238000006482 condensation reaction Methods 0.000 claims abstract description 11
- 238000000034 method Methods 0.000 claims abstract description 10
- 229910001220 stainless steel Inorganic materials 0.000 claims abstract description 8
- 239000010935 stainless steel Substances 0.000 claims abstract description 8
- 238000009903 catalytic hydrogenation reaction Methods 0.000 claims abstract description 7
- 239000007864 aqueous solution Substances 0.000 claims abstract description 5
- 239000012159 carrier gas Substances 0.000 claims abstract description 3
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 18
- 238000005984 hydrogenation reaction Methods 0.000 claims description 18
- 230000002194 synthesizing effect Effects 0.000 claims description 2
- 239000000575 pesticide Substances 0.000 abstract description 2
- 238000002360 preparation method Methods 0.000 abstract description 2
- 239000002904 solvent Substances 0.000 abstract description 2
- 239000000047 product Substances 0.000 description 16
- MGJURKDLIJVDEO-UHFFFAOYSA-N formaldehyde;hydrate Chemical compound O.O=C MGJURKDLIJVDEO-UHFFFAOYSA-N 0.000 description 7
- 239000006004 Quartz sand Substances 0.000 description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- 230000003197 catalytic effect Effects 0.000 description 6
- 238000001816 cooling Methods 0.000 description 6
- 239000000543 intermediate Substances 0.000 description 6
- 239000007791 liquid phase Substances 0.000 description 6
- 239000002245 particle Substances 0.000 description 6
- 238000009833 condensation Methods 0.000 description 5
- DUMMWWNKDSKGRZ-UHFFFAOYSA-N 2-fluoro-n,n-dimethylaniline Chemical compound CN(C)C1=CC=CC=C1F DUMMWWNKDSKGRZ-UHFFFAOYSA-N 0.000 description 4
- 239000013638 trimer Substances 0.000 description 4
- 239000005588 Oxadiazon Substances 0.000 description 3
- CHNUNORXWHYHNE-UHFFFAOYSA-N Oxadiazon Chemical compound C1=C(Cl)C(OC(C)C)=CC(N2C(OC(=N2)C(C)(C)C)=O)=C1Cl CHNUNORXWHYHNE-UHFFFAOYSA-N 0.000 description 3
- -1 aromatic primary amine Chemical class 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 229930040373 Paraformaldehyde Natural products 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000006555 catalytic reaction Methods 0.000 description 2
- 238000006193 diazotization reaction Methods 0.000 description 2
- 229920002866 paraformaldehyde Polymers 0.000 description 2
- XTFIVUDBNACUBN-UHFFFAOYSA-N 1,3,5-trinitro-1,3,5-triazinane Chemical compound [O-][N+](=O)N1CN([N+]([O-])=O)CN([N+]([O-])=O)C1 XTFIVUDBNACUBN-UHFFFAOYSA-N 0.000 description 1
- 208000005156 Dehydration Diseases 0.000 description 1
- 150000004753 Schiff bases Chemical group 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 238000007098 aminolysis reaction Methods 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 1
- 125000000118 dimethyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 230000002363 herbicidal effect Effects 0.000 description 1
- 239000004009 herbicide Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- LFETXMWECUPHJA-UHFFFAOYSA-N methanamine;hydrate Chemical compound O.NC LFETXMWECUPHJA-UHFFFAOYSA-N 0.000 description 1
- UKVIEHSSVKSQBA-UHFFFAOYSA-N methane;palladium Chemical compound C.[Pd] UKVIEHSSVKSQBA-UHFFFAOYSA-N 0.000 description 1
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- NAGZILFKPSTQBN-UHFFFAOYSA-N n-(2-fluorophenyl)methanimine Chemical compound FC1=CC=CC=C1N=C NAGZILFKPSTQBN-UHFFFAOYSA-N 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
- C07C209/24—Preparation of compounds containing amino groups bound to a carbon skeleton by reductive alkylation of ammonia, amines or compounds having groups reducible to amino groups, with carbonyl compounds
- C07C209/26—Preparation of compounds containing amino groups bound to a carbon skeleton by reductive alkylation of ammonia, amines or compounds having groups reducible to amino groups, with carbonyl compounds by reduction with hydrogen
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/584—Recycling of catalysts
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention belongs to the field of pesticide intermediate preparation, and discloses a synthesis method of N-methyl o-fluoroaniline, which comprises the following steps: pd/C is used as a catalyst, hydrogen is used as a raw material and carrier gas, o-fluoroaniline and formaldehyde aqueous solution are respectively and continuously added into a stainless steel tube type reactor by a metering pump, N-methyl o-fluoroaniline is continuously obtained through condensation and catalytic hydrogenation reaction, and the hydrogen is recycled. The method has the characteristics of relatively mild reaction conditions, high reaction selectivity, high yield, no solvent, environment friendliness and the like.
