Method for preparing triketone herbicide
阅读说明：本技术 一种制备三酮类除草剂的方法 (Method for preparing triketone herbicide ) 是由 于海波 吴长春 吴鸿飞 徐利保 郭春晓 徐靖博 程学明 董燕 孙宁宁 于 2020-06-28 设计创作，主要内容包括：本发明属于有机合成领域,具体涉及一种制备三酮类除草剂的方法。以取代苯甲酸为原料经酰氯化、酯化反应后获得酰化反应体系,再经重排反应制得三酮类除草剂,其特征在于：所述重排反应是在酰化反应体系中加入重排催化剂,于0℃-50℃,保温反应0.5-12小时,即得三酮类除草剂；本发明方法避免了使用剧毒的丙酮氰醇催化剂,反应温度较低,反应时间短,溶剂可循环套用,制备三酮类除草剂产品的总收率可达90％,含量为98％,且此工艺安全环保,三废量小,宜于工业化生产。(The invention belongs to the field of organic synthesis, and particularly relates to a method for preparing triketone herbicides. Substituted benzoic acid is taken as a raw material, an acylation reaction system is obtained after acyl chlorination and esterification reaction, and the triketone herbicide is prepared through rearrangement reaction, and the method is characterized in that: the rearrangement reaction is to add a rearrangement catalyst into an acylation reaction system, and carry out heat preservation reaction for 0.5 to 12 hours at the temperature of between 0 and 50 ℃ to obtain the triketone herbicide; the method avoids using a virulent acetone cyanohydrin catalyst, has lower reaction temperature, short reaction time and recyclable solvent, ensures that the total yield of the triketone herbicide product can reach 90 percent and the content is 98 percent, has safe and environment-friendly process and small three wastes, and is suitable for industrial production.)
1. A method for preparing triketone herbicide, using substituted benzoic acid as raw material, obtaining acylation reaction system after acyl chlorination and esterification reaction, then obtaining triketone herbicide through rearrangement reaction, characterized in that: the rearrangement reaction is that a rearrangement catalyst (formula III) is added into an acylation reaction system, and the reaction is carried out for 0.5 to 12 hours at the temperature of between 0 and 50 ℃ to obtain the triketone herbicide;
the molar ratio of the rearrangement catalyst (formula III) to the raw material is (0.0005-1): 1; wherein, the structure of the formula III is as follows,
wherein G is selected from C1-C6Alkyl radical, C1-C6Haloalkyl, C3-C6Cycloalkyl, phenyl and pyridyl, unsubstituted or optionally substituted by halogen, cyano, nitro, C1-C6Alkyl, halo C1-C6Alkyl radical, C3-C6Cycloalkyl radical, C1-C6Alkoxy, halo C1-C6Alkoxy radical, C1-C6Alkoxymethylene, halo C1-C6Alkoxymethylene, tetrahydrofuryl C1-C6Alkoxymethylene group, C1-C6Alkylthio, halo C1-C6Alkylthio radical, C1-C6Alkylamino radical, C1-C6Dialkylamino radical, C3-C6Cycloalkylamino, C1-C6Alkylsulfonyl or C1-C6An alkylaminosulfonyl group.
2. A process for the preparation of triketone herbicides according to claim 1 wherein: the reaction temperature of the acylation reaction system is 10-40 ℃, and the reaction is carried out for 0.5-10 hours.
3. A process for the preparation of triketone herbicides according to claim 2 wherein: the rearrangement reaction temperature is 20-40 ℃, and the reaction time is 0.5-8 hours; wherein, the molar ratio of the rearrangement catalyst (formula III) to the raw material is (0.001-1): 1.
4. A process for the preparation of triketone herbicides according to claim 3 wherein: the rearrangement reaction temperature is 25-35 ℃, and the reaction time is 0.5-6 hours; wherein the molar ratio of the rearrangement catalyst (formula III) to the raw material is (0.005-1): 1.
5. A process for the preparation of triketones according to any one of claims 1 to 4, characterized in that: adjusting the temperature of the acylation reaction system to room temperature, adding a rearrangement catalyst, reacting at the rearrangement temperature, adjusting the pH value of the system to be alkaline after the reaction, cooling to room temperature, standing, extracting and layering, collecting a water phase, adjusting the pH value of the water phase feed liquid to 1-2, filtering and washing to obtain the triketone herbicide.
