Preparation method of fluorosulfone

Abstract

The present invention relates to a method for preparing 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2 A process for the oxidation of thiazole and its analogs to the corresponding sulfones using an oxidizing agent and a metal oxide-based catalyst.

Description

Technical Field

[0001] The present invention relates to 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2 -thiazole(5-chloro-2-((3,4,4-trifluorobut-3-en-1-yl)thio)-1λ 3 ,3λ 2 -thiazole) and its analogs are oxidized to the corresponding sulfones, 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole(5-chloro-2-((3,4,4-trifluorobut-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole) (Fluensulfone) and its corresponding analogs, using several catalysts based on metal oxides and an oxidant. Background Art

[0002] Flusulfuron (5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole)(5-chloro-2-((3,4,4-trifluorobut-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole) is a nematicide effective against many plant parasites and nematodes in various agricultural and horticultural crops. One of its synthesis methods involves oxidation of the corresponding sulfide 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2 -thiazole(5-chloro-2-((3,4,4-trifluorobut-3-en-1-yl)thio)-1λ 3 ,3λ 2 WO / 2001 / 002378 describes the oxidation of sulfides with a peroxy agent (eg 3-chlorobenzoic acid or hydrogen peroxide) in the presence of a carboxylic acid (eg acetic acid).

[0003] It was reported that the reaction with 3 equivalents of H2O2 in acetic acid at 60°C gave prosulfuron in 76% yield.

[0004] The yield is improved by oxidation of sulfides with Oxone or Caroat (a triple salt 2KHSO5.KHSO4.K2SO4 with potassium peroxymonosulfate as the active oxidant) (US Pat. No. 8,901,311, WO / 2004 / 005268).

[0005] Although the use of 2KHSO5.KHSO4.K2SO4 (US Pat. No. 8,901,311) has been reported to improve yields compared to the use of H2O2 (WO / 2001 / 002378), large amounts of environmentally harmful sulfates are introduced and formed in the reaction, while only water and H2O2 are formed.

[0006] The problem with using H2O2, as also described in US 8,901,311, is that the intermediate sulfoxide is more difficult to oxidize, resulting in a rather low yield. Therefore, the further oxidation of the sulfoxide to the sulfone proceeds only gradually and slowly and requires higher temperatures and longer reaction times. Even more problematic is that once the sulfone is formed, it reacts further by oxidative cleavage of the fluorinated double bond, thereby producing the undesirable byproduct 3-((5-chloro-1λ 3 ,3λ 2 -thiazol-2-yl)sulfonyl)propanoic acid (3-((5-chloro-1λ 3 ,3λ 2 The reaction is presumably a result of a non-catalytic nucleophilic attack of H2O2, mainly on the double bond of the sulfone, which is very electrophilic due to the presence of the fluorine substituent and the adjacent sulfone group. Therefore, even in the absence of any catalyst, 3-((5-chloro-1λ-thiazol-2-yl)sulfonyl)propanoic acid is observed upon reaction of the sulfone with H2O2 due to the cleavage of the double bond. 3 ,3λ 2 The formation of 2-(4-thiazol-2-yl)sulfonyl)propionic acid and HF. The reactive oxidizing peracids also undergo this undesirable side reaction with H2O2 in the presence of formic acid or acetic acid or in the presence of commonly used molybdate or tungstate catalysts.

[0007] The present invention provides a method for preparing 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2 -thiazole and its analogs are selectively oxidized to the corresponding sulfone, 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ2 -thiazole and its corresponding analogs, using aqueous H2O2 as the oxidant / oxygen donor in a biphasic reaction medium in an aqueous solution.

[0008] A particular advantage of using an aqueous biphasic reaction medium is the ease with which the aqueous phase containing the catalyst and the organic phase containing the desired product can be separated. In this way, the catalyst can be recovered and reused very simply. Summary of the invention

[0009] In one embodiment, the present invention provides a method for preparing a compound represented by a structure of formula (I):

[0010]

[0011] wherein R is a heterocycle selected from thiophene, thiazole, isothiazole, thiadiazole and thiatriazole, wherein the heterocycle is optionally halogenated; and n is an integer between 1 and 6. The method comprises the steps of contacting a compound represented by a structure of formula (Ia) in a reaction mixture:

[0012]

[0013] wherein R and n are as defined above in H2O2 in an acidic aqueous phase in the presence of a catalyst.

