CN111569947A - Method for synthesizing 2-methylpyridine organic cobalt catalyst - Google Patents
Method for synthesizing 2-methylpyridine organic cobalt catalyst Download PDFInfo
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- CN111569947A CN111569947A CN202010567341.2A CN202010567341A CN111569947A CN 111569947 A CN111569947 A CN 111569947A CN 202010567341 A CN202010567341 A CN 202010567341A CN 111569947 A CN111569947 A CN 111569947A
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- cobalt catalyst
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- methylpyridine
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
- B01J31/16—Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes
- B01J31/22—Organic complexes
- B01J31/2282—Unsaturated compounds used as ligands
- B01J31/2295—Cyclic compounds, e.g. cyclopentadienyls
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
- C07D213/04—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D213/06—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom containing only hydrogen and carbon atoms in addition to the ring nitrogen atom
- C07D213/16—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom containing only hydrogen and carbon atoms in addition to the ring nitrogen atom containing only one pyridine ring
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
- C07F17/00—Metallocenes
- C07F17/02—Metallocenes of metals of Groups 8, 9 or 10 of the Periodic System
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2531/00—Additional information regarding catalytic systems classified in B01J31/00
- B01J2531/80—Complexes comprising metals of Group VIII as the central metal
- B01J2531/84—Metals of the iron group
- B01J2531/845—Cobalt
Abstract
The invention discloses a method for synthesizing a 2-methylpyridine organic cobalt catalyst, which comprises the following steps: step 1: selecting sodium carbonate as alkali, placing cobalt chloride, cyclopentadiene and sodium carbonate in N, N-dimethylformamide for high-temperature reaction, and coordinating cyclopentadiene with cobalt chloride under alkaline condition to generate an organic cobalt catalyst; step 2: dissolving the generated organic cobalt catalyst in N, N-dimethylformamide, evaporating the N, N-dimethylformamide through reduced pressure distillation, adding water and dichloromethane, dissolving sodium chloride in the water, separating after layering, reducing the salt content in the organic solvent through repeated extraction operation, putting the obtained dichloromethane solution into a low-temperature environment, slowly separating out the organic cobalt catalyst, separating out crystals, and obtaining the high-purity organic cobalt catalyst through suction filtration and drying. The invention obtains the needed organic cobalt catalyst through one-step reaction, and can improve the purity of the final product through a crystallization method.
Description
Technical Field
The invention relates to a catalyst synthesis method, in particular to a method for synthesizing a 2-methylpyridine organic cobalt catalyst.
Background
The 2-methylpyridine is also called alpha-methylpyridine and is mainly used for preparing raw materials of gum dipping butadiene-pyridine latex of rubber framework materials, namely 2-vinylpyridine and 2-methyl-5-vinylpyridine; it can also be used for preparing nitrogen fertilizer synergist (N-Serve), livestock anthelmintic, poultry medicine, film sensitizer additive, dye intermediate, rubber accelerator, etc.; as an experimental reagent for assaying cobalt, cyanate and iron; the preparation method is used for preparing medicaments such as the SICANI, the chlorpheniramine, the pralidoxime chloride, the acetylcysteine, the long-acting sulfanilamide and the like in medicine; 2-methylpyridine is used as a raw material to synthesize important pesticide intermediates such as 2-hydroxy-3, 5, 6-trichloropyridine, 2-trifluoromethyl-6-chloropyridine and the like on pesticides; the 2-methylpyridine can also be used for synthesizing important fine chemical intermediates such as 2-cyanopyridine, 2-pyridinemethanol, 2-pyridinecarboxaldehyde, 2-picolinate and the like.
