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CN-121974885-A - Process for the preparation of chlorofluoropyridine esters

CN121974885ACN 121974885 ACN121974885 ACN 121974885ACN-121974885-A

Abstract

The invention relates to the technical field of pesticide herbicides, and discloses a preparation method of chlorofluoropyridine ester shown in a formula (I). The preparation process of the chlorofluoropyridine ester and the key intermediate thereof based on the novel intermediate compound has the obvious advantages of mild reaction conditions, low cost of raw material reagents, less impurity generation, high reaction yield, high product content and the like.

Inventors

  • ZHOU DEFENG
  • CHEN JUNHUA
  • WU CHENGJUN
  • MAO CHUNHUI

Assignees

  • 永农生物科学有限公司

Dates

Publication Date
20260505
Application Date
20251231

Claims (10)

  1. 1. A compound represented by the formula (X): Wherein R 5 is selected from H, halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, C 1 -C 4 haloalkyl, C 1 -C 4 haloalkoxy, or nitro; R 6 is selected from OH or Cl; n is selected from any integer from 1 to 4.
  2. 2. A compound or salt thereof according to claim 1, wherein R 5 is selected from H, halogen, methyl, methoxy, halomethyl, halomethoxy or nitro; Alternatively, R 5 is selected from H, F, cl or Br, alternatively R 5 is H; and/or R 6 is OH or Cl; and/or n is 1 or 2; and/or, the compound represented by formula (X) is selected from the following compounds: wherein R 5 and n are as previously defined; optionally, R 5 is H and n is 1.
  3. 3. A compound represented by the formula (XI) or a salt thereof, Wherein R 7 is selected from H, benzyl or C 1 -C 12 alkyl; R 8 is selected from H or R 3 SO 2 , wherein R 3 is selected from substituted or unsubstituted C 1 -C 12 alkyl, substituted or unsubstituted C 6 -C 12 aryl or substituted or unsubstituted C 7 -C 15 aralkyl.
  4. 4. A compound according to claim 3, or a salt thereof, wherein R 7 is H or benzyl; And/or R 3 is selected from substituted or unsubstituted C 1 -C 3 alkyl, substituted or unsubstituted C 6 -C 8 aryl, or substituted or unsubstituted C 7 -C 9 aralkyl; Optionally, R 3 is selected from substituted C 1 -C 3 alkyl, substituted C 6 -C 8 aryl or substituted C 7 -C 9 aralkyl, optionally selected from substituted methyl, substituted phenyl or substituted benzyl; Optionally, the substituents in R 3 are each independently selected from at least one of halogen, cyano or nitro, optionally from at least one of fluoro, chloro, cyano or nitro, further optionally from at least one of fluoro, chloro or nitro; alternatively, R 3 is trichloromethyl; Alternatively, R 3 is trifluoromethyl; alternatively, R 3 is 2-nitrophenyl; Alternatively, R 3 is 3-nitrophenyl; alternatively, R 3 is 4-nitrophenyl; And/or, the compound represented by formula (XI) is selected from the following compounds: Wherein R 3 is as defined above and Bn is benzyl; alternatively, R 3 is trichloromethyl; Alternatively, R 3 is trifluoromethyl; alternatively, R 3 is 2-nitrophenyl; Alternatively, R 3 is 3-nitrophenyl; Alternatively, R 3 is 4-nitrophenyl.
  5. 5. A process for the preparation of a compound of formula (VI) or a salt thereof, comprising the steps of: (1) Reacting a compound represented by the formula (IX) in the presence of a first solvent and a first base And a compound represented by the formula (B1) or (B2) Generating a first reaction to obtain an intermediate compound A; (2) The intermediate compound A and R 4 OH are subjected to a second reaction in the presence of a first acid or a first dehydrating agent, or the intermediate compound A and R 4 Z are subjected to a third reaction in the presence of a second base to obtain a compound shown in a formula (VI), or, (2') Reacting the intermediate compound A with a chlorinating agent to obtain an intermediate compound B, and reacting the intermediate compound B with R 4 OH to obtain a compound represented by formula (VI); Wherein R 4 is selected from substituted or unsubstituted C 1 -C 12 alkyl, C 3 -C 12 alkynyl, C 3 -C 12 alkenyl, or C 7 -C 13 aralkyl; r 5 and n are as defined in claim 1 or 2; hal is selected from Cl or Br; Z is selected from halogen or R 3 SO 3 , wherein R 3 is as defined in claim 3 or 4.