Description
Technical Field
The invention relates to the technical field of preparation of pesticide intermediates, in particular to a synthesis method of N-methyl o-fluoroaniline.
Background
The N-methyl o-fluoroaniline is a key intermediate for synthesizing herbicide oxadiazon, the main impurities in the N-methyl o-fluoroaniline are o-fluoroaniline and N, N-dimethyl o-fluoroaniline, and particularly the o-fluoroaniline can react with the subsequent intermediate to generate an impurity which is one methyl less than the oxadiazon, and the impurity is difficult to separate from products. Along with the gradual popularization and use of the oxadiazon, the requirement of the high-purity N-methyl o-fluoroaniline is obviously increased.
The methods reported in the current literature mainly comprise the following steps:
Patent CN107973721A discloses a method for obtaining N-methyl o-fluoroaniline by taking o-fluoroaniline, paraformaldehyde and a catalyst A as raw materials, carrying out dehydration treatment after heat preservation reaction, obtaining N-methylene o-fluoroaniline after treatment, and obtaining N-methyl o-fluoroaniline after hydrogenation reaction and post treatment. The invention has poor reaction selectivity, needs further hydrogenation reaction and has the problem of industrial production.
Patent CN109053486a discloses that N-methyl o-fluoroaniline is prepared from o-fluoroaniline by diazotisation and aminolysis. The method adopts diazotization reaction, the diazotization compound is unstable in heat and is easy to explode when heated. Concentrated hydrochloric acid and methylamine water solution are volatile, have strong corrosiveness and severely corrode production equipment.
Patent CN112851518A discloses that N-methyl o-fluoroaniline is obtained by using o-fluoroaniline and dimethyl carbonate as raw materials, catalyzing with alkali, filtering out a catalyst after the reaction is finished, and rectifying filtrate. The synthetic route still has the problem of reaction selectivity, is easy to produce dimethyl byproducts, and the products need to be rectified and purified, and meanwhile, the reaction time is long and the production efficiency is low.
Patent CN109678806a discloses that aromatic primary amine, formaldehyde or paraformaldehyde is used as raw materials, corresponding hexahydro-1, 3, 5-triaryl-1, 3, 5-triazine compounds are obtained through condensation reaction, and monomethylation products of the aromatic primary amine are obtained through hydrogenation reaction under the catalysis of Pd/C.
Disclosure of Invention
CN 109678806A is a superior synthesis method at present by adopting a two-step method of condensation and catalytic hydrogenation of formaldehyde and o-fluoroaniline, and in theory, N-methyl o-fluoroaniline cannot continuously react with formaldehyde, so that the two-step method scheme of o-fluoroaniline and formaldehyde is that N, N-dimethyl o-fluoroaniline cannot be generated. The reaction formula is as follows:
。
The main reason for analyzing the yield of 96% of the patent technical proposal is that o-fluoroaniline and N, N-dimethyl o-fluoroaniline are generated in the hydrogenation process. Through research, the o-fluoroaniline and formaldehyde are condensed, the Schiff base structure is not detected, and all the trimer intermediate is obtained, wherein the reaction formula is as follows:
。
In the catalytic hydrogenation process, the six-membered ring can generate homolytic or heterolytic hydrogenation. Wherein the homolytic hydrogenation is the main part, and the reaction product is N-methyl o-fluoroaniline; after a small amount of hydrogen is subjected to isoschizomer hydrogenation, o-fluoroaniline and N, N-dimethyl o-fluoroaniline are obtained. The reaction formula is as follows:
。
the isoschizomer hydrogenation reaction not only affects the yield but also results in impure products. So patent CN 109678806A reports that the scheme of condensation to obtain the trimer intermediate all first and then catalytic hydrogenation results in 98% of main product content, and the two-step yield is only 96% at maximum. And the rectification separation of the o-fluoroaniline and the N-methyl o-fluoroaniline is difficult, the influence of the o-fluoroaniline on the quality of the subsequent oxazoxamide is large, and the lower the content of the o-fluoroaniline in the product is required to be controlled, the better the content of the o-fluoroaniline in the product is.
