DESC:FIELD
The present disclosure relates to a process for the preparation of Ethiprole.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Ethiprole is a non-systemic phenyl-pyrazole insecticide that is effective against a wide range of insects. The structural representation of Ethiprole (i.e. 1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-5-amino-4-(ethylsulfinyl)-1H-pyrazole-3-carbonitrile is given as formula (I) below:

(I)
In insects, Ethiprole acts on the ?-aminobutyric acid-dependent neurotransmission present in the central nervous system. It is effective against a broad spectrum of insects with chewing and sucking mouthparts that tend to damage plants. Ethiprole has a high level of selective toxicity and thus avoids cross-resistance.
Conventional methods for the preparation of Ethiprole provide Ethiprole with impurities. Such methods require further purification of the compound. The impurities in Ethiprole may affect the efficacy, safety, and stability of the final product produced by using Ethiprole. The yield/productivity of Ethiprole obtained from the known processes is considerably low. Further, conventional methods also use ethyl mercaptan, a toxic low boiling liquid with a strongly disagreeable odour. The presence of ethyl mercaptan can be detected by the human nose even in low quantities (as one part in 2.8 billion parts of air, i.e. 0.36 parts per billion). Special equipment and specialized safety precautions are required to handle this toxic compound which is very challenging on a commercial scale.
Therefore, there is felt a need to provide a process for the preparation of Ethiprole that mitigates the aforestated drawbacks or at least provide an alternative solution.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the present disclosure to ameliorate one or more problems of the background or to at least provide a useful alternative.
Another object of the present disclosure is to provide a process for the preparation of Ethiprole.
Yet another object of the present disclosure is to provide a process for the preparation of Ethiprole with comparatively better purity and yield.
Still another object of the present disclosure is to provide a simple and cost-effective process for the preparation of Ethiprole.
Another object of the present disclosure is to provide an environment-friendly and commercially scalable process for the preparation of Ethiprole.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure relates to a process for the preparation of ethiprole. The process comprises reacting a predetermined amount of aminopyrazole with a sulfurizing agent in a first fluid medium at a first predetermined temperature for a first predetermined time period to obtain aminopyrazole disulphide. The aminopyrazole disulphide is reacted with a base, a haloalkane, and a reducing agent in a second fluid medium at a second predetermined temperature for a second predetermined time period to obtain an ethyl thiopyrazole. The so obtained ethyl thiopyrazole is oxidized by using an oxidizing agent in a third fluid medium in the presence of an acid at a third predetermined temperature for a third predetermined time period to obtain ethiprole.
In an embodiment of the present disclosure, the aminopyrazole is 5-amino-1-[2,6-dichloro-4-(trifluoromethylphenyl)-3-cyanopyrazole.
In an embodiment of the present disclosure, the first fluid medium is at least one selected from the group consisting of acetonitrile, methylene dichloride, ethylene dichloride, monochlorobenzene, and toluene.
In an embodiment of the present disclosure, the first fluid medium is at least one selected from the group consisting of acetonitrile, methylene dichloride, ethylene dichloride, monochlorobenzene, and toluene.
In an embodiment of the present disclosure, the first predetermined temperature is in the range of 0°C to 40°C.
In an embodiment of the present disclosure, the first predetermined time period is in the range of 3 hours to 8 hours.
In an embodiment of the present disclosure, the sulfurizing agent is disulphur dichloride.
In an embodiment of the present disclosure, the mole ratio of the sulfurizing agent to the aminopyrazole is in the range of 1:1 to 1:2.
In an embodiment of the present disclosure, the aminopyrazole disulphide 5-amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-3-cyanopyrazole-4-yl-disulphide.
In an embodiment of the present disclosure, the second fluid medium is at least one selected from the group consisting of dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), and sulfolane.
In an embodiment of the present disclosure, the base is at least one selected from the group consisting of potassium carbonate and sodium carbonate.
In an embodiment of the present disclosure, the haloalkane is at least one selected from the group consisting of ethyl bromide and ethyl chloride.
In an embodiment of the present disclosure, the reducing agent is sodium hydroxy methanesulfinate (rongalite).
In an embodiment of the present disclosure, the second predetermined temperature is in the range of 15°C to 30°C.
In an embodiment of the present disclosure, the second predetermined time period is in the range of 3 hours to 8 hours.
In an embodiment of the present disclosure, ethyl thiopyrazole is 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl) 4-(Ethylthio) 1-H pyrazole.
In an embodiment of the present disclosure, the oxidizing agent is at least one selected from the group consisting of hydrogen peroxide, and peracetic acid.
In an embodiment of the present disclosure, the third fluid medium is at least one selected from the group consisting of methanol, ethanol and propanol.