6. A process for the preparation of triketones according to any one of claims 1 to 4, characterized in that: in the rearrangement catalyst (formula III), G is selected from C1-C3Alkyl radical, C1-C3Haloalkyl, cyclopropanealkyl, phenyl and pyridyl which are unsubstituted or optionally substituted by fluorine, chlorine, bromine, cyano, nitro, C1-C3Alkyl, halo C1-C3Alkyl, cyclopropane, C1-C3Alkoxy, halo C1-C3Alkoxy radical, C1-C3Alkoxymethylene, halo C1-C3Alkoxymethylene, tetrahydrofuryl C1-C3Alkoxymethylene group, C1-C3Alkylthio, halo C1-C3Alkylthio radical, C1-C3Alkylamino radical, C1-C3Dialkylamino, cyclopropylalkylamino, C1-C3Alkylsulfonyl or C1-C3An alkylaminosulfonyl group.
7. A process for the preparation of triketone herbicides according to claim 1 wherein: the acylation reaction system is characterized in that substituted benzoic acid is used as a raw material, a product brought by acyl chloride reaction is added into a solvent, 1, 3-cyclohexanedione is added, organic alkali is dropwise added at 0-10 ℃, and the reaction is continuously carried out for 0.5-1.5 hours under the condition of keeping the temperature after dropwise addition, so that the enol ester of the substituted benzoic acid as the acylation reaction product is obtained.
8. A process for the preparation of triketone herbicides according to claim 7 wherein: the solvent is toluene or 1, 2-dichloroethane; the organic base is trimethylamine, triethylamine, diisopropylethylamine, pyridine or 4-dimethylaminopyridine;
the molar ratio of a product obtained by using substituted benzoic acid as a raw material through an acyl chlorination reaction to a solvent to 1 (3-20) to (1-5) of 1, 3-cyclohexanedione to an organic base is 1.
9. The process for preparing triketone herbicides according to claim 1 or 7, wherein: adding raw material substituted benzoic acid into a solvent, heating to 50-55 ℃, dropwise adding thionyl chloride, continuing reflux reaction for 1.5-2.5 hours after dropwise adding, and decompressing and distilling out the solvent and excessive thionyl chloride to obtain the substituted benzoyl chloride shown in the general formula IV.
10. A process for the preparation of triketone herbicides according to claim 9 wherein: the molar ratio of the thionyl chloride to the raw material is (1-3) to 1.
Technical Field
The invention belongs to the field of organic synthesis, and particularly relates to a method for preparing triketone herbicides.
Background
The triketone herbicide is a high-efficiency, broad-spectrum and safe herbicide which is widely applied.
US 4921526 discloses a process for the translocation rearrangement of enol esters to acylated cyclic 1, 3-diketo herbicidal compounds, i.e. triketonic herbicidal compounds, catalyzed by acetone cyanohydrin.
WO 94045524, EP 666254, WO 9903845 and the like also disclose a process for the translocation rearrangement of enol esters to triketones under the action of an acetone cyanohydrin rearrangement catalyst.
Because acetone cyanohydrin belongs to highly toxic chemicals, the safety risk to people, livestock and environment is extremely high, and the research on safer rearrangement catalysts for preparing triketone herbicides is urgently needed.
Disclosure of Invention
The object of the present invention is to provide a process for the preparation of triketone herbicides.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a method for preparing triketone herbicide, using substituted benzoic acid (v) as raw materials, obtaining acylation reaction system after acyl chlorination and esterification reaction, and then obtaining triketone herbicide through rearrangement reaction, is characterized in that: the rearrangement reaction is that a rearrangement catalyst (formula III) is added into an acylation reaction system, and the reaction is carried out for 0.5 to 12 hours at the temperature of between 0 and 50 ℃ to obtain the triketone herbicide;
the molar ratio of the rearrangement catalyst (formula III) to the raw material is (0.0005-1): 1; wherein, the structure of the formula III is as follows,
wherein G is selected from C1-C6Alkyl radical, C1-C6Haloalkyl, C3-C6Cycloalkyl, phenyl and pyridyl, unsubstituted or optionally substituted by halogen, cyano, nitro, C1-C6Alkyl, halo C1-C6Alkyl radical, C3-C6Cycloalkyl radical, C1-C6Alkoxy, halo C1-C6Alkoxy radical, C1-C6Alkoxymethylene, halo C1-C6Alkoxymethylene, tetrahydrofuryl C1-C6Alkoxymethylene group, C1-C6Alkylthio, halo C1-C6Alkylthio radical, C1-C6Alkylamino radical, C1-C6Dialkylamino radical, C3-C6Cycloalkylamino, C1-C6Alkylsulfonyl or C1-C6An alkylaminosulfonyl group.