Currently, an organocobalt catalyst method for synthesizing 2-picoline is disclosed in a catalyst preparation method (cn200710143936.x) for synthesizing 2-picoline. The latest synthesis method is as follows: adding tetrahydrofuran and sodium amide into a reaction kettle, dripping cyclopentadiene at the temperature of 0-45 ℃, keeping for 0.5-3 h to prepare cyclopentadienyl sodium, keeping refluxing at the temperature of 60-70 ℃, continuously stirring for reaction for 1-2 h, completing the preparation of the catalyst, distilling to recover the solvent, and adding acetonitrile to obtain the catalyst in a mixture state. The method has the main defects of complicated operation steps, large step-by-step reaction loss and low yield. Finally, the organic cobalt catalyst crystal obtained by removing metal salts such as sodium chloride and the like is not high in purity and not ideal in catalytic effect.
Disclosure of Invention
The invention aims to provide a method for synthesizing a 2-methylpyridine organic cobalt catalyst, which can obtain the required organic cobalt catalyst through one-step reaction, can improve the purity of a final product through a crystallization method, reduces operation steps for solving the problem of step-by-step synthesis, improves the purity of the organic cobalt catalyst product so as to improve the reaction efficiency, and can solve the problems provided by the background technology.
In order to achieve the purpose, the invention provides the following technical scheme:
a method for synthesizing a 2-methylpyridine organic cobalt catalyst comprises the following steps:
step 1: selecting sodium carbonate as alkali, placing cobalt chloride, cyclopentadiene and sodium carbonate in N, N-dimethylformamide for high-temperature reaction, and coordinating cyclopentadiene with cobalt chloride under alkaline condition to generate an organic cobalt catalyst;
step 2: the produced organic cobalt catalyst is dissolved in N, N-dimethylformamide, and the inside thereof also contains a salt such as sodium chloride dissolved in water. After the N, N-dimethylformamide is distilled off by reduced pressure distillation, water and salts such as dichloromethane, sodium chloride and the like are added and dissolved in the water, the organic cobalt catalyst is easily dissolved in the dichloromethane, the organic cobalt catalyst can be separated after delamination, and the salt content in the organic solvent is reduced by repeated extraction operation. The obtained dichloromethane solution is put into a low-temperature environment, the organic cobalt catalyst can be slowly separated out, and the purity of the organic cobalt catalyst is improved. And (4) carrying out suction filtration and drying on the precipitated crystals to obtain the high-purity organic cobalt catalyst.
Further, the synthesis reaction of step 1 is carried out under alkaline conditions, using sodium carbonate as base, the molar ratio of sodium carbonate to cyclopentadiene and cobalt chloride hexahydrate being between 1.2:2:1.2 and 1.8:2: 1.8.
Further, the N, N-dimethylformamide in the step 1 is used as a synthesis reaction solvent, and the mass ratio of the solvent amount to the cobalt chloride is 5.4-8.5.
Further, the synthesis reaction temperature of the step 1 is 90-100 ℃, and the reaction time is 8-10 h.
And further, after the reaction in the step 2, dichloromethane and water are adopted for dissolving and extracting, extraction is carried out for 2-3 times, and then sodium sulfate aqueous solution is added to extract impurities of an organic phase, wherein the concentration of the sodium sulfate solution is 21.9-25%.
Further, in the step 2, in the post-treatment, the dichloromethane solution obtained by extraction is placed in the environment of low temperature of-5 to 0 ℃ for cooling and crystallization, and the crystallization time is 7 to 8 hours.
Further, filtering the solution after crystallization in the reaction post-treatment in the step 2 at a low temperature, wherein the drying temperature of the filtered solid is 50-60 ℃.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention adopts a one-step synthesis reaction, reduces the synthesis steps and has simple operation.
2. The invention adopts a low-temperature crystallization mode, and improves the purity of the catalyst.
3. The invention adopts sodium carbonate as alkali, reduces cost and solves the problem that sodium amide is easy to decompose as alkali.
4. The method adopts an extraction mode to remove metal salts such as sodium chloride and the like, has less residual metal salts, and reduces the influence of the metal salts on the structure of the synthesized catalyst.
