CN111153854A - Preparation method of 2-methylquinoline - Google Patents
Preparation method of 2-methylquinoline Download PDFInfo
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- CN111153854A CN111153854A CN202010039382.4A CN202010039382A CN111153854A CN 111153854 A CN111153854 A CN 111153854A CN 202010039382 A CN202010039382 A CN 202010039382A CN 111153854 A CN111153854 A CN 111153854A
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- C07D215/00—Heterocyclic compounds containing quinoline or hydrogenated quinoline ring systems
- C07D215/02—Heterocyclic compounds containing quinoline or hydrogenated quinoline ring systems having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen atoms or carbon atoms directly attached to the ring nitrogen atom
- C07D215/04—Heterocyclic compounds containing quinoline or hydrogenated quinoline ring systems having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen atoms or carbon atoms directly attached to the ring nitrogen atom with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, directly attached to the ring carbon atoms
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Abstract
The invention discloses a preparation method of 2-methylquinoline, which comprises the following synthesis steps: in the presence of an oxidant, adding a catalyst and an auxiliary agent, and adding nitrobenzene and ethanol for one-step reaction to prepare a 2-methylquinoline target product; wherein the catalyst comprises a metal catalyst, an auxiliary agent I and an auxiliary agent II; the metal catalyst is a palladium metal catalyst; the auxiliary agent I is a silver-containing compound; the adjuvant II is an acidic compound. According to the invention, nitrobenzene and ethanol are used as raw materials, and 2-methylquinoline can be prepared through one-step reaction by the method, so that the preparation method is simple and easy to implement; the preparation process does not generate new three wastes, is environment-friendly, and provides a green and environment-friendly synthetic method for adapting to the development of times; the preparation method has the advantages of fewer raw material types, fewer reaction equipment, fewer preparation steps and lower cost, and is more suitable for industrial production.
Description
Technical Field
The invention belongs to the technical field of organic intermediates, and particularly relates to a preparation method of 2-methylquinoline.
Background
2-methylquinoline, also known as quinaldine, has the molecular formula of C10H9N, and is a colorless oily liquid. Dissolving in ethanol, diethyl ether, acetone and chloroform, and slightly dissolving in water. 2-methylquinoline is an important organic chemical intermediate, and is widely used for preparing alkali-increasing agent, photographic sensitizer, rubber vulcanization accelerator, lubricant antioxidant, pesticide, bactericide, dye and the like of color cinematographic film.
At present, two main ways exist for the industrial production of 2-methylquinoline compounds: coal tar extraction and chemical synthesis.
The coal tar extraction method is characterized in that coal tar or isoquinoline kettle residue (fraction) is used as a raw material, and 2-methylquinoline with high purity can be obtained through the steps of extraction by a phosphate double salt method, recrystallization, rectification, purification and the like. However, the method produces a large amount of wastewater pollution and the product yield is not high.
The chemical synthesis methods mainly include Skraup, Combes, Conrad-Limpach-Knorr, Friedlander, Doebner-Von Miller and the like. The Skraup process is widely used for preparing various quinoline derivatives. Heating arylamine, concentrated sulfuric acid, glycerol and an oxidant together to obtain a quinoline derivative (Skraup, Z.H.Ber.1880, 13, 2086.). In the reaction process, glycerin is dehydrated by concentrated sulfuric acid at high temperature to produce acrolein, and the acrolein and aniline are condensed to form dihydroquinoline, and finally the dihydroquinoline is oxidized to obtain the product quinoline. The Skraup reaction is carried out at high temperature under concentrated sulfuric acid, and raw materials which are unstable and easy to react are not suitable for the method under the reaction condition. In addition to this disadvantage, the Skraup process is a very good method for preparing quinoline derivatives and is widely used. The subsequent modified Skraup-Doebner-Von Miller quinoline synthesis process replaces glycerol with acrolein, reducing the step of preparing acrolein with glycerol. Although the Skraup-Doebner-Von Miller quinoline synthesis method is a widely used reaction in organic synthesis, the reaction still needs to be carried out at a high temperature. Many reaction raw materials are not suitable under the reaction condition, and inorganic liquid acid and alkali are used in a large amount, so that a large amount of waste is generated, and the reaction yield is not high. Other synthesis methods of quinoline such as Combes, Conrad-Limpach-Knorr have special requirements on reaction substrates. Substrates containing carbonylaniline and substrates containing carbonyl building blocks are necessary, and the reaction is also most often carried out in strongly acidic or strongly basic media. These conditions also limit their further applications.