  6. 6. The method of claim 5, wherein R 4 is C 1 -C 12 alkyl, optionally C 1 -C 7 alkyl; And/or R 4 is substituted with one or more cyano, halogen or nitro groups, optionally R 4 is substituted with one or more halogen; And/or, the structural formulas of the intermediate compound A and the intermediate compound B are shown by a formula (X): Wherein R 6 is as defined in claim 1 or 2; and/or the method comprises the steps of: (1) Reacting a compound represented by formula (IX) with a compound represented by formula (B1) or (B2) in the presence of a first solvent and a first base to give a compound of formula (VIII), ; (2) The compound shown in the formula (VIII) and R 4 OH are subjected to a second reaction in the presence of a first acid or a first dehydrating agent, or the compound shown in the formula (VIII) and R 4 Z are subjected to a third reaction in the presence of a second base to obtain the compound shown in the formula (VI), or, (2') Reacting the compound represented by the formula (VIII) with a chlorinating agent to give a compound represented by the formula (VII), ; Reacting the compound shown in the formula (VII) with R 4 OH to obtain a compound shown in the formula (VI); And/or, in the step (1), the first solvent is selected from at least one of a C 1 -C 12 nitrile solvent, an ether solvent, an alkane solvent, an aromatic hydrocarbon solvent, a ketone solvent, an amide solvent, and a sulfone or sulfoxide solvent, optionally from at least one of acetonitrile, propionitrile, butyronitrile, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ethylene glycol dimethyl ether, cyclohexane, methylcyclohexane, dichloromethane, chloroform, dichloroethane, benzene, toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidine, dimethyl sulfoxide, and sulfolane, further optionally from at least one of acetonitrile, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ethylene glycol dimethyl ether, cyclohexane, methylcyclohexane, dichloromethane, chloroform, toluene, xylene, acetone, methyl ethyl ketone, and methyl isobutyl ketone; And/or, in the step (1), the first base is selected from at least one of an inorganic base and a tertiary amine; Optionally, in step (1), the substituents on the nitrogen of the tertiary amine are each independently selected from C 1 -C 12 alkyl, C 6 -C 12 aryl, or C 7 -C 13 aralkyl, or form a five-membered or six-membered ring; Optionally, in the step (1), the first base is selected from lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium bicarbonate, sodium bicarbonate, potassium bicarbonate, lithium carbonate, sodium carbonate, potassium carbonate, trimethylamine, triethylamine, tri-N-propylamine, triisopropylamine, tributylamine, dimethylisopropylamine, diethylisopropylamine, diisopropylethylamine, N-dimethylcyclopentylamine, N-diethylcyclopentylamine, N-dipropylcyclopentylamine, N-diisopropylcyclopentylamine, N-dimethylcyclohexylamine, N, at least one of N-diethylcyclohexylamine, N-dipropylcyclohexylamine, N-diisopropylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, N-methylpyrrolidine, N-ethylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, N-dimethylaniline and 4-dimethylaminopyridine, optionally at least one of sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium carbonate, triethylamine, tri-N-propylamine, triisopropylamine, tributylamine, dimethylisopropylamine, diethylisopropylamine and diisopropylethylamine; and/or, in the step (1), the first alkali is added into the reaction system in a dropwise adding, batch adding or one-time adding mode; And/or, in the step (1), the compound shown in the formula (B1) or the formula (B2) is added into the reaction system in a dropwise adding, batch adding or one-time adding mode; And/or in the step (1), the temperature of the first reaction is 30-150 ℃, optionally 30-100 ℃, further optionally 50-90 ℃; And/or in the step (2), the first acid is selected from at least one of hydrochloric acid, hydrobromic acid, sulfuric acid and substituted sulfonic acid, optionally from at least one of hydrochloric acid, hydrobromic acid, sulfuric acid, methylsulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid and p-toluenesulfonic acid, further optionally from at least one of trifluoromethanesulfonic acid and sulfuric acid; And/or, in the step (2), the first dehydrating agent is at least one selected from dicyclohexylcarbodiimide, diisopropylcarbodiimide, 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide, thionyl chloride, phosphorus oxychloride, phosphorus trichloride and phosphorus pentachloride; And/or, in said step (2), said first dehydrating agent is used in combination with a catalyst, optionally a