Therefore, the key to the improvement of yield and subsequent product quality is to avoid or reduce the formation of trimer by adopting a catalytic hydrogenation method to synthesize N-methyl o-fluoroaniline, and the hydrogenation catalyst in the reaction system is enough relative to the condensation intermediate of o-fluoroaniline and formaldehyde to enable the o-fluoroaniline and formaldehyde to be condensed and then immediately hydrogenated to obtain the product N-methyl o-fluoroaniline.
The invention aims to overcome the defects of the prior art, adopts fixed bed continuous condensation catalysis, adopts o-fluoroaniline and formaldehyde aqueous solution as initial raw materials, adopts a fixed bed tubular reactor filled with Pd/C catalyst, and continuously obtains N-methyl o-fluoroaniline through condensation and catalytic hydrogenation reaction, thereby providing a synthesis method with mild reaction conditions, simple and convenient operation, high reaction selectivity and higher yield.
The technical scheme for realizing the invention is as follows:
① The method comprises the steps of continuously condensing and hydrogenating the raw materials of o-fluoroaniline, formaldehyde aqueous solution and hydrogen which are taken as a reactor and H 2 which is taken as a carrier by taking a fixed bed loaded with a palladium-carbon catalyst to obtain N-methyl o-fluoroaniline;
② The formaldehyde aqueous solution and the o-fluoroaniline are respectively and continuously added into a tubular reactor through a metering pump, and hydrogenation reaction is immediately carried out after condensation, so that the formation of trimer is avoided, and the selectivity of the reaction is improved;
③ The hydrogen is used as carrier gas, no solvent is needed, and the o-fluoroaniline reacts with formaldehyde water to obtain the N-methyl o-fluoroaniline with the content of 99.0-99.5 percent, and the yield is 99.0-99.5 percent (calculated by o-fluoroaniline).
Compared with other synthesis methods, the invention has the following advantages:
1) The raw materials are cheap and easy to obtain, the environment and the operators are relatively friendly, and the production cost is low;
2) The reaction route is short, the operation is simple, and no waste salt exists;
3) The raw materials are added by a pump, and hydrogenation reduction is immediately carried out after the condensation reaction, so that the reaction selectivity is improved;
4) The reaction is solvent-free;
5) The product content is high and is 99.0 to 99.5 percent;
6) The yield is high, and the total yield is 99.0% -99.5% (calculated by o-fluoroaniline).
Detailed Description
Example 1
3.3G of 10% Pd/C particle catalyst was packed in a jacketed stainless steel fixed bed catalytic tube reactor having an inner diameter of 10mm, and the upper and lower ends of the catalyst were filled with a certain amount of quartz sand. The reactor temperature was controlled to 60 ℃. Uniformly feeding 33.3g (0.3 mol) of o-fluoroaniline and 24.6g (0.30 mol) of 37% formaldehyde water into a tubular reactor for 4 hours, controlling the flow rate of hydrogen to be 90mL/min, carrying out condensation and hydrogenation reaction on the raw materials, and cooling and dehydrating the raw materials by a cooler to obtain 37.5g of the product N-methyl o-fluoroaniline, wherein the liquid phase is quantitative, the content is 99.0%, and the yield is 99.0% (calculated by o-fluoroaniline).