5. The invention adopts dichloromethane as a crystallization solvent, the dichloromethane has low boiling point and high solubility, and is immiscible with water, so that the loss of the catalyst can be reduced, and meanwhile, the drying speed is high, the influence of water is reduced, and the yield is improved.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
A method for synthesizing 2-methylpyridine organic cobalt catalyst comprises the following steps:
example 1
1. And (4) synthesizing. 89g of cobalt chloride hexahydrate, 40g of sodium carbonate and 33g of cyclopentadiene are placed in a 1000mL reaction bottle, 500mL of N, N-dimethylformamide solution is added, the mixture is stirred and dissolved, the temperature is set to be 90 ℃, and the reaction is refluxed for 10 hours.
2. And (6) processing. The resulting reaction solution was cooled, distilled under reduced pressure at 80 ℃ to distill off the solvent N, N-dimethylformamide to give a pink solid, and extracted with 200mL of water and 200mL of dichloromethane to discharge the aqueous solution. Repeating the operation for three times, adding sodium sulfate aqueous solution for extraction once, and discharging the aqueous solution. The obtained dichloromethane solution containing the organic cobalt catalyst is put at the temperature of minus 5 ℃ for crystallization, and after being refrigerated for 8 hours, the reaction solution is taken out, and solid is precipitated. And carrying out suction filtration to obtain the organic cobalt catalyst crystal. The crystals were dried at 50 ℃ and 40g were weighed, giving a yield of 83%.
Example 2:
1. and (4) synthesizing. 107g of cobalt chloride hexahydrate, 48g of sodium carbonate and 33g of cyclopentadiene were placed in a 1000mL reaction flask, 800mL of N, N-dimethylformamide solution was added, dissolved by stirring, the temperature was set at 93 ℃, and the reaction was refluxed for 8 hours.
2. And (6) processing. The resulting reaction solution was cooled, distilled under reduced pressure at 80 ℃ to distill off the solvent N, N-dimethylformamide to give a pink solid, and extracted with 200mL of water and 200mL of dichloromethane to discharge the aqueous solution. Repeating the operation for three times, adding sodium sulfate aqueous solution for extraction once, and discharging the aqueous solution. The obtained dichloromethane solution containing the organic cobalt catalyst is put at the temperature of minus 5 ℃ for crystallization, and after being refrigerated for 8 hours, the reaction solution is taken out, and solid is precipitated. And carrying out suction filtration to obtain the organic cobalt catalyst crystal. The crystals were dried at 50 ℃ and 42g were weighed, giving a yield of 86%.
Example 3:
1. and (4) synthesizing. 109g of cobalt chloride hexahydrate, 49g of sodium carbonate and 50g of cyclopentadiene are placed in a 1000mL reaction bottle, 700mL of N, N-dimethylformamide solution is added, the mixture is stirred and dissolved, the temperature is set to be 95 ℃, and the reaction is refluxed for 10 hours.
2. And (6) processing. The resulting reaction solution was cooled, distilled under reduced pressure at 80 ℃ to distill off the solvent N, N-dimethylformamide to give a pink solid, and extracted with 200mL of water and 200mL of dichloromethane to discharge the aqueous solution. Repeating the operation for three times, adding sodium sulfate aqueous solution for extraction once, and discharging the aqueous solution. The obtained dichloromethane solution containing the organic cobalt catalyst is put at the temperature of minus 5 ℃ for crystallization, and after being refrigerated for 8 hours, the reaction solution is taken out, and solid is precipitated. And carrying out suction filtration to obtain the organic cobalt catalyst crystal. The crystals were dried at 50 ℃ and 57g were weighed, giving a yield of 78%.
Example 4:
1. and (4) synthesizing. 109g of cobalt chloride hexahydrate, 49g of sodium carbonate and 50g of cyclopentadiene are placed in a 1000mL reaction bottle, 700mL of N, N-dimethylformamide solution is added, the mixture is stirred and dissolved, the temperature is set to be 90 ℃, and the reaction is refluxed for 10 hours.