Preferably, in the rearrangement catalyst (formula III), G is selected from G and C1-C3Alkyl radical, C1-C3Haloalkyl, cyclopropanealkyl, phenyl and pyridyl which are unsubstituted or optionally substituted by the following groupsThe group is fluorine, chlorine, bromine, cyano, nitro, C1-C3Alkyl, halo C1-C3Alkyl, cyclopropane, C1-C3Alkoxy, halo C1-C3Alkoxy radical, C1-C3Alkoxymethylene, halo C1-C3Alkoxymethylene, tetrahydrofuryl C1-C3Alkoxymethylene group, C1-C3Alkylthio, halo C1-C3Alkylthio radical, C1-C3Alkylamino radical, C1-C3Dialkylamino, cyclopropylalkylamino, C1-C3Alkylsulfonyl or C1-C3An alkylaminosulfonyl group.
Preferably, in the rearrangement catalyst (formula III), G is selected from C1-C3Alkyl radical, C1-C3Haloalkyl, cyclopropyl, phenyl and pyridyl unsubstituted or optionally substituted by fluorine, chlorine, bromine, nitro, C1-C3Alkyl, halo C1-C3Alkyl radical, C1-C3Alkoxy, halo C1-C3Alkoxy radical, C1-C3Alkoxymethylene, halo C1-C3Alkoxymethylene, tetrahydrofuryl C1-C3Alkoxymethylene group, C1-C3An alkylsulfonyl group.
Further preferably, in the rearrangement catalyst (formula III), G is selected from the group consisting of methyl, chloromethyl, cyclopropane, phenyl and pyridyl which are unsubstituted or optionally substituted by fluorine, chlorine, bromine, nitro, methyl, trifluoromethyl, methoxy, trifluoromethoxy, ethoxymethylene, trifluoroethoxymethylene, tetrahydrofurylmethyleneoxymethylene, methylsulfonyl,
still more preferably, in the rearrangement catalyst (formula III), G is selected from the group consisting of methyl, chloromethyl, cyclopropane, phenyl, 3-pyridyl, 4-chlorophenyl, 2-methylphenyl, 3-methoxyphenyl, 4-trifluoromethoxyphenyl,
More preferably, in the rearrangement catalyst (formula III), G is selected from the group consisting of methyl, phenyl, 2-tolyl, N-acetyl, N-acetyl, N,
Most preferably, the rearrangement catalyst (formula III) wherein G is selected from phenyl, 2-tolyl.
Furthermore, the reaction temperature of the acylation reaction system is between 10 and 40 ℃, and the reaction is carried out for 0.5 to 10 hours.
The rearrangement reaction temperature is 20-40 ℃, and the reaction time is 0.5-8 hours; wherein, the molar ratio of the rearrangement catalyst (formula III) to the raw material is (0.001-1): 1.
The rearrangement reaction temperature is 25-35 ℃, and the reaction time is 0.5-6 hours; wherein the molar ratio of the rearrangement catalyst (formula III) to the raw material is (0.005-1): 1.
The rearrangement reaction temperature is 25-35 ℃, and the reaction time is 0.5-5 hours; wherein, the molar ratio of the rearrangement catalyst (formula III) to the raw material is (0.01-1): 1.
The rearrangement reaction temperature is 30-35 ℃, and the reaction time is 0.5-4 hours; wherein, the molar ratio of the rearrangement catalyst (formula III) to the raw material is (0.01-1): 1.
Adjusting the temperature of the acylation reaction system to room temperature, adding a rearrangement catalyst, reacting at the rearrangement temperature, adjusting the pH value of the system to be alkaline after the reaction, cooling the temperature, standing and layering the mixture at the room temperature, collecting the upper feed liquid, extracting the upper feed liquid, collecting the upper feed liquid, adjusting the pH value to be acidic, filtering and washing the mixture to obtain the triketone herbicide.
The acylation reaction system is characterized in that substituted benzoic acid (v) is used as a raw material, a product brought by acyl chloride reaction is added into a solvent, 1, 3-cyclohexanedione is added, organic alkali is dropwise added at 0-10 ℃, and the reaction is continued for 0.5-1.5 hours under heat preservation after the dropwise addition is finished, so that the enol ester of the substituted benzoic acid as the acylation reaction product is obtained.