Example 2
3.3G of 10% Pd/C particle catalyst was packed in a jacketed stainless steel fixed bed catalytic tube reactor having an inner diameter of 10mm, and the upper and lower ends of the catalyst were filled with a certain amount of quartz sand. The reactor temperature was controlled to 90 ℃. Uniformly feeding 33.3g (0.3 mol) of o-fluoroaniline and 24.6g (0.30 mol) of 37% formaldehyde water into a tubular reactor for 4 hours, controlling the flow rate of hydrogen to be 90mL/min, carrying out condensation and hydrogenation reaction on the raw materials, and cooling and dehydrating the raw materials by a cooler to obtain 37.6g of the product N-methyl o-fluoroaniline, wherein the liquid phase is quantitative, the content is 99.1%, and the yield is 99.3% (calculated by o-fluoroaniline).
Example 3
5.0G of 15% Pd/C particle catalyst was packed in a jacketed stainless steel fixed bed catalytic tube reactor having an inner diameter of 10mm, and the upper and lower ends of the catalyst were filled with a certain amount of quartz sand. The reactor temperature was controlled to 75 ℃. Uniformly feeding 33.3g (0.3 mol) of o-fluoroaniline and 24.6g (0.30 mol) of 37% formaldehyde water into a tubular reactor for 4 hours, controlling the flow rate of hydrogen to be 90mL/min, carrying out condensation and hydrogenation reaction on the raw materials, and cooling and dehydrating the raw materials by a cooler to obtain 37.5g of the product N-methyl o-fluoroaniline, wherein the liquid phase is quantitative, the content is 99.2%, and the yield is 99.2% (calculated by o-fluoroaniline).
Example 4
5.0G of 15% Pd/C particle catalyst was packed in a jacketed stainless steel fixed bed catalytic tube reactor having an inner diameter of 10mm, and the upper and lower ends of the catalyst were filled with a certain amount of quartz sand. The reactor temperature was controlled to 90 ℃. Uniformly feeding 33.3g (0.3 mol) of o-fluoroaniline and 25.8g (0.32 mol) of 37% formaldehyde water into a tubular reactor for 4 hours, controlling the flow rate of hydrogen to be 150mL/min, carrying out condensation and hydrogenation reaction on the raw materials, and cooling and dehydrating the raw materials by a cooler to obtain 37.7g of the product N-methyl o-fluoroaniline, wherein the liquid phase is quantitative, the content is 99.3%, and the yield is 99.5% (calculated by o-fluoroaniline).
Example 5
5.0G of 15% Pd/C particle catalyst was packed in a jacketed stainless steel fixed bed catalytic tube reactor having an inner diameter of 10mm, and the upper and lower ends of the catalyst were filled with a certain amount of quartz sand. The reactor temperature was controlled to 90 ℃. Uniformly feeding 33.3g (0.3 mol) of o-fluoroaniline and 25.1g (0.31 mol) of 37% formaldehyde water into a tubular reactor for 4 hours, controlling the flow rate of hydrogen to be 180mL/min, carrying out condensation and hydrogenation reaction on the raw materials, and cooling and dehydrating the raw materials by a cooler to obtain 37.5g of the product N-methyl o-fluoroaniline, wherein the liquid phase is quantitative, the content is 99.5%, and the yield is 99.4% (calculated by o-fluoroaniline).
Example 6
4.3G of 13% Pd/C particle catalyst was packed in a jacketed stainless steel fixed bed catalytic tube reactor having an inner diameter of 10mm, and the upper and lower ends of the catalyst were filled with a certain amount of quartz sand. The reactor temperature was controlled to 60 ℃. Uniformly feeding 33.3g (0.3 mol) of o-fluoroaniline and 24.6g (0.3 mol) of 37% formaldehyde water into a tubular reactor for 4 hours, controlling the flow rate of hydrogen to be 120mL/min, carrying out condensation and hydrogenation reaction on the raw materials, and cooling and dehydrating the raw materials by a cooler to obtain 37.5g of the product N-methyl o-fluoroaniline, wherein the liquid phase is quantitative, the content is 99.2%, and the yield is 99.3% (calculated by o-fluoroaniline).
The above description is merely a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above examples. All technical schemes belonging to the concept of the invention belong to the protection scope of the invention. It should be noted that modifications and adaptations to the present invention without departing from its principles are intended to be within the scope of the present invention as set forth in the following claims.