2. And (6) processing. The resulting reaction solution was cooled, distilled under reduced pressure at 80 ℃ to distill off the solvent N, N-dimethylformamide to give a pink solid, and extracted with 200mL of water and 200mL of dichloromethane to discharge the aqueous solution. Repeating the operation for three times, adding sodium sulfate aqueous solution for extraction once, and discharging the aqueous solution. The obtained dichloromethane solution containing the organic cobalt catalyst is put at the temperature of minus 5 ℃ for crystallization, and after being refrigerated for 8 hours, the reaction solution is taken out, and solid is precipitated. And carrying out suction filtration to obtain the organic cobalt catalyst crystal. The crystals were dried at 50 ℃ and 59g were weighed, giving a yield of 81%.
In the above 4 embodiments, cobalt chloride hexahydrate, cyclopentadiene, sodium carbonate, N-dimethylformamide and dichloromethane are used as raw materials, a one-step synthesis reaction is adopted, synthesis steps are reduced, a low-temperature crystallization mode is adopted, the purity of the catalyst is improved, metal salts such as sodium chloride are removed in an extraction mode, the residual metal salts are less, the influence of the metal salts on the structure of the synthesized catalyst is reduced, dichloromethane is used as a crystallization solvent, the boiling point of dichloromethane is low, the solubility is high, the loss of the catalyst can be reduced due to the fact that dichloromethane is not mutually soluble with water, the weight of the obtained organic cobalt catalyst can reach more than 40g, and the yield can reach more than 78%.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be able to cover the technical solutions and the inventive concepts of the present invention within the technical scope of the present invention.
Claims (7)
1. A method for synthesizing a 2-methylpyridine organic cobalt catalyst is characterized by comprising the following steps:
step 1: selecting sodium carbonate as alkali, placing cobalt chloride, cyclopentadiene and sodium carbonate in N, N-dimethylformamide for high-temperature reaction, and coordinating cyclopentadiene with cobalt chloride under alkaline condition to generate an organic cobalt catalyst;
step 2: dissolving the generated organic cobalt catalyst in N, N-dimethylformamide, evaporating the N, N-dimethylformamide through reduced pressure distillation, adding water and dichloromethane, dissolving sodium chloride in the water, separating after layering, reducing the salt content in the organic solvent through repeated extraction operation, putting the obtained dichloromethane solution into a low-temperature environment, slowly separating out the organic cobalt catalyst, separating out crystals, and obtaining the high-purity organic cobalt catalyst through suction filtration and drying.
2. The method for synthesizing 2-methylpyridine organocobalt catalyst according to claim 1, characterized in that the synthesis reaction of step 1 is carried out under alkaline conditions, using sodium carbonate as base, with a molar ratio of sodium carbonate to cyclopentadiene, cobalt chloride hexahydrate between 1.2:2:1.2 and 1.8:2: 1.8.
3. The method for synthesizing the 2-methylpyridine organocobalt catalyst according to claim 1, wherein the N, N-dimethylformamide in the step 1 is used as a synthesis reaction solvent, and the mass ratio of the solvent to the cobalt chloride is 5.4-8.5.
4. The method for synthesizing the 2-methylpyridine organocobalt catalyst according to claim 1, wherein the synthesis reaction temperature in the step 1 is 90-100 ℃ and the reaction time is 8-10 h.
5. The method for synthesizing the 2-methylpyridine organic cobalt catalyst according to claim 1, wherein the treatment after the reaction in step 2 adopts dichloromethane and water to dissolve and extract for 2-3 times, and sodium sulfate aqueous solution is added to extract impurities in the organic phase, wherein the concentration of the sodium sulfate solution is 21.9-25%.
6. The method for synthesizing the 2-methylpyridine organic cobalt catalyst according to claim 1, wherein in the post-reaction treatment in the step 2, the dichloromethane solution obtained by extraction is placed in an environment with a low temperature of-5 to 0 ℃ for cooling and crystallization, and the crystallization time is 7 to 8 hours.
7. The method for synthesizing the 2-methylpyridine organic cobalt catalyst according to claim 1, wherein the solution after crystallization in the reaction post-treatment of the step 2 is subjected to low-temperature suction filtration, and the drying temperature of the suction filtration solid is 50-60 ℃.
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2020
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