catalyst selected from 4-dimethylaminopyridine, N-hydroxysuccinimide or 1-hydroxybenzotriazole; And/or, in the step (2), the second base is a substituted or unsubstituted tertiary amine; Optionally, in step (2), the substituents on the nitrogen of the tertiary amine are each independently selected from C 1 -C 12 alkyl, C 6 -C 12 aryl, or C 7 -C 13 aralkyl, or form a five-membered or six-membered ring; Optionally, in the step (2), the second base is selected from trimethylamine, triethylamine, tri-N-propylamine, triisopropylamine, tributylamine, dimethylisopropylamine, diethylisopropylamine, diisopropylethylamine, N, N-dimethylcyclopentylamine, N-diethylcyclopentylamine, N-dipropylcyclopentylamine, N, N-diisopropylcyclopentylamine, N-dimethylcyclohexylamine, N-diethylcyclohexylamine, N-dipropylcyclohexylamine, N, at least one of N-diisopropylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, N-methylpyrrolidine, N-ethylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, N-dimethylaniline and 4-dimethylaminopyridine, optionally at least one of triethylamine, tri-N-propylamine, triisopropylamine, tributylamine, dimethylisopropylamine, diethylisopropylamine and diisopropylethylamine; And/or the temperature of the second reaction is 60-120 ℃; And/or the second reaction time is 24-48h; and/or the temperature of the third reaction is 20-100 ℃; And/or the time of the third reaction is 4-10h; and/or, in the step (2), the second reaction is performed in the presence of a second solvent; Optionally, in the step (2), the second solvent is selected from at least one of a C 1 -C 12 nitrile solvent, an ether solvent, an alkane solvent, an aromatic hydrocarbon solvent, a ketone solvent, an amide solvent, and a sulfone or sulfoxide solvent, optionally from at least one of acetonitrile, propionitrile, butyronitrile, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ethylene glycol dimethyl ether, cyclohexane, methylcyclohexane, dichloromethane, chloroform, dichloroethane, benzene, toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidine, dimethyl sulfoxide, and sulfolane, further optionally from at least one of acetonitrile, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ethylene glycol dimethyl ether, cyclohexane, methylcyclohexane, dichloromethane, chloroform, toluene, xylene, acetone, methyl ethyl ketone, and methyl isobutyl ketone; and/or, in the step (2), the third reaction is performed in the presence of a third solvent; Optionally, in the step (2), the third solvent is selected from at least one of a C 1 -C 12 nitrile solvent, an ether solvent, an alkane solvent, an aromatic hydrocarbon solvent, a ketone solvent, an amide solvent, and a sulfone or sulfoxide solvent, optionally from at least one of acetonitrile, propionitrile, butyronitrile, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ethylene glycol dimethyl ether, cyclohexane, methylcyclohexane, dichloromethane, chloroform, dichloroethane, benzene, toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidine, dimethyl sulfoxide, and sulfolane, further optionally from at least one of acetonitrile, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ethylene glycol dimethyl ether, cyclohexane, methylcyclohexane, dichloromethane, chloroform, toluene, xylene, acetone, methyl ethyl ketone, and methyl isobutyl ketone; and/or, in the step (2'), the fourth reaction is performed in the presence of a fourth solvent; Optionally, in the step (2'), the fourth solvent is selected from at least one of a C 1 -C 12 nitrile solvent, an ether solvent, an alkane solvent, an aromatic hydrocarbon solvent, a ketone solvent, an amide solvent, and a sulfone or sulfoxide solvent, optionally from at least one of acetonitrile, propionitrile, butyronitrile, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ethylene glycol dimethyl ether, cyclohexane, methylcyclohexane, dichloromethane, chloroform, dichloroethane, benzene, toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidine, dimethyl sulfoxide, and sulfolane, further optionally from at least one of acetonitrile, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ethylene glycol dimethyl ether, cyclohexane, methylcyclohexane, dichloromethane, chloroform, toluene, xylene, acetone, methyl ethyl ketone, and methyl isobutyl ketone; and/or, in the step (2'), the fifth reaction is performed in the presence of a fifth solvent; optionally, in the step (2'), the fifth solvent is selected from at least one of a C 1 -C 12 nitrile solvent, an ether solvent, an alkane solvent, an aromatic hydrocarbon solvent, a ketone solvent, an amide solvent, and a sulfone or sulfoxide solvent, optionally from at least one of