[0014] In another embodiment, the present invention provides a method for preparing 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole(5-chloro-2-((3,4,4-trifluorobut-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole) method, comprising making 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ 3 ,3λ 2 - A step of contacting thiazole with H2O2 in an acidic aqueous phase in the presence of a catalyst.

[0015] In one embodiment, the present invention provides a method for preparing a compound represented by the structure of formula (I):

[0016]

[0017] wherein R is a heterocycle selected from thiophene, thiazole, isothiazole, thiadiazole and thiatriazole, wherein the heterocycle is optionally halogenated; and n is an integer between 1 and 6, the method comprising the step of contacting a compound represented by a structure of formula (Ia) in a reaction mixture:

[0018]

[0019] wherein R and n are as defined above, a peroxygen oxidant is used in an acidic aqueous phase in the presence of a catalyst.

[0020] In another embodiment, the present invention provides a method for preparing 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole method, comprising making 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ 3 ,3λ 2 - A step of contacting thiazole with a peroxy oxidizing agent in an acidic aqueous phase in the presence of a catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to its organization and method of operation, together with objects, features, and advantages thereof, may be best understood by reference to the following detailed description when read with the several accompanying drawings, wherein:

[0022] Figure 1 The present invention shows a method for preparing 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole(5-chloro-2-((3,4,4-trifluorobut-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole), wherein the method of the present invention prevents 3-((5-chloro-1λ 3 ,3λ 2 -thiazol-2-yl)sulfonyl)propanoic acid (3-((5-chloro-1λ 3 ,3λ 2 -thiazol-2-yl)sulfonyl)propanoic acid) by-product.

[0023] It should be understood that for simplicity and clarity of illustration, the elements shown in the figures are not necessarily drawn to scale. For example, for clarity, the dimensions of some elements may be exaggerated relative to other elements. In addition, where deemed appropriate, several element symbols may be repeated in the several figures to indicate several corresponding or similar elements. DETAILED DESCRIPTION

[0024] In the following detailed description, many specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be appreciated by those skilled in the art that the present invention may be practiced without these specific details. In other cases, well-known methods, procedures, and components are not described in detail to avoid obscuring the present invention.

[0025] The present invention relates to 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2 -thiazole(5-chloro-2-((3,4,4-trifluorobut-3-en-1-yl)thio)-1λ 3 ,3λ 2 -thiazole) and its analogs are oxidized to the corresponding 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole(5-chloro-2-((3,4,4-trifluorobut-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole) (Fluensulfone) and its corresponding analogs, using a metal oxide-based catalyst and an oxidant. In another embodiment, the oxidant is a peroxy oxidant. In another embodiment, the oxidant is H2O2.

[0026] In one embodiment, the method of the present invention uses an oxidant. In another embodiment, the oxidant is a water-soluble peroxy oxidant. Non-limiting examples of a water-soluble peroxy oxidant include H2O2, magnesium monoperoxyphthalate, sodium perborate, sodium percarbonate, urea hydrogen peroxide (UHP), or any combination thereof. In another embodiment, the peroxy oxidant is H2O2. In another embodiment, the peroxy oxidant is magnesium monoperoxyphthalate. In another embodiment, the peroxy oxidant is sodium perborate. In another embodiment, the peroxy oxidant is sodium percarbonate. In another embodiment, the peroxy oxidant is urea hydrogen peroxide (UHP). In another embodiment, the peroxy oxidant forms hydrogen peroxide under acidic reaction conditions.

[0027] In one embodiment, the present invention provides a method for preparing a compound represented by a structure of formula (I):

[0028]

[0029] wherein R is a heterocycle selected from thiophene, thiazole, isothiazole, thiadiazole and thiatriazole, wherein the heterocycle is optionally halogenated; and n is an integer between 1 and 6, comprising the step of contacting a compound represented by a structure of formula (Ia) in a reaction mixture:

[0030]

[0031] wherein R and n are as defined above in H2O2 in an acidic aqueous phase in the presence of a catalyst.

[0032] In one embodiment, the present invention provides a method for preparing a compound represented by a structure of formula (I):

[0033]

[0034] wherein R is a heterocycle selected from thiophene, thiazole, isothiazole, thiadiazole and thiatriazole, wherein the heterocycle is optionally halogenated; and n is an integer between 1 and 6, comprising the step of contacting a compound represented by the structure of formula (Ia) in a reaction mixture:

[0035]

[0036] wherein R and n are as defined above, a peroxy oxidant is used in an acidic aqueous phase in the presence of a catalyst.