Although the above chemical synthesis methods have respective disadvantages, they have the same disadvantages, and require the use of a large amount of strong acid or strong base. There are also many limitations on the structure of the reaction substrate. Based on the problems in the traditional quinoline synthesis method, the method for preparing the quinoline derivative by the catalysis of the transition metal can avoid the use of strong acid and strong base, and simultaneously has simple substrateIs easy to obtain. And therefore are receiving increasing attention. Cho et al with RuCl3·nH2O is catalyst, by adding SnCl2·2H2O enables the reaction of aniline with tertiary amines and olefins to prepare quinoline derivatives (chem. commun, 2000, 19, 885-1886.OrgLett, 2005, 7, 2181-. Watanabe et al found that aniline and aliphatic aldehyde can undergo a Doebner-Von Miller reaction to obtain quinoline compounds (Bull. chem. Soc. Jpn, 1978, 51, 3397-3398.) under the action of a rhodium complex catalyst. Compared with the traditional method, the method for preparing the 2-methylquinoline by the transition metal catalysis has great improvement, but still has the problems of difficult catalyst, poor substrate applicability, poor reaction selectivity and the like.
In summary, in the existing technology for synthesizing 2-methylquinoline by chemical synthesis, aniline and fatty aldehyde, simple alcohol, fatty amine and olefin are mainly used as raw materials. And generally needs to be in strong acid, high temperature and high pressure environment, the reaction condition is harsh, the process is complex, and the method is not environment-friendly. Therefore, the search for a method for preparing 2-methylquinoline, which has simple process conditions, is environment-friendly, and has simple and easily available starting materials, is still a research hotspot in the field.
Disclosure of Invention
The invention provides a preparation method of 2-methylquinoline aiming at the technical problems in the prior art, the method takes nitrobenzene and ethanol as raw materials, and the 2-methylquinoline can be prepared through one-step reaction, and the preparation method is simple and easy to implement.
The technical scheme adopted by the invention is as follows: a preparation method of 2-methylquinoline comprises the following synthesis steps: in the presence of an oxidant, adding a catalyst and an auxiliary agent, and adding nitrobenzene and ethanol for one-step reaction to prepare a 2-methylquinoline target product;
wherein the catalyst comprises a metal catalyst, an auxiliary agent I and an auxiliary agent II;
the metal catalyst is a palladium metal catalyst;
the auxiliary agent I is a silver-containing compound;
the adjuvant II is an acidic compound.
Preferably, the palladium metal catalyst comprises one or more of palladium on carbon, palladium acetate, palladium hydroxide, palladium chloride, tetratriphenylphosphine palladium, tris (dibenzylideneacetone) dipalladium, allylpalladium (II) chloride dimer, or palladium trifluoroacetate.
Preferably, the palladium metal catalyst is used in an amount of 1 to 5% by mol.
Preferably, the adjuvant I comprises one or more of silver hexafluoroantimonate, silver carbonate, silver sulfate, silver tetrafluoroborate, silver nitrate, silver phosphate, silver acetate, silver bromide, silver chloride, silver fluoride, silver trifluoroacetate, silver trifluoromethanesulfonate or bis-trifluoromethanesulfonylimide silver salt.
Preferably, the adjuvant I is used in an amount of 50 to 200 mol%.
Preferably, the adjuvant II comprises one or more of toluene sulfonic acid, trifluoroacetic acid, acetic acid, chloroacetic acid, pivalic acid, methanesulfonic acid, trifluoromethanesulfonic acid, acetic anhydride or trifluoroacetic anhydride.
Preferably, the adjuvant II is used in an amount of 20 to 200 mol%.