acetonitrile, propionitrile, butyronitrile, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ethylene glycol dimethyl ether, cyclohexane, methylcyclohexane, dichloromethane, chloroform, dichloroethane, benzene, toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidine, dimethyl sulfoxide, and sulfolane, further optionally from at least one of acetonitrile, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ethylene glycol dimethyl ether, cyclohexane, methylcyclohexane, dichloromethane, chloroform, toluene, xylene, acetone, methyl ethyl ketone, and methyl isobutyl ketone; and/or, in the step (2'), the chlorinating agent is selected from at least one of thionyl chloride, phosgene, solid phosgene, phosphorus oxychloride and phosphorus trichloride; And/or in the step (2'), the temperature of the fourth reaction and the fifth reaction is 30 to 150 ℃, alternatively 30 to 100 ℃, further alternatively 50to 90 ℃; and/or the molar ratio of the first base to the compound of formula (IX) is (2-6): 1, alternatively (2.5-4): 1; and/or the molar ratio of the compound represented by formula (B1) or formula (B2) to the compound represented by formula (IX) is (1-4): 1, optionally (2-3): 1; And/or the molar ratio of the first acid to the compound of formula (IX) is (0.05-1): 1, alternatively (0.1-0.5): 1; and/or the molar ratio of the first dehydrating agent to the compound of formula (IX) is (1-3): 1, alternatively (1-1.5): 1; And/or the molar ratio of R 4 OH to the compound of formula (IX) is (1-10): 1, alternatively (1-2): 1; And/or the molar ratio of the second base to the compound of formula (IX) is (1-3): 1, alternatively (1-1.5): 1; and/or the molar ratio of R 4 Z to the compound of formula (IX) is (1-2): 1, alternatively (1-1.3): 1; and/or the molar ratio of the chlorinating agent to the compound of formula (IX) is (1-5): 1, alternatively (1.1-1.5): 1.
  7. 7. A process for the preparation of a chlorofluoropyridine ester of formula (I), comprising: Reacting a compound shown in a formula (II) with a compound shown in a formula (A) in the presence of a catalyst to obtain chlorofluoropyridine ester shown in a formula (I), Wherein R 1 and R 2 are each independently selected from H or C 1 -C 8 alkyl, or R 1 、R 2 together with the O atom, B atom to which they are attached form a five to eleven membered heterocycloalkyl; R 3 is as defined in claim 3 or 4 and Bn is benzyl.
  8. 8. The method of claim 7, wherein R 1 and R 2 are each independently selected from H or C 1 -C 3 alkyl, or R 1 、R 2 together with the O atom, B atom to which they are attached form a five to seven membered heterocycloalkyl; Alternatively, R 1 and R 2 are both H or methyl, or the compound shown in the formula (A) is 4-chloro-2-fluoro-3-methoxyphenylboronic acid glycol ester; And/or, the seventh reaction is performed in the presence of a sixth solvent; Optionally, the sixth solvent is selected from at least one of a C 1 -C 12 alcohol solvent, a C 1 -C 12 nitrile solvent, an ether solvent, an aromatic hydrocarbon solvent, a ketone solvent, an amide solvent, a sulfone or sulfoxide solvent, and water, optionally at least one of methanol, ethanol, propanol, isopropanol, acetonitrile, propionitrile, butyronitrile, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ethylene glycol dimethyl ether, benzene, toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidine, dimethyl sulfoxide, and water, further optionally at least one of acetonitrile, propionitrile, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ethylene glycol dimethyl ether, toluene, methyl isobutyl ketone, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidine, and water, still further optionally a mixed solvent of acetonitrile and water, a mixed solvent of tetrahydrofuran and water, methyl isobutyl ketone, and N-dimethylformamide, or at least one of N-dimethylformamide; And/or, the seventh reaction is carried out in the presence of a palladium or nickel catalyst and optionally a ligand; Optionally, the palladium catalyst is selected from at least one of palladium chloride, palladium bromide, palladium acetate, palladium sulfate, palladium nitrate and supported palladium catalyst, optionally at least one of palladium chloride, palladium acetate and palladium sulfate; Optionally, the ligand of the palladium catalyst is selected from at least one of tri-tert-butylphosphine, tricyclohexylphosphine, di-tert-butylphenylphosphine, dicyclohexylphenylphosphine, triphenylphosphine, tris (o-tolylphosphine), 1, 2-bis (diphenylphosphino) ethane, 1, 3-bis (diphenylphosphanyl) propane, 1, 4-bis (diphenylphosphino) butane and 1,1' -ferrocenediyl-bis (diphenylphosphine), optionally at least one