Adding raw material substituted benzoic acid (v) into a solvent, heating to 50-55 ℃, dropwise adding thionyl chloride, continuing reflux reaction for 1.5-2.5 hours after dropwise adding, and evaporating the solvent and excessive thionyl chloride under reduced pressure to obtain the substituted benzoyl chloride with the general formula IV.
Further, the method for preparing the triketone herbicide has the following reaction formula,
1) acyl chloride reaction formula
2) Acylation reaction formula
3) Rearrangement reaction formula
In the reaction formula:
R1selected from chlorine, nitro, preferably nitro;
R2selected from hydrogen,Preferably hydrogen,More preferably hydrogen;
g is selected from the same groups as described above.
1) Acyl chlorination reaction
Dissolving the substituted benzoic acid shown in the general formula V in a solvent toluene or 1, 2-dichloroethane, heating to 50-55 ℃, dropwise adding thionyl chloride, continuing reflux reaction for 1.5-2.5 hours after dropwise adding, and evaporating the solvent and excessive thionyl chloride under reduced pressure to obtain the substituted benzoyl chloride shown in the general formula IV. The solvent is preferably 1, 2-dichloroethane.
2) Acylation reaction
Adding a solvent toluene or 1, 2-dichloroethane into the product obtained in the step 1), namely the substituted benzoyl chloride in the general formula IV, then adding 1, 3-cyclohexanedione, dropwise adding organic base trimethylamine, triethylamine, diisopropylethylamine, pyridine or 4-dimethylaminopyridine at 0-10 ℃, and continuing to react for 0.5-1.5 hours under heat preservation after dropwise adding to obtain a compound in the general formula II, namely the (3-oxocyclohex-1-en-1-yl) substituted benzoate. The solvent is preferably 1, 2-dichloroethane; the organic base is preferably selected from trimethylamine, triethylamine and diisopropylethylamine, and more preferably triethylamine.
3) Rearrangement reaction
Adding a rearrangement catalyst, namely a compound III in the general formula, into the reaction liquid after the acylation reaction in the step 2).
Wherein the molar ratio of thionyl chloride to substituted benzoic acid of the general formula V is (1-3) to 1, preferably (1-1.5): 1; the molar ratio of organic base to substituted benzoic acid of formula V is (1-5):1, preferably (1-3):1, more preferably (2-3): 1.
In the definitions of the compounds of the general formula given above, the terms used in the collection generally represent the following substituents:
halogen: refers to fluorine, chlorine, bromine or iodine.
Alkyl groups: straight-chain or branched alkyl radicals, such as the methyl, ethyl, n-propyl, isopropyl or the different butyl, pentyl or hexyl isomers.
Halogenated alkyl groups: straight-chain or branched alkyl groups, the hydrogen atoms on which may be partially or fully substituted by halogen, such as chloromethyl, dichloromethyl, trichloromethyl, fluoromethyl, difluoromethyl, trifluoromethyl, heptafluoroisopropyl, and the like.
Cycloalkyl groups: substituted or unsubstituted cyclic alkyl groups such as cyclopropyl, cyclopentyl or cyclohexyl; substituents such as methyl, halogen, and the like.
Unsubstituted means that all substituents are hydrogen.
Alkoxy groups: straight or branched chain alkyl groups attached to the structure via an oxygen atom, such as methoxy, ethoxy, t-butoxy, and the like.
Haloalkoxy groups: straight-chain or branched alkoxy groups, in which the hydrogen atoms may be partially or completely replaced by halogen, such as chloromethoxy, dichloromethoxy, trichloromethoxy, fluoromethoxy, difluoromethoxy, trifluoromethoxy, chlorofluoromethoxy, trifluoroethoxy and the like.
An alkoxymethylene group: alkyl-O-CH2-, e.g. CH3OCH2-。
Haloalkoxymethylene group: haloalkyl-O-CH2-, e.g. CF3CH2OCH2-。
Tetrahydrofurylalkoxymethylene group: tetrahydrofuryl-alkyl-O-CH2-, e.g.
Alkylthio group: straight or branched chain alkyl groups attached to the structure via a sulfur atom, such as methylthio, ethylthio, and the like.