In an embodiment of the present disclosure, the acid is sulfuric acid.
In an embodiment of the present disclosure, the third predetermined temperature is in the range of 40°C to 80°C.
In an embodiment of the present disclosure, the third predetermined time period is in the range of 5 hours to 9 hours.
DETAILED DESCRIPTION
The present disclosure relates to a process for the preparation of Ethiprole.
Embodiments, of the present disclosure, will now be described herein. Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed elements.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer, or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
In insects Ethiprole acts on the ?-aminobutyric acid-dependent neurotransmission system present in the central nervous system. It is effective against a broad spectrum of insects with chewing and sucking mouthparts that tend to damage the plants. Ethiprole has a high level of selective toxicity, and thus avoids cross-resistance.
Conventional methods for the preparation of Ethiprole provide Ethiprole with impurities. Such methods require further purification of the compound. Further, the impurities in Ethiprole may affect the efficacy, safety, and stability of the final product produced by using Ethiprole. The yield/productivity of Ethiprole obtained from the known processes is considerably low.
The present disclosure provides an improved process for the preparation of Ethiprole.
The process of the present disclosure is simple, environment friendly, economical, results in improved yield and higher purity of Ethiprole, and is commercially scalable.
In an aspect of the present disclosure, there is provided a process for preparing
Ethiprole.
The process for preparing Ethiprole comprising the following steps:
I. reacting aminopyrazole with a sulfurizing agent in a first fluid medium at a first predetermined temperature for a first predetermined time period to obtain aminopyrazole disulphide;
II. reacting aminopyrazole disulphide with a base, a haloalkane, and a reducing agent in a second fluid medium at a second predetermined temperature for a second predetermined time period to obtain an ethyl thiopyrazole; and
III. oxidizing ethyl thiopyrazole by using an oxidizing agent in a third fluid medium in the presence of an acid at a third predetermined temperature for a third predetermined time period to obtain ethiprole.
In an embodiment, the process for preparing Ethiprole in accordance with the present disclosure is given in detail below.
In a first step, a predetermined amount of aminopyrazole is mixed with a first fluid medium at a temperature in the range of 20°C to 40° to obtain a solution. To the solution, a predetermined amount of sulfurizing agent is added under stirring to obtain a reaction mixture. The reaction mixture is heated at a first predetermined temperature for a first predetermined time period to obtain a resultant mixture. The resultant mixture is filtered to obtain a wet cake and a filtrate. The wet cake is washed with the first fluid medium and dried to obtain aminopyrazole disulphide. The filtrate is distilled to recover the first fluid medium.
The reaction of sulfurizing agent and aminopyrazole leads to the evolution of hydrogen chloride gas which is neutralized by passing the ammonia gas.
In an embodiment of the present disclosure, the aminopyrazole is 5-amino-1-[2,6-dichloro-4-(trifluoromethylphenyl)-3-cyanopyrazole.
In an embodiment of the present disclosure, the first fluid medium is at least one selected from the group consisting of acetonitrile, methylene dichloride, ethylene dichloride, monochlorobenzene, and toluene. In an exemplary embodiment of the present disclosure, the first fluid medium is acetonitrile.
In an embodiment of the present disclosure, the first predetermined temperature is in the range of 0°C to 40°C. In an exemplary embodiment of the present disclosure, the first predetermined temperature is 20°C.
In an embodiment of the present disclosure, the first predetermined time period is in the range of 3 hours to 8 hours. In an exemplary embodiment of the present disclosure, the first predetermined time period is 4 hours.
In an embodiment of the present disclosure, the sulfurizing agent is disulphur dichloride.
In an embodiment of the present disclosure, the mole ratio of the sulfurizing agent to the aminopyrazole is in the range of 1:1 to 1:2. In an exemplary embodiment of the present disclosure, the mole ratio of the sulfurizing agent to the aminopyrazole is 1:2.
In an embodiment of the present disclosure, the aminopyrazole disulphide 5-amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-3-cyanopyrazole-4-yl-disulphide.
A schematic representation for the preparation of aminopyrazole is given as scheme A, as an exemplary embodiment.

SCHEME A
In a second step, a predetermined amount of aminopyrazole disulphide is mixed with a second fluid medium to obtain a solution. To the solution, a predetermined amount of a base is added to obtain a slurry. A predetermined amount of a haloalkane is added to the slurry to obtain a reaction mass. To the reaction mass, a predetermined amount of a reducing agent and water is added to obtain a product mass. The product mass is maintained at a second predetermined temperature for a second predetermined time period followed by filtering to obtain a wet cake and a mother liquor. The wet cake is washed with the second fluid medium to obtain a washed second fluid medium. The mother liquor and the washed second fluid medium are mixed, and concentrated to obtain a concentrated mass (by removing the second fluid medium).