of triphenylphosphine and tricyclohexylphosphine; Optionally, the palladium catalyst is a coordination compound of palladium, optionally at least one selected from bis (triphenylphosphine) palladium (II) dichloride, bis (acetogenized) bis (triphenylphosphine) palladium (II), tetrakis (triphenylphosphine) palladium (0), tris (dibenzylideneacetone) dipalladium (0) and dichloro di-tert-butyl- (4-dimethylaminophenyl) phosphine palladium (II), further optionally at least one selected from bis (triphenylphosphine) palladium (II) dichloride and bis (acetogenized) bis (triphenylphosphine) palladium (II); Optionally, the nickel catalyst is selected from at least one of nickel dichloride, nickel dibromide, nickel acetate, nickel sulfate, nickel nitrate, ethylene glycol dimethyl ether nickel bromide or supported nickel catalyst; Alternatively, the ligand of the nickel catalyst is selected from at least one of tri-tert-butylphosphine, tricyclohexylphosphine, di-tert-butylphenylphosphine, dicyclohexylphenylphosphine, triphenylphosphine, tris (o-tolylphosphine), 1, 2-bis (diphenylphosphino) ethane, 1, 3-bis (diphenylphosphalkyl) propane, 1, 4-bis (diphenylphosphino) butane, 1' -ferrocenediyl-bis (diphenylphosphine), 4' -di-tert-butyl-2, 2' -bipyridine, 4, 7-diphenyl-1, 10-phenanthroline, and 4,4' -dimethoxy-2, 2' -bipyridine; and/or the seventh reaction is carried out in the presence of a palladium catalyst in a molar ratio to the compound of formula (II) of (0.001-0.1): 1, optionally (0.002-0.05): 1; And/or, the seventh reaction is carried out in the presence of a palladium catalyst and a ligand to the palladium catalyst in a molar ratio of (1.8-18): 1, alternatively (2-8): 1; And/or the seventh reaction is carried out in the presence of a nickel catalyst in a molar ratio to the compound of formula (II) of (0.01-0.2): 1, optionally (0.03-0.1): 1; And/or, the seventh reaction is carried out in the presence of a third base; optionally, the third base is selected from at least one of an inorganic base and an organic base, optionally at least one of lithium bicarbonate, sodium bicarbonate, potassium bicarbonate, lithium carbonate, sodium carbonate, potassium bicarbonate, potassium dihydrogen phosphate, potassium phosphate, triethylamine, tripropylamine, and pyridine, optionally at least one of sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium hydrogen phosphate, and potassium dihydrogen phosphate; And/or the seventh reaction is at a temperature of 30-150 ℃, optionally 40-120 ℃, further optionally 50-90 ℃; and/or the seventh reaction is for a period of time ranging from 2 to 24 hours, alternatively from 5 to 12 hours; and/or the molar ratio of the compound represented by the formula (A) to the compound represented by the formula (II) is (0.95-1.2): 1, optionally (1-1.1): 1; and/or the molar ratio of the third base to the compound of formula (II) is (1.5-7): 1, alternatively (2-4): 1.
  9. 9. The method according to claim 7 or 8, wherein the compound represented by formula (II) is prepared by: (1) In the presence of water and a second acid or a fourth base, reacting a compound represented by formula (V) An eighth reaction is carried out to obtain a compound shown in a formula (IV), ; Wherein R 4 is as defined in claim 5 or 6, R 5 and n are as defined in claim 1 or 2, or, (1') Subjecting a compound represented by the formula (V) to a reduction reaction in the presence of a reducing agent to obtain a compound represented by the formula (IV); (2) Reacting the compound represented by the formula (IV) with BnZ in the presence of a fifth base to obtain a compound represented by the formula (III), Wherein Bn is benzyl and Z is as defined in claim 6, or, (2') Reacting a compound represented by the formula (IV) with benzyl alcohol in the presence of a second dehydrating agent to obtain a compound represented by the formula (III); (3) Reacting the compound of formula (III) with R 3 SO 2 Cl or (R 3 SO 2 ) 2 O) in the presence of a sixth base to give the compound of formula (II) wherein R 3 is as defined in claim 3 or 4, ; And/or, in the step (1), the temperature of the eighth reaction is 20-200 ℃; And/or the second acid is selected from at least one of inorganic acid and organic acid, optionally at least one of hydrochloric acid, hydrobromic acid, sulfuric acid, organic acid, substituted organic acid and substituted sulfonic acid, further optionally at least one of formic acid, acetic acid, propionic acid, trifluoroacetic acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, hydrochloric acid, hydrobromic acid and sulfuric acid, still further optionally at least one of acetic acid, trifluoroacetic acid, methanesulfonic