Haloalkylthio: straight-chain or branched alkylthio groups in which the hydrogen atoms may be partially or fully substituted by halogen, such as difluoromethylthio, trifluoroethylthio, and the like.
Alkylamino group: straight or branched chain alkyl groups attached to the structure via a nitrogen atom, such as methylamino, ethylamino, n-propylamino, isopropylamino, or the isomeric butylamines.
Dialkylamino group: two identical or different linear or branched alkyl groups are attached to the structure via a nitrogen atom, such as dimethylamino, methylethylamino, and the like.
Cycloalkylamino group: cycloalkyl-NH-, such as cyclopropylamino.
An alkylsulfonyl group: alkyl-S (O)2-, for example methylsulfonyl.
Alkylaminosulfonyl: alkyl-NH-S (O)2-, e.g. CH3NH S(O)2-。
Compared with the prior art, the invention has the advantages that:
the transposition catalyst of the invention overcomes the risk brought by the highly toxic acetone cyanohydrin, and has mild reaction condition and high yield. The invention provides an effective preparation method for the industrialized production of the triketone herbicide.
Detailed Description
The following example results are provided to further illustrate the invention but are not meant to limit the invention.
The preparation of compound V substituted benzoic acid in each example was carried out as per the procedures described in references US4780127A and CN109678767, or as commercially available intermediates.
Example 1
1) Preparation of 4-methanesulfonyl-2-nitrobenzoyl chloride by acid chlorination:
4-methanesulfonyl-2-nitrobenzoic acid (14.9g, 0.06mol), DMF (0.2g) and 1, 2-dichloroethane (80g) were added to a dry reaction flask, stirred and heated to 50-55 deg.C, thionyl chloride (9.4g, 0.078mol) was added dropwise, after dropping, the reaction was carried out at reflux temperature for 2 hours, and the solvent and excess thionyl chloride were evaporated under reduced pressure to obtain 15.8g of 4-methanesulfonyl-2-nitrobenzoyl chloride.
2) Acylation reaction (3-oxocyclohex-1-en-1-yl) -4-methanesulfonyl-2-nitrobenzoate preparation:
1, 2-dichloroethane (160g) and 1, 3-cyclohexanedione (7.2g, 0.063mol) were added to the 4-methanesulfonyl-2-nitrobenzoyl chloride obtained above, triethylamine (18.4g, 0.18mol) was added dropwise at 2-10 ℃ for 1.5-2 hours, and the mixture was incubated at 5-10 ℃ for 0.5 hour to obtain intermediate (3-oxocyclohex-1-en-1-yl) -4-methanesulfonyl-2-nitrobenzoate.
3) Preparation of rearrangement reaction 2- (4-methanesulfonyl-2-nitrobenzoyl) -1, 3-cyclohexanedione (mesotrione):
the reaction solution is quickly heated to 25 ℃, a rearrangement transposition catalyst o-methylbenzonitrile (0.2g, 1.35mmol) is added, and the temperature is raised to 33-35 ℃ for reaction for 4 hours. Adding water (60g), dropwise adding 20% potassium hydroxide solution until the pH value is 10-11, stirring at room temperature for 0.5 hour, standing, layering, collecting the lower organic phase, adding 1, 2-dichloroethane into the upper layer of feed liquid for extraction once, combining the organic phases to recover the solvent and triethylamine, adding 10% hydrochloric acid into the upper layer of feed liquid for acidification until the pH value is 1-2, stirring at room temperature for 2 hours, filtering, washing the filter cake twice with water, discharging to obtain 20.6g of light yellow wet product, and drying at 40-50 ℃ to obtain 18.9g of mesotrione raw drug product with the quantitative content of 98.0% and the yield of 90.9% (calculated by 4-methylsulfonyl-2-nitrobenzoic acid).
Example 2
1) Preparation of 4-methanesulfonyl-2-nitrobenzoyl chloride by acid chlorination:
4-methanesulfonyl-2-nitrobenzoic acid (14.9g, 0.06mol), DMF (0.2g) and 1, 2-dichloroethane (80g) were added to a dry reaction flask, stirred and heated to 50-55 deg.C, thionyl chloride (14.5g, 0.12mol) was added dropwise, after dropping, the reaction was carried out at reflux temperature for 2 hours, and the solvent and excess thionyl chloride were evaporated under reduced pressure to give 15.9g of 4-methanesulfonyl-2-nitrobenzoyl chloride.