Preferably, the oxidant comprises one of oxygen or air.
Preferably, the reaction temperature is 100-180 ℃, and the reaction time is 24 h.
The reaction formula for preparing the 2-methylquinoline is as follows:
compared with the prior art, the invention has the beneficial effects that: according to the invention, nitrobenzene and ethanol are used as raw materials, and 2-methylquinoline can be prepared through one-step reaction by the method, so that the preparation method is simple and easy to implement; the preparation process does not generate new three wastes, is environment-friendly, and provides a green and environment-friendly synthetic method for adapting to the development of times; the preparation method has the advantages of fewer raw material types, fewer reaction equipment, fewer preparation steps and lower cost, and is more suitable for industrial production.
Drawings
FIG. 1 is a drawing showing 2-methylquinoline prepared in example 1 of the present invention1H-NMR；
FIG. 2 is a diagram of 2-methylquinoline prepared in example 1 of the present invention13C-NMR。
Detailed Description
In order to make the technical solutions of the present invention better understood, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
Example 1
Accurately weighing 0.005mmol of palladium acetate catalyst, adding 10mL of the palladium acetate catalyst into a Young reaction tube which is placed in a magnetic stirrer, carrying out oxygen replacement three times in the Young reaction tube to ensure that the reaction is carried out under the oxygen condition, accurately adding 0.4mmol of silver tetrafluoroborate, 0.1mmol of pivalic acid, 0.2mmol of nitrobenzene and 1mL of ethanol into the Young reaction tube by using an injector, placing the Young reaction tube on the magnetic stirrer, and stirring for 24 hours at 180 ℃; after the reaction is finished, performing column chromatography on the reaction solution to obtain a pure product of the 2-methylquinoline, wherein the yield is 81%.
The 2-methylquinoline obtained above was subjected to characterization tests:
the method can prepare 2-methylquinoline as shown in figure 11H-NMR, compound characterization data:1H-NMR(400MHz，CDCl3)：δ(ppm)＝2.65(s，3.0H)，7.10(d，J＝8.0Hz，1.0H)，7.38(m，1.0H)，7.58(m，1.0H)，7.86(d，J＝8.0Hz，1.0H)，8.00(d，J＝12Hz，1.0H)。
the method can prepare 2-methylquinoline as shown in figure 213C-NMR, compound characterization data:
13C-NMR(100MHz，CDCl3)：δ(ppm)＝158.80，147.75，136.01，129.30，128.51，127.41，126.37，125.54，121.85，25.26。
example 2
Accurately weighing 0.005mmol of palladium acetate catalyst, adding 10mL of Young's reaction tube which is already placed in a magnetic stirrer, accurately adding 0.4mmol of silver tetrafluoroborate, 0.1mmol of pivalic acid, 0.2mmol of nitrobenzene and 1mL of ethanol into the Young's reaction tube by using an injector, placing the Young's reaction tube on a magnetic stirrer, and stirring for 24 hours at the temperature of 100 ℃; after the reaction is finished, performing column chromatography on the reaction solution to obtain a pure product of the 2-methylquinoline, wherein the yield is 32%.
Example 3
Accurately weighing 0.01mmol of palladium acetate catalyst, adding 10mL of the palladium acetate catalyst into a Young reaction tube which is placed in a magnetic stirrer, carrying out oxygen replacement three times in the Young reaction tube to ensure that the reaction is carried out under the oxygen condition, accurately adding 0.4mmol of silver acetate, 0.2mmol of trifluoroacetic acid, 0.2mmol of nitrobenzene and 1mL of ethanol into the Young reaction tube by using a syringe, placing the Young reaction tube on the magnetic stirrer, and stirring for 24 hours at the temperature of 140 ℃; after the reaction is finished, performing column chromatography on the reaction solution to obtain a pure product of the 2-methylquinoline, wherein the yield is 68%.