[0037] In another embodiment, the present invention provides a method for preparing a compound represented by a structure of formula (II) or (III):

[0038]

[0039]

[0040] Where X 1 To X 3 Each independently selected from: CH, CF, C-Cl, C-Br, CI and N; n is an integer between 1 and 6; comprising the step of contacting a compound represented by structure (IIa) or (IIIa) in a reaction mixture:

[0041]

[0042] In the presence of a catalyst with H2O2 in an acidic aqueous phase; wherein X 1 To X 3 and n is as defined above.

[0043] In another embodiment, the present invention provides a method for preparing a compound represented by a structure of formula (II) or (III):

[0044]

[0045] Where X 1 To X 3 Each is independently selected from: CH, CF, C-Cl, C-Br, CI and N; n is an integer between 1 and 6; the method comprises the step of contacting a compound represented by a structure (IIa) or (IIIa) in a reaction mixture:

[0046]

[0047] In the presence of a catalyst, a peroxy oxidant is used in an acidic aqueous phase; wherein X 1 To X 3 and n is as defined above.

[0048] In another embodiment, X 3 Selected from: CH, CF, C-Cl, C-Br and CI; X 1 and X 2 are each independently selected from CH and N.

[0049] In another embodiment, the present invention relates to a method for preparing 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2-Thiazole is oxidized to the corresponding sulfone, which is 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole (prosulfuron), using a metal oxide based catalyst and an oxidant. In another embodiment, the oxidant is a peroxy oxidant. In another embodiment, the oxidant is H2O2.

[0050] In one embodiment, the present invention is a method for preparing 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole or its analogues, the method comprising the steps of: in the presence of a catalyst in an acidic aqueous phase, reacting 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ of formula Ia, IIa or IIa in a reaction mixture; 3 ,3λ 2 -thiazole or its corresponding analog is contacted with H2O2. In another embodiment, the present invention is a method for preparing 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole (prosulfuron) method, comprising in an acidic aqueous phase a reaction mixture 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2 -thiazole reacts with H in the presence of a catalyst 2 O 2 Aqueous solution contact step.

[0051] In one embodiment, the present invention is a method for preparing 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole or its analogues, comprising the steps of: in the presence of a catalyst in an acidic aqueous phase, reacting 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2 -thiazole or its corresponding analog is contacted with a water-miscible peroxy oxidant. In another embodiment, the present invention is a method for preparing 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2-thiazole (prosulfuron) method, comprising reacting 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ in a reaction mixture 3 ,3λ 2 - A step of contacting the thiazole with a water-soluble peroxygen oxidizing agent in a reaction mixture in an acidic aqueous phase in the presence of a catalyst.

[0052] In one embodiment, the method for preparing 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole or its analogs of formula I-III, using a catalyst. In another embodiment, the catalyst is at least one metal oxide or metal oxide salt. In another embodiment, the metal oxide comprises: tungsten oxide, molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, rhenium oxide, titanium oxide, zirconium oxide, chromium oxide, hafnium oxide or a combination thereof.

[0053] In another embodiment, the catalyst is of formula M q M'O x at least one metal oxide salt,

[0054] in:

[0055] M is hydrogen, an alkali metal or an alkaline earth metal;

[0056] M' is titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum, rhenium or tungsten;

[0057] X is an integer between 2 and 6; and

[0058] q is an integer between 1 and 4.

[0059] In another embodiment, Formula M q M'O x In another embodiment, M is hydrogen, sodium, potassium, calcium or magnesium. In another embodiment, the formula M q M'O x M' is titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum, rhenium or tungsten. In another embodiment, the formula M q M'O x In another embodiment, x is an integer between 2 and 6. In another embodiment, x is 2, 3, 4, 5 or 6. In another embodiment, Formula M q M'O x Wherein q is an integer between 1 and 4. In another embodiment, q is 1, 2, 3 or 4.

[0060] In another embodiment, the at least one metal oxide salt is sodium vanadate, sodium molybdate or sodium tungstate or a combination thereof. In another embodiment, the metal oxide salt is sodium tungstate.

[0061] In another embodiment, the catalyst is hydrated.