acid, trifluoromethanesulfonic acid and sulfuric acid; and/or the fourth base is selected from at least one of an organic base and an inorganic base, optionally at least one of lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium carbonate, sodium carbonate and potassium carbonate, further optionally at least one of sodium hydroxide and potassium hydroxide; And/or, in the step (1'), the reducing agent is selected from at least one of hydrogen and hydrazine hydrate; and/or the temperature of the reduction reaction is 30-200 ℃, optionally 40-180 ℃, further optionally 50-100 ℃; And/or, the reduction reaction is carried out in the presence of an inert solvent; and/or, in the step (2'), the second dehydrating agent is selected from at least one of dicyclohexylcarbodiimide, diisopropylcarbodiimide and 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide; And/or, in said step (2'), said second dehydrating agent is used in combination with a catalyst, optionally selected from 4-dimethylaminopyridine, N-hydroxysuccinimide or 1-hydroxybenzotriazole; and/or the tenth reaction is at a temperature of 50-150 ℃, optionally 60-120 ℃; And/or, the ninth reaction and/or tenth reaction is performed in the presence of a seventh solvent; Optionally, the seventh solvent is selected from at least one of a C 1 -C 12 nitrile solvent, an ether solvent, an aromatic hydrocarbon solvent, a ketone solvent, an amide solvent, and a sulfone or sulfoxide solvent, optionally from at least one of acetonitrile, propionitrile, butyronitrile, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ethylene glycol dimethyl ether, benzene, toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidine dimethyl sulfoxide, and sulfolane, further optionally from at least one of N, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidine, dimethyl sulfoxide, and sulfolane; and/or, the fifth base is one or more tertiary amines; Alternatively, the substituent on the nitrogen of the tertiary amine is selected from C 1 -C 12 alkyl, C 6 -C 12 aryl, or C 7 -C 13 aralkyl, or forms a five-membered or six-membered ring; Optionally, the fifth base is selected from trimethylamine, triethylamine, tri-N-propylamine, triisopropylamine, tributylamine, dimethylisopropylamine, diethylisopropylamine, diisopropylethylamine, N-dimethylcyclopentylamine, N, N-diethyl cyclopentylamine, N-dipropyl cyclopentylamine, N-diisopropyl cyclopentylamine, N, N-dimethylcyclohexylamine, N-diethylcyclohexylamine, N-dipropylcyclohexylamine, N, at least one of N-diisopropylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, N-methylpyrrolidine, N-ethylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, N-dimethylaniline and 4-dimethylaminopyridine, optionally at least one of triethylamine, tri-N-propylamine, triisopropylamine, tributylamine, dimethylisopropylamine, diethylisopropylamine and diisopropylethylamine; and/or, the fifth alkali is added into the reaction system by dripping or portioning; and/or, the BnZ is added into the reaction system in a dropwise manner; and/or the temperature of the ninth reaction is 30-150 ℃, alternatively 40-100 ℃, further alternatively 60-90 ℃; And/or, the ninth reaction is a continuous reaction; And/or, the fourteenth reaction is performed in the presence of an eighth solvent; Optionally, the eighth solvent is selected from at least one of a C 1 -C 12 nitrile solvent, an ether solvent, an alkane solvent, an aromatic solvent, a ketone solvent, an amide solvent, and a sulfone or sulfoxide solvent, optionally from at least one of acetonitrile, propionitrile, butyronitrile, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ethylene glycol dimethyl ether, cyclohexane, methylcyclohexane, dichloromethane, chloroform, dichloroethane, benzene, toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidine, dimethyl sulfoxide, and sulfolane, further optionally from at least one of acetonitrile, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ethylene glycol dimethyl ether, cyclohexane, methylcyclohexane, dichloromethane, chloroform, dichloroethane, toluene, xylene, acetone, methyl ethyl ketone, and methyl isobutyl ketone; And/or, the sixth base is at least one of an inorganic base and a tertiary amine; Alternatively, the substituent on the nitrogen of the tertiary amine is selected from C 1 -C 12 alkyl, C 6 -C 12 aryl, or C 7 -C 13 aralkyl, or forms a five-membered or six-membered ring; Alternatively, the sixth base is selected from lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium bicarbonate, sodium bicarbonate, potassium bicarbonate, lithium carbonate, sodium carbonate, potassium