2) Acylation reaction (3-oxocyclohex-1-en-1-yl) -4-methanesulfonyl-2-nitrobenzoate preparation:
1, 2-dichloroethane (160g) and 1, 3-cyclohexanedione (7.2g, 0.063mol) were added to the 4-methanesulfonyl-2-nitrobenzoyl chloride obtained above, triethylamine (18.4g, 0.18mol) was added dropwise at 5-8 ℃ for 1.5-2 hours, and the mixture was incubated at 5-8 ℃ for 0.5 hour to obtain intermediate (3-oxocyclohex-1-en-1-yl) -4-methanesulfonyl-2-nitrobenzoate.
3) Preparation of rearrangement reaction 2- (4-methanesulfonyl-2-nitrobenzoyl) -1, 3-cyclohexanedione (mesotrione):
the reaction solution is quickly heated to 25 ℃, a rearrangement transposition catalyst benzoyl nitrile (0.2g, 1.5mmol) is added, and the temperature is raised to 30-33 ℃ for reaction for 3.5 hours. Adding water (60g), dropwise adding 20% potassium hydroxide solution until the pH value is 10-11, stirring at room temperature for 0.5 hour, standing, layering, collecting the lower organic phase, adding 1, 2-dichloroethane into the upper layer of feed liquid for extraction once, combining the organic phases to recover the solvent and triethylamine, adding 10% hydrochloric acid into the upper layer of feed liquid for acidification until the pH value is 1-2, stirring at room temperature for 2 hours, filtering, washing the filter cake twice with water, discharging to obtain 20.7g of light yellow wet product, and drying at 40-50 ℃ to obtain 18.8g of mesotrione raw drug product, wherein the quantitative content is 98.2%, and the yield is 90.6% (calculated on 4-methylsulfonyl-2-nitrobenzoic acid).
Example 3
1) Preparation of acyl chlorination reaction 2-chloro-4-methanesulfonylbenzoyl chloride:
adding 2-chloro-4-methylsulfonylbenzoic acid (14.4g, 0.06mol), DMF (0.2g) and 1, 2-dichloroethane (80g) into a dry reaction flask, stirring and heating to 50-55 ℃, dropwise adding thionyl chloride (9.4g, 0.078mol), reacting at reflux temperature for 2 hours after dropwise adding, and evaporating the solvent and the excessive thionyl chloride under reduced pressure to obtain 15.2g of 2-chloro-4-methylsulfonylbenzoyl chloride.
2) Preparation of acylation reaction (3-oxocyclohex-1-en-1-yl) -2-chloro-4-methanesulfonyl benzoate:
to the 2-chloro-4-methanesulfonylbenzoyl chloride obtained above were added 1, 2-dichloroethane (160g) and 1, 3-cyclohexanedione (7.2g, 0.063mol), triethylamine (18.4g, 0.18mol) was added dropwise at controlled temperature of 2 to 10 ℃ for 1.5 to 2 hours, and the mixture was incubated at 5 to 10 ℃ for 0.5 hour to obtain intermediate (3-oxocyclohex-1-en-1-yl) -2-chloro-4-methanesulfonylbenzoate.
3) Preparation of rearrangement reaction 2- (2-chloro-4-methanesulfonylbenzoyl) -1, 3-cyclohexanedione (sulcotrione):
the reaction solution is quickly heated to 25 ℃, a rearrangement transposition catalyst o-methylbenzonitrile (0.2g, 1.35mmol) is added, and the temperature is raised to 33-35 ℃ for reaction for 4 hours. Adding water (60g), dropwise adding 20% potassium hydroxide solution until the pH value is 10-11, stirring at room temperature for 0.5 hour, standing, layering, collecting the lower organic phase, adding 1, 2-dichloroethane into the upper layer of feed liquid for extraction once, combining the organic phase and triethylamine to be recovered, adding 10% hydrochloric acid into the upper layer of feed liquid for acidification until the pH value is 1-2, stirring at room temperature for 2 hours, filtering, washing the filter cake twice with water, discharging to obtain 20.2g of light yellow wet product, and drying at 40-50 ℃ to obtain 18.3g of sulcotrione raw drug product, wherein the quantitative content is 97.8%, and the yield is 90.7% (calculated on 2-chloro-4-methylsulfonylbenzoic acid).