Example 4
Accurately weighing 0.005mmol of palladium chloride catalyst, adding 10mL of the palladium chloride catalyst into a Young reaction tube which is placed in a magnetic stirrer, carrying out oxygen replacement three times in the Young reaction tube to ensure that the reaction is carried out under the oxygen condition, accurately adding 0.1mmol of silver tetrafluoroborate, 0.4mmol of trifluoroacetic acid, 0.2mmol of nitrobenzene and 1mL of ethanol into the Young reaction tube by using an injector, placing the Young reaction tube on the magnetic stirrer, and stirring for 24 hours at 180 ℃; after the reaction is finished, performing column chromatography on the reaction solution to obtain a pure product of the 2-methylquinoline, wherein the yield is 75%.
Example 5
Accurately weighing 0.005mmol of palladium chloride catalyst, adding 10mL of the palladium chloride catalyst into a Young reaction tube which is placed in a magnetic stirrer, carrying out oxygen replacement three times in the Young reaction tube to ensure that the reaction is carried out under the oxygen condition, accurately adding 0.4mmol of silver tetrafluoroborate, 0.04mmol of acetic acid, 0.2mmol of nitrobenzene and 1mL of ethanol into the Young reaction tube by using an injector, placing the Young reaction tube on the magnetic stirrer, and stirring for 24 hours at 180 ℃; after the reaction is finished, performing column chromatography on the reaction solution to obtain a pure product of the 2-methylquinoline, wherein the yield is 65%.
Example 6
Accurately weighing 0.002mmol palladium chloride and 0.003 mmol tetratriphenylphosphine palladium catalyst, adding 10mL of Young reaction tube which is already placed in a magnetic stirrer, carrying out oxygen replacement three times in the Young reaction tube to ensure that the reaction is carried out under the oxygen condition, accurately adding 0.2mmol silver carbonate, 0.2mmol chloroacetic acid, 0.2mmol nitrobenzene and 1mL ethanol into the Young reaction tube by using an injector, placing the Young reaction tube on the magnetic stirrer, and stirring for 24 hours at 180 ℃; after the reaction is finished, performing column chromatography on the reaction solution to obtain a pure product of the 2-methylquinoline, wherein the yield is 72%.
Example 7
Accurately weighing 0.002mmol of palladium acetate catalyst, adding 10mL of the palladium acetate catalyst into a Young reaction tube which is placed in a magnetic stirrer, carrying out oxygen replacement three times in the Young reaction tube to ensure that the reaction is carried out under the oxygen condition, accurately adding 0.4mmol of bis (trifluoromethane) sulfimide silver salt, 0.1mmol of pivalic acid, 0.2mmol of nitrobenzene and 1mL of ethanol into the Young reaction tube by using an injector, placing the Young reaction tube on the magnetic stirrer, and stirring for 24 hours at 180 ℃; after the reaction is finished, performing column chromatography on the reaction solution to obtain a pure product of the 2-methylquinoline, wherein the yield is 60%.
The present invention has been described in detail with reference to the embodiments, but the description is only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The scope of the invention is defined by the claims. The technical solutions of the present invention or those skilled in the art, based on the teaching of the technical solutions of the present invention, should be considered to be within the scope of the present invention, and all equivalent changes and modifications made within the scope of the present invention or equivalent technical solutions designed to achieve the above technical effects are also within the scope of the present invention.
Claims (9)
1. A preparation method of 2-methylquinoline is characterized in that: comprises the following synthesis steps: in the presence of an oxidant, adding a catalyst and an auxiliary agent, and adding nitrobenzene and ethanol for one-step reaction to prepare a 2-methylquinoline target product;
wherein the catalyst comprises a metal catalyst, an auxiliary agent I and an auxiliary agent II;
the metal catalyst is a palladium metal catalyst;
the auxiliary agent I is a silver-containing compound;
the adjuvant II is an acidic compound.
2. The process for the preparation of 2-methylquinoline as claimed in claim 1, characterized in that: the palladium metal catalyst comprises one or more of palladium on carbon, palladium acetate, palladium hydroxide, palladium chloride, tetratriphenylphosphine palladium, tris (dibenzylideneacetone), dipalladium, allylpalladium (II) chloride dimer, or palladium trifluoroacetate.