[0062] In another embodiment, relative to the starting material 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2 -thiazole or its analogue, the concentration of the catalyst in the reaction mixture is between 0.01 mol% and 20 mol%. In another embodiment, relative to 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)thio)-1λ 3 ,3λ 2 -thiazole or its analogue, the concentration of the catalyst in the reaction mixture is between 1 mol% and 10 mol%. In another embodiment, relative to 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)thio)-1λ 3 ,3λ 2 -thiazole or its analogue, the concentration of the catalyst in the reaction mixture is between 1 mol% and 5 mol%. In another embodiment, relative to 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)thio)-1λ 3 ,3λ 2 -thiazole or its analogue, the concentration of the catalyst in the reaction mixture is between 0.01 mol% and 1 mol%. In another embodiment, relative to 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2 -thiazole or its analogue, the concentration of the catalyst in the reaction mixture is between 0.01 mol% and 2 mol%. In another embodiment, relative to 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2 -thiazole or its analogue, the concentration of the catalyst in the reaction mixture is between 0.01 mol% and 3 mol%. In another embodiment, relative to 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ2 -thiazole or its analogue, the concentration of the catalyst in the reaction mixture is between 0.01 mol% and 4 mol%. In another embodiment, relative to 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2 -thiazole or its analogue, the concentration of the catalyst in the reaction mixture is between 0.01 mol% and 5 mol%. In another embodiment, relative to 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)thio)-1λ 3 ,3λ 2 -thiazole or its analogue, the concentration of the catalyst in the reaction mixture is between 0.01 mol% and 8 mol%. In another embodiment, relative to 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)thio)-1λ 3 ,3λ 2 -thiazole or the like, said concentration of said catalyst in said reaction mixture is between 0.01 mol% and 10 mol%.

[0063] In another embodiment, the catalyst is recycled and reused. In another embodiment, the catalyst is reused. In another embodiment, the catalyst is not separated and reused in the reaction mixture.

[0064] In one embodiment, the method for preparing 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole or its analog of formula I, II or III uses an acidic aqueous solution. It has been found that the use of an acidic aqueous solution reduces the nucleophilicity of the hydrogen peroxide oxidizing agent, making it less reactive with the electrophilic trifluoroolefin moiety, especially when adjacent sulfone or sulfoxide groups are present, which inhibits the reaction of the double bond with a peroxy oxidizing agent (such as H2O2) and inhibits the reaction of 3-((5-chloro-1λ 3 ,3λ 2 -thiazol-2-yl)sulfonyl)propionic acid byproduct or its analog (e.g., formula (Ib to IIIb), see below). In another embodiment, the method for preparing the compound represented by formula (I) to (III):

[0065]

[0066] Producing less than 15% by weight of the corresponding by-product compounds represented by the several formulae (Ib) to (IIIb):

[0067] and

[0068]

[0069] Among them, R, X 1 To X 3 and n is as defined above. In another embodiment, the yield of the compounds of formula (Ib) to (IIIb) is between 0% by weight and 2% by weight. In another embodiment, the yield of the compounds of formula (Ib) to (IIIb) is between 2% by weight and 5% by weight. In another embodiment, the yield of the compounds of formula (Ib) to (IIIb) is between 5% by weight and 10% by weight. In another embodiment, the yield of the compounds of formula (Ib) to (IIIb) is between 10% by weight and 15% by weight. In another embodiment, the compounds of formula (Ib) to (IIIb) are used to prepare 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ 3 ,3λ 2 The method of -thiazole produced less than 2 wt% of 3-((5-chloro-1λ 3 ,3λ 2 -thiazol-2-yl)sulfonyl)propionic acid by-product.

[0070] In one embodiment, the method for preparing 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole or its analogs use an acidic aqueous solution. In another embodiment, the acidic aqueous phase comprises HCl, HBr, H2SO4, H3PO4, MeSO3H, CF3SO3H or a combination thereof. In another embodiment, the acidic aqueous phase comprises H2SO4. In another embodiment, the acid concentration in the acidic aqueous phase is between 0.5M and 8M. In another embodiment, the acid concentration in the acidic aqueous phase is between 1M and 6M. In another embodiment, the acid concentration in the acidic aqueous phase is between 2M and 5M.

[0071] In one embodiment, the method for preparing 5-chloro-2-((3,4,4-trifluorobut-3-ene-1-yl)sulfonyl)-1λ 3 ,3λ 2In another embodiment, the oxidant is a peroxy oxidant. In another embodiment, the oxidant is H2O2. In another embodiment, relative to 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)thio)-1λ 3 ,3λ 2 In another embodiment, relative to 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2 -thiazole or the like is 2 to 5 molar equivalents, and the oxidant is added. In another embodiment, relative to 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)thio)-1λ 3 ,3λ 2 -thiazole or its analogue, the oxidant is added in an amount between 3 molar equivalents and 3.5 molar equivalents. In another embodiment, the concentration of the aqueous hydrogen peroxide solution used is 3% to 90% by volume (i.e., the commercial concentration of aqueous hydrogen peroxide solution). In another embodiment, the concentration of the aqueous hydrogen peroxide solution used is 20% to 60% by weight (i.e., the commercial concentration of aqueous hydrogen peroxide solution).