Claims (2)
1. A synthesis method of N-methyl o-fluoroaniline is characterized in that: the Pd/C catalyst is filled in the stainless steel tube type reactor, hydrogen is used as a raw material and carrier gas, o-fluoroaniline and 37% formaldehyde aqueous solution are respectively and continuously added into the reactor by a metering pump, and N-methyl o-fluoroaniline is continuously obtained through condensation and catalytic hydrogenation reaction, wherein the reaction formula is as follows:
。
2. the method for synthesizing N-methyl o-fluoroaniline according to claim 1, wherein the hydrogenation catalyst is Pd/C, the average load of the catalyst is 3.0g o-fluoroaniline/g catalyst.h, the reaction temperature is 60-90 ℃, and the molar ratio of o-fluoroaniline to formaldehyde to hydrogen is 1:1.01:3-1:1.06:6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410116203.0A CN117964493A (en) | 2024-01-29 | 2024-01-29 | Synthesis method of N-methyl o-fluoroaniline |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410116203.0A CN117964493A (en) | 2024-01-29 | 2024-01-29 | Synthesis method of N-methyl o-fluoroaniline |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117964493A true CN117964493A (en) | 2024-05-03 |
Family
ID=90845256
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410116203.0A Pending CN117964493A (en) | 2024-01-29 | 2024-01-29 | Synthesis method of N-methyl o-fluoroaniline |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117964493A (en) |
-
2024
- 2024-01-29 CN CN202410116203.0A patent/CN117964493A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111004148B (en) | Method for preparing 6-aminocapronitrile by gas phase method | |
| KR102061868B1 (en) | Method for preparing azoxystrobin intermediates | |
| CN106488905B (en) | Process for producing aromatic primary diamines | |
| EP2257521B1 (en) | Method for making methylpentamethylene diamine and methylpiperidine | |
| CN114031551A (en) | Fluopyram and synthesis method thereof | |
| CA3171450A1 (en) | System of preparing a phthalonitrile-based compound and method of preparing phthalonitrile-based compound using the same | |
| CN111689893B (en) | Preparation method of 2,2,6, 6-tetramethyl-4-aminopiperidine | |
| CN117964493A (en) | Synthesis method of N-methyl o-fluoroaniline | |
| CN109761819B (en) | Continuous preparation method of N, N-dimethylpropylamine | |
| CN112724064A (en) | Method for preparing 5, 6-dihydroxyindole by using modified ordered mesoporous carbon supported metal catalyst | |
| CN111138351A (en) | Synthetic method of 2-aminomethyl-3-chloro-5-trifluoromethylpyridine acetate | |
| JP4424479B2 (en) | Method for producing xylylenediamine | |
| CN113563225B (en) | Method for synthesizing benzonitrile by recycling benzomelamine byproduct | |
| US20090076306A1 (en) | Process for continuous preparation of a primary aromatic amine | |
| CN115466249A (en) | Preparation method of flumioxazin | |
| CN111644196B (en) | High-selectivity preparation method of methylpentamethylenediamine by adopting composite catalytic system | |
| JP2004035427A (en) | Method for producing xylylenediamine and/or cyanobenzylamine | |
| CN114933532A (en) | Method for continuously synthesizing 2-n-butyl ethyl acetoacetate by using fixed bed | |
| CN107628957A (en) | A kind of new method research of the direct ammonification synthesizing cyclohexane 1 amine of cyclohexene | |
| CN112279781A (en) | Synthetic method of p-hydroxybenzonitrile | |
| CN112624958A (en) | Synthetic method of medical intermediate 1, 2-cyclopentadienimide | |
| CN102173993B (en) | Method for synthesizing 4,6-diamino resorcinol dihydrochloride (DAR) | |
| CN112209839A (en) | Method for synthesizing 2, 2-difluoroethylamine by using high-boiling-point substance in R142b as raw material | |
| CN107089918B (en) | Preparation method of benzhydrylamine hydrochloride | |
| CN118546084B (en) | Alcohol amine method for co-production of indole and N-methylindole and separation and purification method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |