CN111777558B - Production process of 1, 3-dimethyl-4-chloromethylpyrazole-5-formate - Google Patents
Production process of 1, 3-dimethyl-4-chloromethylpyrazole-5-formate Download PDFInfo
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- CN111777558B CN111777558B CN202010695278.0A CN202010695278A CN111777558B CN 111777558 B CN111777558 B CN 111777558B CN 202010695278 A CN202010695278 A CN 202010695278A CN 111777558 B CN111777558 B CN 111777558B
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D231/00—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings
- C07D231/02—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings
- C07D231/10—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members
- C07D231/14—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
Abstract
The invention provides a production process of 1, 3-dimethyl-4-chloromethylpyrazole-5-formate, wherein the formaldehyde raw material is paraformaldehyde with the following dosage: 1.05-1.50 equivalents; the solvent is a low-polarity high-boiling-point hydrophobic solvent, and the reaction temperature is 70-140 ℃; the post-treatment scheme adopted by the process is that water is added for washing, and then decompression desolventizing is carried out. The invention reduces the dosage of paraformaldehyde while improving the reaction speed, effectively simplifies the post-treatment process, avoids the operation of washing formaldehyde with water and obviously reduces the amount of three wastes generated by reaction.
Description
Technical Field
The invention relates to a chloromethylation reaction technology in the field of agricultural chemical industry.
Background
1, 3-dimethyl-4-chloromethylpyrazole-5-formate is an important heterocyclic intermediate and is widely applied to pesticides and medicines. For example, the 1,3, 4-trimethylpyrazole-5-formate intermediate obtained after the compound is subjected to hydrogenation and dechlorination is an important raw material for synthesizing the novel acaricide tebufenpyrad.
The synthetic route of the compound is mainly that 1, 3-dimethylpyrazole-5-formate is taken as a raw material and is prepared through Blanc chloromethylation reaction (the brandy chloromethylation reaction is the reaction of aromatic compound, formaldehyde and hydrogen chloride under the action of anhydrous zinc chloride to generate chloromethyl aromatic compound), such as patent JP2001342178A, CN106608872, CN108570008 and CN107216288; paper fine chemical intermediate 2014,44 (6): 117-19.
Almost all reports use dioxane as a solvent, the dosage of paraformaldehyde is 2 molar equivalents, the dioxane is recovered firstly in the post-reaction treatment process, then the crude product is poured into ice water, and the crude product is further extracted and washed by an organic solvent and further concentrated to obtain the crude product. From the whole process, the steps of washing, extracting and the like are carried out after the dioxane is recovered by post-treatment, and the main purposes are to wash out excessive paraformaldehyde, so that the post-treatment is complex and more three wastes are generated; in addition, the compound is poorly soluble in most solvents, as analyzed by the physicochemical properties of paraformaldehyde, and thus is more difficult to remove by water washing; another notable problem is that paraformaldehyde is susceptible to sublimation when heated, and excessive paraformaldehyde gradually blocks the pipeline during desolventizing, with potential pipe blocking risks in large scale production. Therefore, finding a new process which can remarkably reduce the dosage of paraformaldehyde and simplify the post-reaction treatment step to replace the current chloromethylation process has great significance.
Disclosure of Invention
The invention aims to: provides a process for preparing 1, 3-dialkyl pyrazole-5-formate by chloromethylation, which obviously reduces the dosage of paraformaldehyde, reduces the generation of three wastes and quickens the reaction speed.
The technical scheme is as follows: in the traditional production process, the reason that the dosage of the paraformaldehyde is doubled (the actual molar number is about twice that of the reactive molar number) is caused by the lower boiling point of a solvent adopted in the reaction, lower reaction temperature and low reaction activity.
In order to achieve the above object, the present technology has been reported to be adjusted in terms of solvent type, paraformaldehyde feeding system, reaction temperature, post-treatment system, and the like, as compared with the prior art.
The inventor of the application finds through a comparison experiment that the solvent with high boiling point is selected, and meanwhile, the reaction temperature is improved, so that the reaction rate is accelerated, and the dosage of paraformaldehyde is obviously reduced;
the weak polar hydrophobic solvent with high boiling point is further selected, so that the solubility of hydrogen chloride can be ensured, water generated in the reaction can be directly separated through water separation operation after the reaction is completed, water-soluble impurities are removed, and the reaction solution after water separation is desolventized, so that the 1, 3-dialkyl-4-chloromethylpyrazole-5-formate with high content can be obtained.
The process is an optional low-polarity high-boiling point hydrophobic solvent: comprises chlorobenzene, dichlorobenzene, 1, 2-dichloropropane, 1, 3-dichloropropane, 1, 2-trichloroethane, 1,2, 3-trichloropropane (trichloroethane and trichloropropane have the same number of chlorine atoms or chloride ions as trioxymethylene and aluminum trichloride, are compatible, the mol number of each substance is easy to control accurately, the dissolution point is-14.7, the boiling point of trichloroethane is about 75 ℃, the boiling point of trichloropropane is 156.8 ℃, the natural point is 304.4, the trichloropropane is a chemical reagent commonly used in industry, colorless flammable liquid, slightly soluble in water and has the specific gravity of 1.39g/ml, can be layered with miscible water, and can dissolve solvents such as oil, grease, wax, chlorinated rubber and most resins), n-pentane, chlorocyclopentane, chloron-hexane, chlorocyclohexane, cyclopentylmethyl ether, toluene, xylene, tertiary butanol, n-butyl ether and the like.
The formaldehyde raw materials selected by the process can be as follows: the scheme for mixing paraformaldehyde or paraformaldehyde with the catalyst Lewis acid is as follows: paraformaldehyde+sulfuric acid; paraformaldehyde + phosphoric acid; paraformaldehyde + calcium chloride; paraformaldehyde + chlorosulfonic acid; paraformaldehyde + thionyl chloride; paraformaldehyde + magnesium chloride; paraformaldehyde + zinc chloride; trioxymethylene + phosphorus oxychloride is preferred.
The relative density 2.907 of trioxymethylene and zinc chloride is preferable, the melting point is about 290 ℃, the boiling point is 732 ℃, the relative density is far higher than phosphorus oxychloride (the boiling point is 105.8 ℃) and aluminum trichloride (the boiling point is lower than the melting point of 194 ℃), and when the temperature of a reaction system is higher, the stability of the catalyst is not affected, so that the catalytic reaction is smoothly carried out.
The dosage of the paraformaldehyde adopted in the process is as follows: 1.05 to 1.50 equivalents. Preferably 1.25 equivalents. The addition amount of the selected Lewis acid catalyst is as follows: 1% -10% equivalent. Preferably 5%.
The material feeding mode adopted by the process is as follows: adding paraformaldehyde into the reaction system at one time or in multiple times; preferably, paraformaldehyde is prepared into suspension liquid to be added into the reaction system in a dripping way. The paraformaldehyde is better dispersed, and the contact with the 1, 3-dimethylpyrazole-5-formate raw material is more beneficial and uniform.
The reaction temperature adopted by the process is as follows: the reaction temperature is higher at 70-140 ℃, preferably 110-120 ℃, the reaction activity is higher, the reaction rate is faster, and the required formaldehyde raw material is less in surplus.
The post-treatment scheme adopted by the process is as follows: washing with water, and removing solvent under reduced pressure; preferably, the post-treatment scheme is that water is separated after water is added for washing, and then the pressure is reduced for desolventizing. The solvent has no water basically during desolventizing, and can be directly reused or used for other purposes.
The invention has the following advantages:
1. the reaction speed is improved, the dosage of paraformaldehyde is obviously reduced, and the raw material cost is reduced.
2. The post-treatment process is effectively simplified, the operation of washing formaldehyde with water is avoided, and the solvent is not required to be recovered by decompression twice.
3. The process is simplified, the amount of three wastes generated by the reaction is obviously reduced, and the method is environment-friendly.
4. The hydrophobic solvent used in the reaction does not need to be dried independently, and the water content of the solvent does not increase greatly with the increase of the application times.
5. The problems of sublimation pipe blockage and the like are effectively solved after the dosage of paraformaldehyde is reduced, and the industrialized application prospect is wider.
Detailed Description
The following examples serve to further illustrate the invention but the invention is by no means limited to these examples and various modifications are possible in accordance with the scope defined by the claims.
Example 1: A0.5L four-necked flask was taken, followed by adding 42.97g (0.25 mol) of 98% ethyl 1, 3-dimethylpyrazole-5-carboxylate and 252.11g of chlorocyclohexane thereto, stirring and heating to 110℃and then pumping hydrogen chloride gas into the system, followed by dropwise addition of 11.60g (0.375 mol, diluted with 42.5g of chlorocyclohexane) of 95% paraformaldehyde and 2.04g of phosphorus oxychloride suspension into the system. After the dripping is finished, maintaining the aeration speed of hydrogen chloride to be 0.1L/min, preserving the temperature at 120 ℃ for 5-6 h, and stopping the reaction after the peak area of the raw material is less than 0.5%. Cooling to room temperature, standing to separate out water phase, distilling the organic phase under reduced pressure to remove solvent, and finally obtaining 54.42g of light yellow to colorless crude 1, 3-dimethyl-4-chloromethylpyrazole-5-formate, wherein the crude is calibrated to have the content of 95.8% by GC, and the quantitative yield is 96.31%.
Example 2: A0.5L four-necked flask was taken, and a stirrer, a thermometer, an air duct and a condenser were used in combination, 98% of ethyl 1, 3-dimethylpyrazole-5-carboxylate (42.92 g) (0.25 mol 9) was added, then 168.92g of cyclopentyl methyl ether was added, stirring and heating were carried out until reflux, then hydrogen chloride gas was pumped into the system, and then a suspension of 95% paraformaldehyde (9.58 g (0.313 mol, diluted with 43.1g of cyclopentyl methyl ether) and 2.07g of aluminum trichloride were added dropwise into the system. After the dripping is finished, maintaining the ventilation speed of hydrogen chloride to be 0.1L/min, keeping the temperature and refluxing for 6-8 hours, and stopping the reaction after the peak area of the raw material is less than 0.5 percent. Cooling to room temperature, standing to separate out water phase, distilling the organic phase under reduced pressure to remove solvent, and finally obtaining 52.86g of light yellow to colorless crude 1, 3-dimethyl-4-chloromethylpyrazole-5-formate, wherein the crude has a GC external calibration content of 93.58% and a quantitative yield of 91.61%.
Example 3: A0.5L four-port bottle is taken, and is matched with a stirrer, a thermometer, an air duct and a condenser, 42.92g (0.25 mol) of 98%1, 3-dimethylpyrazole-5-ethyl formate is added, then 295.62g of chlorobenzene is added, stirring and heating are carried out until reflux, then hydrogen chloride gas is pumped into the system, and then 8.65g (0.275 mol, diluted by 44.64g of chlorobenzene) of 95% paraformaldehyde and 1.90g of sulfuric acid suspension are dropwise added into the system. After the dripping is finished, maintaining the ventilation speed of hydrogen chloride at 0.1L/min, keeping the temperature and refluxing for 5-6 hours, and stopping the reaction after the peak area of the raw material is less than 0.5%. Cooling to room temperature, standing to separate out water phase, distilling the organic phase under reduced pressure to remove solvent, and finally obtaining 54.33g of light yellow to colorless crude 1, 3-dimethyl-4-chloromethylpyrazole-5-formate, wherein the crude is calibrated to have the content of 91.44% by GC, and the quantitative yield is 92.00%.
Example 4: A0.5L four-port bottle is taken, a stirrer, a thermometer, an air duct and a condenser are matched, and then 42.95g (0.25 mol) of 98%1, 3-dimethylpyrazole-5-ethyl formate is added, then 253.61g of 1, 3-dichloropropane is added, stirring and heating are carried out until reflux, then hydrogen chloride gas is pumped into the system, and then 9.27g (0.30 mol, diluted by 42.88g of 1, 3-dichloropropane) of 95% paraformaldehyde and 2.10g of suspension of anhydrous zinc chloride are dropwise added into the system. After the dripping is finished, maintaining the ventilation speed of hydrogen chloride at 0.1L/min, keeping the temperature and refluxing for 5-6 hours, and stopping the reaction after the peak area of the raw material is less than 0.5%. Cooling to room temperature, standing to separate out water phase, distilling the organic phase under reduced pressure to remove solvent, and finally obtaining 52.83g of light yellow to colorless crude 1, 3-dimethyl-4-chloromethylpyrazole-5-formate, wherein the crude is calibrated to have 94.9% of external GC content and 92.84% of quantitative yield.
Example 5: A0.5L four-necked flask was taken, followed by addition of 98% of ethyl 1, 3-dimethylpyrazole-5-carboxylate (42.89, g) (0.25 mol) and then 215.44g of 1,2, 3-trichloropropane, stirring and heating to 130℃were carried out, then hydrogen chloride gas was pumped into the system, and then a suspension of 8.61g of 95% paraformaldehyde (0.275 mol, diluted with 42.38g of 1,2, 3-trichloropropane) and 2.10g of chlorosulfonic acid was dropwise added into the system. After the dripping is finished, maintaining the ventilation speed of hydrogen chloride to be 0.1L/min, preserving the heat for 4-5 hours, and stopping the reaction after the peak area of the raw material is less than 0.5 percent. Cooling to room temperature, standing to separate out water phase, distilling the organic phase under reduced pressure to remove solvent, and finally obtaining 53.03g of light yellow to colorless crude 1, 3-dimethyl-4-chloromethylpyrazole-5-formate, wherein the crude is subjected to GC external calibration, the content of the crude is 91.36%, and the quantitative yield is 89.44%.
Example 6: A0.5L four-necked flask was taken, and a stirrer, a thermometer, an air duct and a condenser were used, and 42.91g (0.25 mol) of 98% ethyl 1, 3-dimethylpyrazole-5-carboxylate was added, then 298.83g of 1, 2-trichloroethane was added, the mixture was stirred and heated to reflux, then a hydrogen chloride gas was pumped into the system, and then 10.73g (0.35 mol, diluted with 43.83g of 1, 2-trichloroethane) of 95% paraformaldehyde and 2.10g of phosphorus oxychloride were added dropwise into the system. After the dripping is finished, maintaining the ventilation speed of hydrogen chloride to be 0.1L/min, keeping the temperature and refluxing for 4-5 hours, and stopping the reaction after the peak area of the raw material is less than 0.5 percent. Cooling to room temperature, standing to separate out a water phase, and distilling the organic phase under reduced pressure to remove the solvent to obtain 53.18g of light yellow to colorless crude 1, 3-dimethyl-4-chloromethylpyrazole-5-formate, wherein the crude is calibrated to have 96.05% of external GC content and 94.59% of quantitative yield.
Example 7: A0.5L four-port bottle is taken, a stirrer, a thermometer, an air duct and a condenser are matched, and then 42.97g (0.25 mol) of 98%1, 3-dimethylpyrazole-5-ethyl formate is added, then 291.83g of 1, 2-dichloropropane is added, stirring and heating are carried out until reflux, then hydrogen chloride gas is pumped into the system, and then 11.66g (0.375 mol, diluted with 42.91g of 1, 2-dichloropropane) of 95% paraformaldehyde and 2.06g of suspension of anhydrous magnesium chloride are dropwise added into the system. After the dripping is finished, maintaining the ventilation speed of hydrogen chloride to be 0.1L/min, keeping the temperature and refluxing for 4-5 hours, and stopping the reaction after the peak area of the raw material is less than 0.5 percent. Cooling to room temperature, adding 50g of water for washing, standing to separate out a water phase, and distilling an organic phase under reduced pressure to remove a solvent to obtain 52.67g of light yellow to colorless crude 1, 3-dimethyl-4-chloromethylpyrazole-5-formate, wherein the crude is calibrated to have a content of 95.93% by GC, and the quantitative yield is 93.54%.
Example 8: A0.5L four-necked flask was taken, and a stirrer, a thermometer, an air-guide tube and a condenser were used, followed by adding 42.94g (0.25 mol) of 98% ethyl 1, 3-dimethylpyrazole-5-carboxylate and then adding 247.00g of n-butyl ether, stirring and heating to reflux, then pumping hydrogen chloride gas into the system, and then dropping 9.29g (0.30 mol, diluted with 42.88g of 1, 2-dichloropropane) of 95% paraformaldehyde and 2.06g of a suspension of anhydrous calcium chloride into the system. After the dripping is finished, maintaining the ventilation speed of hydrogen chloride to be 0.1L/min, keeping the temperature and refluxing for 4-5 hours, and stopping the reaction after the peak area of the raw material is less than 0.5 percent. Cooling to room temperature, adding 50g of water for washing, standing to separate out a water phase, and distilling an organic phase under reduced pressure to remove a solvent to obtain 52.81g of light yellow to colorless crude 1, 3-dimethyl-4-chloromethylpyrazole-5-formate, wherein the crude is calibrated to have 94.50% of external GC content and 92.42% of quantitative yield.
Control experiment 1: taking a 0.5L four-mouth bottle, matching with a stirrer, a thermometer, an air duct and a condenser tube, adding 42.96g (0.25 mol) of 98%1, 3-dimethylpyrazole-5-ethyl formate, then adding 250.10g of dioxane, then dropwise adding 2g of 98% concentrated sulfuric acid under stirring, then adding 15.47g of paraformaldehyde (0.50 mol), stirring and heating to reflux, pumping hydrogen chloride gas into the system, keeping the ventilation speed at 0.1L/min, keeping the temperature and refluxing for 5-6 h, and stopping the reaction after the peak area of the raw material is less than 0.5%. Then, the solvent dioxane was removed by distillation under reduced pressure, 200g of ice water was added to the obtained crude product, followed by extraction with 150g of toluene, and the organic phase after standing for phase separation was washed with 50g of ice water. The finally obtained organic phase is decompressed and desolventized to obtain 52.07g of light yellow to colorless crude product, the external calibration content of the crude product by GC is 93.09%, and the quantitative yield is 90.11%.
Control experiment 2: taking a 0.5L four-mouth bottle, matching with a stirrer, a thermometer, an air duct and a condenser tube, adding 42.96g (0.25 mol) of 98%1, 3-dimethylpyrazole-5-ethyl formate, then adding 250.10g of dioxane, then dropwise adding 2g of 98% concentrated sulfuric acid under stirring, then adding 11.61g of paraformaldehyde (0.375 mol), stirring and heating to reflux, pumping hydrogen chloride gas into the system, keeping the ventilation speed at 0.1L/min, keeping the temperature and refluxing for 5-6 h, and stopping the reaction after the peak area of the raw material is less than 0.5%. Then, the solvent dioxane was removed by distillation under reduced pressure, 200g of ice water was added to the obtained crude product, followed by extraction with 150g of toluene, and the organic phase after standing for phase separation was washed with 50g of ice water. The finally obtained organic phase is decompressed and desolventized to obtain 52.07g of light yellow to colorless crude product, the external calibration content of the crude product by GC is 88.16 percent, and the quantitative yield is 81.34 percent.