carbonate, trimethylamine, triethylamine, tri-N-propylamine, triisopropylamine, tributylamine, dimethylisopropylamine, diethylisopropylamine, diisopropylethylamine, N, N-dimethylcyclopentylamine, N-diethylcyclopentylamine, N-dipropylcyclopentylamine, N, N-diisopropylcyclopentylamine, N-dimethylcyclohexylamine, N-diethylcyclohexylamine, N, at least one of N-dipropylcyclohexylamine, N-diisopropylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, N-methylpyrrolidine, N-ethylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, N-dimethylaniline and 4-dimethylaminopyridine, optionally at least one of sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium carbonate, triethylamine, tri-N-propylamine, triisopropylamine, tributylamine, dimethylisopropylamine, diethylisopropylamine and diisopropylethylamine; and/or, adding the sixth alkali into the reaction system by dripping, adding in batches or adding in one time; And/or, adding R 3 SO 2 Cl or (R 3 SO 2 ) 2 O into the reaction system in a dropwise manner; and/or the temperature of the fourteenth reaction is from-10 to 100 ℃, alternatively from 0 to 50 ℃, further alternatively from 0 to 20 ℃; And/or the molar ratio of the second acid to the compound of formula (V) is (0.5-100): 1, alternatively (5-20): 1; And/or the molar ratio of the fourth base to the compound of formula (V) is (4-10): 1, alternatively (6-8): 1; And/or the molar ratio of the reducing agent to the compound of formula (V) is (2-20): 1, alternatively (4-10): 1; and/or the molar ratio of the fifth base to the compound of formula (V) is (1-4): 1, alternatively (1-1.5): 1; and/or the molar ratio of BnZ to the compound of formula (V) is (1-4): 1, alternatively (1-1.5): 1; And/or the molar ratio of the second dehydrating agent to the compound of formula (V) is (1-5): 1, alternatively (2-3): 1; and/or the molar ratio of benzyl alcohol to the compound of formula (V) is (1-6): 1, alternatively (1.5-2): 1; And/or the molar ratio of the sixth base to the compound of formula (V) is (1-5): 1, alternatively (1-2): 1; And/or the molar ratio of R 3 SO 2 Cl to the compound of formula (V) is (1-5): 1, alternatively (1-2): 1; and/or the molar ratio of (R 3 SO 2 ) 2 O) to the compound of formula (V) is (1-6): 1, alternatively (1-2): 1.
  10. 10. A process for the preparation of chlorofluoropyridine esters of formula (I), comprising the steps of: (1) Preparing a compound of formula (VI) from a compound of formula (IX) by the method of claim 5 or 6; (2) Reacting a compound shown in a formula (VI) with a fluorinating agent to obtain a compound shown in a formula (V); (3) Preparing a chlorofluoropyridine ester of formula (I) from a compound of formula (V) by the process of claim 9; optionally, in the step (2), the fluorinating agent is selected from at least one of hydrogen fluoride, sodium fluoride, potassium fluoride, cesium fluoride, tetramethyl ammonium fluoride, tetraethyl ammonium fluoride, tetrapropyl ammonium fluoride, tetrabutyl ammonium fluoride, diethylaminosulfur trifluoride and 1-chloromethyl-4-fluoro-1, 4-diazabicyclo [2.2.2] octane bis (tetrafluoroboric acid) salt, optionally at least one of sodium fluoride, potassium fluoride and cesium fluoride, further optionally at least one of sodium fluoride and potassium fluoride; Optionally, in the step (2), the sixth reaction is performed in the presence of a phase transfer catalyst, optionally at least one of polyethers, cyclic crown ethers and quaternary ammonium salts, further optionally at least one of polyethers selected from PEG400, PEG600 and polyethylene glycol dimethyl ether, at least one of 18 crown 6, 15 crown 5 and cyclodextrin, at least one of tetrabutylammonium chloride, tetramethylammonium bromide, tetrabutylammonium hydrogen sulfate, trioctyl methyl ammonium chloride, dodecyltrimethyl ammonium chloride, tetradecyltrimethylammonium chloride and benzyltriethyl ammonium chloride, and still further optionally at least one of PEG400, tetramethylammonium chloride and tetrabutylammonium chloride; Optionally, the sixth reaction is performed in the presence of a polar solvent, optionally the polar solvent is selected from at least one of an amide-based solvent and a sulfone or sulfoxide-based solvent, further optionally at least one of N, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidine, dimethylsulfoxide and sulfolane, still further optionally at least one of N-methylpyrrolidine, dimethylsulfoxide and sulfolane; and/or the temperature of the sixth reaction is 30-150 ℃, alternatively 30-120 ℃, further alternatively 50-100 ℃; and/or, the sixth reaction time is 4-18h; and/or the molar ratio of the fluorinating agent to the compound of formula (IX) is (2-10): 1, alternatively (2-4): 1.