[0072] In one embodiment, the method for preparing 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ 3 ,3λ 2 The reaction mixture of -thiazole or its analog is biphasic. In another embodiment, biphasic refers to an aqueous phase and an organic phase, the aqueous phase comprises an oxidant, a catalyst and an acid, and the organic phase comprises the sulfide substrate, the sulfone product and optionally a water-immiscible organic solvent. In another embodiment, biphasic refers to an aqueous phase and an organic phase, the aqueous phase comprises an oxidant, a catalyst and an acid, and the organic phase comprises the sulfide substrate and the sulfone product without a water-immiscible organic solvent.

[0073] In one embodiment, the method for preparing 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ 3 ,3λ 2 The method of using thiazole or its analogues is a single-phase reaction.

[0074] In one embodiment, the method for preparing 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ 3 ,3λ 2-The reaction mixture of thiazole or its analogue comprises water and does not comprise an organic solvent that is immiscible with water. In another embodiment, the reaction mixture comprises water and an organic solvent that is immiscible with water. Several non-limiting examples of an organic solvent that is immiscible with water include hexane, pentane, toluene, methylcyclohexane, chlorobenzene, ethyl acetate and various ethers. In another embodiment, the reaction mixture comprises water and a solvent and / or a surfactant that is miscible with water. Several non-limiting examples of a solvent that is miscible with water include acetonitrile, methanol, ethanol, acetone, dimethylformamide, dimethylacetamide, n-methylpyrrolidone or a combination thereof. In another embodiment, the reaction mixture comprises water and an organic solvent and / or a surfactant that is immiscible with water.

[0075] In some embodiments, the surfactant may include, but is not limited to, polyalkylene glycol, alkoxylated alcohol, alkyl sulfate, or any combination thereof. In some embodiments, the surfactant includes polyalkylene glycol, alkoxylated alcohol, alkyl sulfate, or any combination thereof. Several non-limiting examples of several surfactants include polyethylene glycol (e.g., PEG400), polyoxyethylene lauryl ether (e.g., Brij35), dodecyl sulfate (e.g., SDS).

[0076] In one embodiment, the method for preparing 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ 3 ,3λ 2 The reaction of -thiazole or its analogue is carried out at a temperature range of 0°C to 100°C. In another embodiment, a temperature is between 20°C and 40°C. In another embodiment, a temperature is between 20°C and 50°C. In another embodiment, a temperature is between 20°C and 60°C. In another embodiment, a temperature is between 20°C and 70°C. In another embodiment, a temperature is between 25°C and 40°C. In another embodiment, a temperature is between 25°C and 50°C. In another embodiment, a temperature is between 25°C and 60°C. In another embodiment, a temperature is between 25°C and 70°C. In another embodiment, a temperature is between 26°C and 100°C. In another embodiment, a temperature is between 30°C and 80°C. In another embodiment, a temperature is between 10°C and 80°C. In another embodiment, a temperature is between 20°C and 80°C. In another embodiment, a temperature is between 10°C and 50°C. In another embodiment, a temperature is between 15°C and 35°C. In another embodiment, a temperature is at least 15°C. In another embodiment, a temperature is at least 20°C. In another embodiment, a temperature is at least 25°C.

[0077] In one embodiment, the present invention relates to the preparation of 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ by the method of the present invention. 3 ,3λ 2 In another embodiment, 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ of formula I-III prepared by the method of the present invention 3 ,3λ 2 -thiazole or its analogue has a purity of more than 97%. In another embodiment, 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ of formula I-III prepared by the method of the present invention 3 ,3λ 2 -thiazole or its analogue having not more than 1% by weight of 3-((5-chloro-1λ 3 ,3λ 2 -thiazol-2-yl)sulfonyl)propionic acid or its analog; in another embodiment, less than 2% by weight of 3-((5-chloro-1λ) represented by formula (Ib-IIIb) 3 ,3λ 2 -thiazol-2-yl)sulfonyl)propionic acid or the like, wherein the formula (Ib-IIIb) is as described above.