Example 4
1) Preparation of acid chlorination reaction 2-chloro-4-methanesulfonyl-3- ((2,2, 2-trifluoroethoxy) methyl) benzoyl chloride:
2-chloro-4-methanesulfonyl-3- ((2,2, 2-trifluoroethoxy) methyl) benzoic acid (21.3g, 0.06mol), DMF (0.2g) and 1, 2-dichloroethane (80g) were added to a dry reaction flask, stirred and warmed to 50-55 ℃, thionyl chloride (9.4g, 0.078mol) was added dropwise, after completion of the addition, the reaction was carried out at reflux temperature for 2 hours, and the solvent and excess thionyl chloride were evaporated under reduced pressure to obtain 22.0g of 2-chloro-4-methanesulfonyl-3- ((2,2, 2-trifluoroethoxy) methyl) benzoyl chloride.
2) Preparation of acylation reaction (3-oxocyclohex-1-en-1-yl) -2-chloro-4-methanesulfonyl-3- ((2,2, 2-trifluoroethoxy) methyl) benzoate:
to the 2-chloro-4-methanesulfonyl-3- ((2,2, 2-trifluoroethoxy) methyl) benzoyl chloride obtained above was added 1, 2-dichloroethane (160g) and 1, 3-cyclohexanedione (7.2g, 0.063mol), triethylamine (18.4g, 0.18mol) was added dropwise at controlled temperature of 2 to 10 ℃ over 1.5 to 2 hours, and the mixture was incubated at 5 to 10 ℃ for 0.5 hour to obtain intermediate (3-oxocyclohex-1-en-1-yl) -2-chloro-4-methanesulfonyl-3- ((2,2, 2-trifluoroethoxy) methyl) benzoate.
3) Preparation of rearrangement reaction 2- (2-chloro-4-methanesulfonyl-3- ((2,2, 2-trifluoroethoxy) methyl) benzoyl) -1, 3-cyclohexanedione (tembotrione):
the reaction solution was rapidly warmed to 25 ℃ and o-methylbenzoyl nitrile (0.2g, 1.35mmol) was added and warmed to 33-35 ℃ for 4 hours. Adding water (60g), dropwise adding a 20% potassium hydroxide solution until the pH value is 10-11, stirring at room temperature for 0.5 hour, standing, layering, collecting the lower organic phase, adding 1, 2-dichloroethane into the upper layer of feed liquid for extraction once, combining the organic phase, a solvent to be recovered and triethylamine, adding 10% hydrochloric acid into the upper layer of feed liquid for acidification until the pH value is 1-2, stirring at room temperature for 2 hours, filtering, washing the filter cake twice with water, discharging to obtain 20.2g of a light yellow wet product, and drying at 40-50 ℃ to obtain 24.1g of a benzoylketone original drug product, wherein the quantitative content is 97.6%, and the yield is 88.9% (calculated on 2-chloro-4-methylsulfonyl-3- ((2,2, 2-trifluoroethoxy) methyl) benzoic acid).
Example 5
To the reaction mixture obtained in example 1, o-toluoylnitrile was replaced with 4-methanesulfonyl-2-nitrobenzoylnitrile (0.2g, 0.79mmol), giving a mesotrione quantitative content of 98.2% and a yield of 90.3% (based on 4-methanesulfonyl-2-nitrobenzoic acid).
Example 6
To the reaction mixture was added o-methylbenzonitrile according to the method of example 1 and the reaction was carried out at 60-65 ℃ for 4 hours to obtain mesotrione in a quantitative content of 92.5% and a yield of 78.2% (based on 4-methanesulfonyl-2-nitrobenzoic acid).
Comparative example 1
To the reaction mixture obtained in example 1, o-tolunitrile was replaced with acetone cyanohydrin (0.2g, 2.33mmol) to give mesotrione in a quantitative content of 95.6% and yield of 83.8% (based on 4-methanesulfonyl-2-nitrobenzoic acid).
Comparative example 2
To the reaction mixture obtained in example 1, o-tolunitrile was replaced with acetone cyanohydrin (0.4g, 4.65mmol) to give mesotrione in 97.2% quantitative yield of 85.6% (based on 4-methanesulfonyl-2-nitrobenzoic acid).
The above examples show that the catalyst of the invention has higher conversion efficiency, and compared with acetone cyanohydrin in the prior art, the rearrangement transposition catalyst of the invention with the same quality has higher yield, higher content of the obtained product, and is safer and more environment-friendly.
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