Claims (1)
1. A production process of 1, 3-dimethyl-4-chloromethylpyrazole-5-formate is characterized in that: the method comprises the following steps: taking a 0.5L four-mouth bottle, matching with a stirrer, a thermometer, an air duct and a condenser tube, adding 42.97g of 98%1, 3-dimethylpyrazole-5-ethyl formate with the molar weight of 0.25mol, then adding 252.11g of chlorocyclohexane, stirring and heating to 110 ℃, then pumping hydrogen chloride gas into the system, then dropwise adding 11.60g of 95% paraformaldehyde with the molar weight of 0.375mol, diluting with 42.5g of chlorocyclohexane, and 2.04g of phosphorus oxychloride suspension; maintaining the aeration speed of hydrogen chloride at 0.1L/min after the dripping, preserving the temperature at 120 ℃ for 5-6 h, and stopping the reaction after the peak area of the raw material is less than 0.5%; cooling to room temperature, standing to separate out water phase, distilling the organic phase under reduced pressure to remove solvent, and finally obtaining 54.42g of light yellow to colorless crude 1, 3-dimethyl-4-chloromethylpyrazole-5-formate, wherein the crude is calibrated to have the content of 95.8% by GC, and the quantitative yield is 96.31%.
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| EP0658547A1 (en) * | 1993-12-14 | 1995-06-21 | Mitsubishi Chemical Corporation | N-pyrazolyl carbamate derivative, agricultural/horticultural fungicide containing the same as active ingredient and production intermediate thereof |
| JPH115972A (en) * | 1997-06-17 | 1999-01-12 | Mitsubishi Chem Corp | Photochromic material |
| JP2001342178A (en) * | 2000-06-05 | 2001-12-11 | Nissan Chem Ind Ltd | Method for producing 4-methylpyrazole-5-carboxylic acid |
| JP2008007503A (en) * | 2006-06-01 | 2008-01-17 | Nissan Chem Ind Ltd | Method for producing 4-methylpyrazole-5-carboxylic ester |
| CN106608873A (en) * | 2015-10-26 | 2017-05-03 | 湖南化工研究院有限公司 | Pyrazole amide compound, and preparation method and application thereof |
| CN107216288A (en) * | 2016-03-22 | 2017-09-29 | 湖南大学 | A kind of preparation method of Tolfenpyrad impurity |
| CN108570008A (en) * | 2017-03-14 | 2018-09-25 | 浙江省化工研究院有限公司 | Pyrazole analog derivative, preparation method and application |
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2020
- 2020-07-19 CN CN202010695278.0A patent/CN111777558B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0658547A1 (en) * | 1993-12-14 | 1995-06-21 | Mitsubishi Chemical Corporation | N-pyrazolyl carbamate derivative, agricultural/horticultural fungicide containing the same as active ingredient and production intermediate thereof |
| JPH115972A (en) * | 1997-06-17 | 1999-01-12 | Mitsubishi Chem Corp | Photochromic material |
| JP2001342178A (en) * | 2000-06-05 | 2001-12-11 | Nissan Chem Ind Ltd | Method for producing 4-methylpyrazole-5-carboxylic acid |
| JP2008007503A (en) * | 2006-06-01 | 2008-01-17 | Nissan Chem Ind Ltd | Method for producing 4-methylpyrazole-5-carboxylic ester |
| CN106608873A (en) * | 2015-10-26 | 2017-05-03 | 湖南化工研究院有限公司 | Pyrazole amide compound, and preparation method and application thereof |
| CN107216288A (en) * | 2016-03-22 | 2017-09-29 | 湖南大学 | A kind of preparation method of Tolfenpyrad impurity |
| CN108570008A (en) * | 2017-03-14 | 2018-09-25 | 浙江省化工研究院有限公司 | Pyrazole analog derivative, preparation method and application |
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