[0078] The following examples are provided to more fully illustrate the several preferred embodiments of the present invention. However, they should in no way be construed as limiting the broad scope of the present invention.

[0079] Several examples

[0080] Example 1

[0081] 5-Chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole(5-chloro-2-((3,4,4-trifluorobut-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 Preparation of -thiazole

[0082] The sulfide, 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2-thiazole (14 g, 54 mmol), 20 mL of 4 M sulfuric acid, 780 mg of Na2WO4 (2.3 mmol, 4 mol%), and then 7 mL of 60% H2O2 (140 mmol) were added dropwise over 2 hours. After 20 hours at 22°C, analysis of the reaction mixture by HPLC showed the total conversion of the starting material and the desired sulfone 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole was formed with a selectivity of 96%. The byproducts were 3% sulfoxide, 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfinyl)-1λ 3 ,3λ 2 -thiazole and 1% 3-((5-chloro-1λ 3 ,3λ 2 -thiazol-2-yl)sulfonyl)propionic acid. Yield - 14.7 g of prosulfuron.

[0083] Example 2

[0084] 5-Chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole(5-chloro-2-((3,4,4-trifluorobut-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 Preparation of -thiazole

[0085] The sulfide, 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2 -thiazole (14 g, 54 mmol), 20 mL of 4 M sulfuric acid, 780 mg of Na2WO4 (2.3 mmol, 4 mol%), and then 7 mL of 60% H2O2 (140 mmol) were added dropwise over 2 hours. After 7 hours at 35°C, analysis of the reaction mixture by HPLC showed the total conversion of the starting material and the desired sulfone 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -Thiazole was formed with a selectivity of 91%.

[0086] Example 3

[0087] 5-Chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ2 -thiazole(5-chloro-2-((3,4,4-trifluorobut-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 Preparation of -thiazole

[0088] The sulfide, 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2 -thiazole (14 g, 54 mmol), 20 mL of 4 M sulfuric acid, 390 mg of Na2WO4 (1.65 mmol, 2 mol%), and then 7 mL of 60% H2O2 (140 mmol) were added dropwise over 2 hours. After 20 hours at 22°C, analysis of the reaction mixture by HPLC showed the total conversion of the starting material and the desired sulfone 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -Thiazole was formed with a selectivity of 86%.

[0089] Example 4

[0090] 5-Chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole(5-chloro-2-((3,4,4-trifluorobut-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 Preparation of -thiazole

[0091] The sulfide, 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 , 3λ 2 -thiazole (14 g, 54 mmol), 20 mL of 4 M phosphoric acid, 780 mg of Na2WO4 (2.3 mmol, 4 mol%), and then 7 mL of 60% H2O2 (140 mmol) were added dropwise over 2 hours. After 20 hours at 22°C, analysis of the reaction mixture by HPLC showed the total conversion of the starting material and the desired sulfone 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -Thiazole was formed with a selectivity of 75% due to the extensive decomposition of H2O2.

[0092] Example 5

[0093] Several water cycle experiments

[0094] Using the procedure described in Example 1, the sulfide, 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole (14 g, 54 mmol), 20 mL of 4 M sulfuric acid, 780 mg of Na2WO4 (2.3 mmol, 4 mol%), and then 7 mL of 60% H2O2 (140 mmol) were added dropwise over 2 hours. After 20 hours at 22°C, analysis of the reaction mixture by HPLC showed the total conversion of the starting material and the desired prosulfuron, 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole was formed with a selectivity of 96%. After separation of the organic phase (comprising the sulfone product, excluding an organic solvent) from the aqueous phase, 33% of the aqueous phase was removed in order to keep the reaction volume constant after addition of 1 / 3 of the initial amount of Na2WO4, H2SO4 and H2O2. Cyclic experiments conducted in this manner showed that 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ 3 ,3λ 2 The conversion of -thiazole and the selectivity to prosulfuron were the same within the range of ±1%.

[0095] Example 6

[0096] 5-Chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole(5-chloro-2-((3,4,4-trifluorobut-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 Preparation of -thiazole

[0097] The sulfide, 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2A mixture of 1-thiazole (100 g, 370 mmol), 150 mL of 2M sulfuric acid, 5.5 g of Na2WO4 was then added dropwise at 10°C over 1.5 hours with 65 g of 50% H2O2 (955 mmol). The reaction mixture was stirred at room temperature for 30 minutes, then warmed to 40°C and stirred for 13 hours. The reaction mixture was analyzed by HPLC, showing the overall conversion of the starting material and the desired sulfone 5-chloro-2-((3,4,4-trifluorobut-3-en-1-yl)sulfonyl)-1λ 3 ,3λ 2 -Thiazole formation. The product was isolated in 77% yield and 97% selectivity.