3. The process for the preparation of 2-methylquinoline as claimed in claim 1, characterized in that: the dosage of the palladium metal catalyst is 1-5% mol.
4. The process for the preparation of 2-methylquinoline as claimed in claim 1, characterized in that: the auxiliary agent I comprises one or more of silver hexafluoroantimonate, silver carbonate, silver sulfate, silver tetrafluoroborate, silver nitrate, silver phosphate, silver acetate, silver bromide, silver chloride, silver fluoride, silver trifluoroacetate, silver trifluoromethanesulfonate or bis-trifluoromethanesulfonylimide silver salt.
5. The process for the preparation of 2-methylquinoline as claimed in claim 1, characterized in that: the dosage of the adjuvant I is 50-200 mol%.
6. The process for the preparation of 2-methylquinoline as claimed in claim 1, characterized in that: the auxiliary II comprises one or more of toluenesulfonic acid, trifluoroacetic acid, acetic acid, chloroacetic acid, pivalic acid, methanesulfonic acid, trifluoromethanesulfonic acid, acetic anhydride or trifluoroacetic anhydride.
7. The process for the preparation of 2-methylquinoline as claimed in claim 1, characterized in that: the dosage of the adjuvant II is 20-200 mol%.
8. The process for the preparation of 2-methylquinoline as claimed in claim 1, characterized in that: the oxidant comprises one of oxygen or air.
9. The process for the preparation of 2-methylquinoline as claimed in claim 1, characterized in that: the reaction temperature is 100-180 ℃, and the reaction time is 24 h.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007060685A1 (en) * | 2005-11-25 | 2007-05-31 | Council Of Scientific & Industrial Research | An improved process for the synthesis of quinoline derivatives |
| CN101805287A (en) * | 2010-04-01 | 2010-08-18 | 浙江工业大学 | Method for one-pot liquid phase synthesis of quinoline and derivative thereof |
| CN102898366A (en) * | 2012-03-30 | 2013-01-30 | 浙江工业大学 | Method for one-step preparation of 2-methylquinoline |
| CN106543078A (en) * | 2016-07-21 | 2017-03-29 | 中国科学院兰州化学物理研究所苏州研究院 | A kind of preparation method of quinoline |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007060685A1 (en) * | 2005-11-25 | 2007-05-31 | Council Of Scientific & Industrial Research | An improved process for the synthesis of quinoline derivatives |
| CN101805287A (en) * | 2010-04-01 | 2010-08-18 | 浙江工业大学 | Method for one-pot liquid phase synthesis of quinoline and derivative thereof |
| CN102898366A (en) * | 2012-03-30 | 2013-01-30 | 浙江工业大学 | Method for one-step preparation of 2-methylquinoline |
| CN106543078A (en) * | 2016-07-21 | 2017-03-29 | 中国科学院兰州化学物理研究所苏州研究院 | A kind of preparation method of quinoline |
Non-Patent Citations (5)
| Title |
|---|
| JIXING LI ET AL.: "Assembly of Diversely Substituted Quinolines via Aerobic Oxidative Aromatization from Simple Alcohols and Anilines", 《THE JOURNAL OF ORGANIC CHEMISTRY》 * |
| K.SELVAM ET AL.: "Cost effective one-pot photocatalytic synthesis of quinaldines from nitroarenes by silver loaded TiO2", 《JOURNAL OF MOLECULAR CATALYSIS A:CHEMICAL》 * |
| KALIYAMOORTHY SELVAM: "Nano N-TiO2 mediated selective photocatalytic synthesis of quinaldines from nitrobenzenes", 《RSC ADVANCES》 * |
| KALIYAMOORTHY SELVAN ET AL.: "Novel Redox Photocatalyst Pt–TiO2 for the Synthesis of 2-Methylquinolines from Nitroarenes", 《BULL.CHEM.SOC.JPN》 * |
| LIN HE ET AL.: "Titania‐Supported Iridium Subnanoclusters as an Efficient Heterogeneous Catalyst for Direct Synthesis of Quinolines from Nitroarenes and Aliphatic Alcohols", 《ANGEW.CHEM.INT.ED.》 * |
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