Description

Process for the preparation of chlorofluoropyridine esters Technical Field The invention relates to the technical field of pesticide herbicides, in particular to a preparation method of chlorofluoropyridine ester shown in a formula (I). Background Chlorofluoropyridine esters are novel, highly effective herbicides developed by the dow. The prior literature uses benzyl 6-chloro (bromo) picolinate for coupling reaction to synthesize chlorofluoropyridine ester. CN115298167a discloses a method for synthesizing chlorofluoropyridine esters using benzyl 6-bromopyridine formate (A2) for coupling. The yield of the coupling step was 89%, the phenylboronic acid (or ester, B1) was used in a large excess (20.8%), and phenylboronic acid (B1) was expensive, which resulted in an increase in cost, and impurities produced from phenylboronic acid (or ester, B1) were difficult to remove. In addition, the two-step yield of esterification and diacylation is only 80-88 percent, the reaction time of the esterification step is long, decarboxylation impurities are easy to generate, a large amount of alcohol solvents are used, and the recovery treatment difficulty is high. The three-step yield of the benzyl bromide esterification is only 44.4-87.3 percent, and the bromination step uses a large excessive hydrogen bromide acetic acid solution, and the excessive hydrogen bromide is difficult to recycle, thus leading to the great increase of cost. CN115551833a discloses a process using benzyl 6-chloro (bromo) picolinate coupling in yields of only 74-81%. CN115819334a discloses a method for coupling using copper iodide to catalyze benzyl 6-bromopyridine carboxylate (compound a). The method has the advantages of high price, high dosage of cuprous iodide and cesium carbonate, difficult recovery of the cuprous iodide, increased cost, serious pollution caused by the large dosage of N ligand and phase transfer catalyst, high crude product yield, but only 84.2 percent of purified yield, unstable reaction temperature of 120 ℃ and more excessive requirement of compound B, and long reaction time of 24 hours. The benzyl 6-chloro (bromo) picolinate has a low activity, requires a large excess of phenylboronic acid or is carried out at high temperature, and has a low yield, and therefore it is desirable to provide a more active compound for coupling in order to obtain a higher yield. In addition, the overall process for preparing chlorofluoropyridine esters from picloram as a starting material needs to be optimized. Disclosure of Invention The invention aims to overcome the problems in the prior art and provides a preparation method of chlorofluoropyridine ester. In order to achieve the above object, a first aspect of the present invention provides a compound represented by the formula (X): Wherein R 5 is selected from H, halogen, C 1-C4 alkyl, C 1-C4 alkoxy, C 1-C4 haloalkyl, C 1-C4 haloalkoxy, or nitro; R 6 is selected from OH or Cl; n is selected from any integer from 1 to 4. In a second aspect, the present invention provides a compound represented by the formula (XI) or a salt thereof, Wherein R 7 is selected from H, benzyl or C 1-C12 alkyl; R 8 is selected from H or R 3SO2, wherein R 3 is selected from substituted or unsubstituted C 1-C12 alkyl, substituted or unsubstituted C 6-C12 aryl or substituted or unsubstituted C 7-C15 aralkyl. In a third aspect, the present invention provides a process for producing a compound represented by formula (VI) or a salt thereof, wherein the process comprises the steps of: (1) Reacting a compound represented by the formula (IX) in the presence of a first solvent and a first base And a compound represented by the formula (B1) or (B2) Generating a first reaction to obtain an intermediate compound A; (2) The intermediate compound A and R 4 OH are subjected to a second reaction in the presence of a first acid or a first dehydrating agent, or the intermediate compound A and R 4 Z are subjected to a third reaction in the presence of a second base to obtain a compound shown in a formula (VI), or, (2') Reacting the intermediate compound A with a chlorinating agent to obtain an intermediate compound B, and reacting the intermediate compound B with R 4 OH to obtain a compound represented by formula (VI); Wherein R 4 is selected from substituted or unsubstituted C 1-C12 alkyl, C 3-C12 alkynyl, C 3-C12 alkenyl, or C 7-C13 aralkyl; R 5 and n are as defined in the first aspect; hal is selected from Cl or Br; Z is selected from halogen or R 3SO3, wherein R 3 is as defined in the second aspect. According to a fourth aspect of the present invention, there is provided a process for the preparation of a chlorofluoropyridine ester of formula (I), wherein said process comprises: Reacting a compound shown in a formula (II) with a compound shown in a formula (A) in the presence of a catalyst to obtain chlorofluoropyridine ester shown in a formula (I), Wherein R 1 and R 2 are each independently selected from H or C 1-C8 alkyl, or R 1、R2