[0098] Although certain features of the present invention have been illustrated and described herein, many modifications, substitutions, changes and equivalents are readily apparent to those skilled in the art. Therefore, it should be understood that the appended claims are intended to cover all such modifications and changes that fall within the true spirit of the invention.

Claims

1. A method for preparing a compound represented by a structure of formula (I): ， It is characterized in that The method comprises the steps of contacting a compound of formula (Ia) in a reaction mixture with H2O2 in an acidic aqueous phase in the presence of a sodium tungstate catalyst: ， wherein R is a heterocyclic ring selected from thiophene, thiazole, isothiazole, thiadiazole and thiatriazole, wherein the heterocyclic ring is optionally halogenated; n is an integer between 1 and 6; wherein the acidic aqueous phase comprises H2SO4 or H3PO4, wherein the concentration of the catalyst is 0.01 mol% to 20 mol% relative to the compound represented by the formula (I), wherein the reaction is carried out in a temperature range of 10°C to 80°C, wherein the acid concentration in the acidic aqueous phase is between 1M and 6M, and wherein 2 molar equivalents to 10 molar equivalents of H2O2 are added relative to the compound represented by the formula (I).

2. The method according to claim 1, characterized in that The compound of formula (I) is 5-chloro-2-((3,4,4-trifluorobutyl-3-ene-1-yl)sulfonyl)-1λ 3 ,3λ 2 -thiazole, and in the presence of the catalyst in the acidic aqueous phase, H2O2 and 5-chloro-2-((3,4,4-trifluorobutyl-3-en-1-yl)thio)-1λ 3 ,3λ 2 -Thiazole contact.

3. The method according to claim 1, characterized in that The catalyst is hydrated.

4. The method according to claim 2, characterized in that The catalyst is hydrated.

5. The method according to any one of claims 1 to 4, characterized in that The concentration of the catalyst is 1 mol% to 10 mol% relative to the compound represented by the formula (I).

6. The method according to claim 5, characterized in that The concentration of the catalyst is 1 mol% to 5 mol% relative to the compound represented by the formula (I).

7. The method according to any one of claims 1 to 4 and 6, characterized in that The acidic aqueous phase contains H2SO4.

8. The method according to claim 5, characterized in that The acidic aqueous phase contains H2SO4.

9. The method according to any one of claims 1 to 4, 6 and 8, characterized in that The acid concentration in the acidic aqueous phase is between 2M and 5M.

10. The method according to claim 5, characterized in that The acid concentration in the acidic aqueous phase is between 2M and 5M.

11. The method according to claim 7, characterized in that The acid concentration in the acidic aqueous phase is between 2M and 5M.

12. The method according to claim 1, characterized in that Aqueous H2O2 is used in a concentration between 3% and 90% by volume.

13. The method according to any one of claims 1 to 4, 6, 8 and 10 to 12, characterized in that The reaction mixture comprises water and does not comprise a water-immiscible organic solvent.

14. The method according to claim 5, characterized in that The reaction mixture comprises water and does not comprise a water-immiscible organic solvent.

15. The method according to claim 7, characterized in that The reaction mixture comprises water and does not comprise a water-immiscible organic solvent.

16. The method according to claim 9, characterized in that The reaction mixture comprises water and does not comprise a water-immiscible organic solvent.

17. The method according to any one of claims 1 to 4, 6, 8, 10 to 12 and 14 to 16, characterized in that The reaction is carried out at a temperature ranging from 10°C to 50°C.

18. The method according to claim 5, characterized in that The reaction is carried out at a temperature ranging from 10°C to 50°C.

19. The method according to claim 7, characterized in that The reaction is carried out at a temperature ranging from 10°C to 50°C.

20. The method of claim 9, wherein: The reaction is carried out at a temperature ranging from 10°C to 50°C.

21. The method of claim 13, wherein: The reaction is carried out at a temperature ranging from 10°C to 50°C.

22. The method of claim 17, wherein: The reaction is carried out at a temperature ranging from 15°C to 35°C.

23. The method according to any one of claims 18 to 21, characterized in that The reaction is carried out at a temperature ranging from 15°C to 35°C.

24. The method of any one of claims 1 to 4, 6, 8, 10 to 12, 14 to 16 and 18 to 22, characterized in that The catalyst is recycled.

25. The method of claim 5, wherein: The catalyst is recycled.

26. The method of claim 7, wherein: The catalyst is recycled.

27. The method of claim 9, wherein: The catalyst is recycled.

28. The method of claim 13, wherein: The catalyst is recycled.

29. The method of claim 17, wherein: The catalyst is recycled.

30. The method of claim 23, wherein: The catalyst is recycled.

31. A method for preparing a compound represented by the structure of formula (II) or (III): ;or , It is characterized in that The method comprises the steps of contacting a compound represented by formula (IIa) or (IIIa) in a reaction mixture with H2O2 in an acidic aqueous phase in the presence of a sodium tungstate catalyst: ;or , Where X 1 To X 3 Each is independently selected from: CH, CF, C-Cl, C-Br, CI and N; n is an integer between 1 and 6; wherein the acidic aqueous phase comprises H2SO4 or H3PO4, wherein the concentration of the catalyst is 0.01 mol% to 20 mol% relative to the compound represented by the formula (II) or (III), wherein the reaction is carried out in a temperature range of 10°C to 80°C, wherein the acid concentration in the acidic aqueous phase is between 1M and 6M, and wherein 2 molar equivalents to 10 molar equivalents of H2O2 are added relative to the compound represented by the formula (II) or (III).

32. The method of claim 31, wherein: The catalyst is hydrated.

33. The method of claim 31, wherein: The concentration of the catalyst is 1 mol% to 10 mol% relative to the compound represented by the formula (II) or (III).

34. The method of claim 32, wherein: The concentration of the catalyst is 1 mol% to 10 mol% relative to the compound represented by the formula (II) or (III).

35. The method according to any one of claims 33 to 34, characterized in that The concentration of the catalyst is 1 mol% to 5 mol% relative to the compound represented by the formula (II) or (III).

36. The method according to any one of claims 31 to 34, characterized in that The acidic aqueous phase contains H2SO4.

37. The method of claim 35, wherein: The acidic aqueous phase contains H2SO4.

38. The method according to any one of claims 31 to 34 and 37, characterized in that The acid concentration in the acidic aqueous phase is between 2M and 5M.

39. The method of claim 35, wherein: The acid concentration in the acidic aqueous phase is between 2M and 5M.

40. The method of claim 36, wherein: The acid concentration in the acidic aqueous phase is between 2M and 5M.

41. The method of claim 31, wherein: Aqueous H2O2 is used in a concentration between 3% and 90% by volume.

42. The method of any one of claims 31 to 34, 37 and 39 to 41, characterized in that The reaction mixture comprises water and does not comprise a water-immiscible organic solvent.

43. The method of claim 35, wherein: The reaction mixture comprises water and does not comprise a water-immiscible organic solvent.

44. The method of claim 36, wherein: The reaction mixture comprises water and does not comprise a water-immiscible organic solvent.

45. The method of claim 38, wherein: The reaction mixture comprises water and does not comprise a water-immiscible organic solvent.

46. ​​The method of any one of claims 31 to 34, 37, 39 to 41 and 43 to 45, characterized in that The reaction is carried out at a temperature ranging from 10°C to 50°C.

47. The method of claim 35, wherein: The reaction is carried out at a temperature ranging from 10°C to 50°C.

48. The method of claim 36, wherein: The reaction is carried out at a temperature ranging from 10°C to 50°C.

49. The method of claim 38, wherein: The reaction is carried out at a temperature ranging from 10°C to 50°C.

50. The method of claim 42, wherein: The reaction is carried out at a temperature ranging from 10°C to 50°C.

51. The method of claim 46, wherein: The reaction is carried out at a temperature ranging from 15°C to 35°C.

52. The method according to any one of claims 47 to 50, characterized in that The reaction is carried out at a temperature ranging from 15°C to 35°C.

53. The method of any one of claims 31 to 34, 37, 39 to 41, 43 to 45 and 47 to 51, characterized in that The catalyst is recycled.

54. The method of claim 35, wherein: The catalyst is recycled.

55. The method of claim 36, wherein: The catalyst is recycled.

56. The method of claim 38, wherein: The catalyst is recycled.

57. The method of claim 42, wherein: The catalyst is recycled.

58. The method of claim 46, wherein: The catalyst is recycled.

59. The method of claim 52, wherein: The catalyst is recycled.

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