The concentrated mass is drowned in water to precipitate, to obtain a product mixture. The product mixture is filtered and dried to obtain ethyl thiopyrazole.
In an embodiment of the present disclosure, the second fluid medium is at least one selected from the group consisting of dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), and sulfolane. In an exemplary embodiment of the present disclosure, the second fluid medium is dimethylformamide.
In an embodiment of the present disclosure, the base is at least one selected from the group consisting of potassium carbonate and sodium carbonate. In an exemplary embodiment of the present disclosure, the base is potassium carbonate.
In an embodiment of the present disclosure, the haloalkane is at least one selected from the group consisting of ethyl bromide and ethyl chloride. In an exemplary embodiment of the present disclosure, the haloalkane is ethyl bromide.
In an embodiment of the present disclosure, the reducing agent is sodium hydroxy methanesulfinate (rongalite).
In an embodiment of the present disclosure, the second predetermined temperature is in the range of 15°C to 30°C. In an exemplary embodiment of the present disclosure, the second predetermined temperature is 20°C.
In an embodiment of the present disclosure, the second predetermined time period is in the range of 3 hours to 8 hours. In an exemplary embodiment of the present disclosure, the second predetermined time period is 4 hours.
In an embodiment of the present disclosure, the addition of water accelerates the reaction and increases the yield of the product.
In an embodiment of the present disclosure, the reducing agent and the haloalkane used can be recovered and recycled.
In an embodiment of the present disclosure, ethyl thiopyrazole is 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl) 4-(Ethylthio) 1-H pyrazole.
A schematic representation for the preparation of ethyl thiopyrazole is given as scheme B, as an exemplary embodiment.

SCHEME B
In a final step, a predetermined amount of ethyl thiopyrazole is mixed with a third fluid medium to obtain a solution. A mixture of an acid and the third fluid medium is added to the solution, followed by slowly adding a reducing agent to obtain a reaction mass. The reaction mass is heated to a third predetermined temperature for a third predetermined time period to obtain a resultant mass. The resultant mass was filtered to obtain a wet cake. The wet cake is washed with water followed by drying to obtain a crude ethiprole. The crude ethiprole is crystallized in the third fluid medium to obtain a pure ethiprole.
In an embodiment of the present disclosure, the oxidizing agent is at least one selected from the group consisting of hydrogen peroxide, and peracetic acid. In an exemplary embodiment of the present disclosure, the oxidizing agent is hydrogen peroxide.
In an embodiment of the present disclosure, the third fluid medium is at least one selected from the group consisting of methanol, ethanol and propanol. In an exemplary embodiment of the present disclosure, the third fluid medium is methanol.
In an embodiment of the present disclosure, the acid is sulfuric acid.
In an embodiment of the present disclosure, the third predetermined temperature is in the range of 40°C to 80°C. In an exemplary embodiment of the present disclosure, the third predetermined temperature is 60°C.
In an embodiment of the present disclosure, the third predetermined time period is in the range of 5 hours to 9 hours. In an exemplary embodiment of the present disclosure, the third predetermined time period is 6 hours.
A schematic representation for the preparation of ethiprole is given as scheme C, as an exemplary embodiment.

In an embodiment of the present disclosure, the ethiprole has a purity of >95%.
The present disclosure provides a simple, economic, and safe process without the use of Ethyl mercaptan, a highly toxic compound, for the preparation of ethiprole which provides a comparatively higher yield of the product with greater purity.
The foregoing description of the embodiments has been provided for purposes of illustration and is not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
The present disclosure is further described in light of the following experiments which are set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure. The following experiments are scalable to industrial/commercial process.
EXPERIMENTAL DETAILS
EXAMPLE 1: Preparation of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl) pyrazole-4-yl disulphide (Aminopyrazole disulphide):
321 g (1.0 mole) of 5-amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-3-cyanopyrazole was added to 1000 ml of acetonitrile at 30°C to obtain a solution. The solution was cooled to 0°C followed by rapidly adding 67.5g (0.5 mole) of disulphur dimonochloride over 5 minutes to obtain a reaction mixture. The temperature of the reaction mixture was increased to 10°C due to the exothermicity of the reaction. The reaction mixture was then heated to 20°C and maintained at 20°C for 4 hrs. After completion of the reaction, Nitrogen gas was purged into the reaction mixture to drive off HCl gas. Further, ammonia gas was passed into the reaction mixture at 20°C to bring the pH to 6.0 to 7.0 to obtain a resultant mixture. The resultant mixture was then filtered to obtain a cake followed by washing of the cake with acetonitrile. The cake (after washing with acetonitrile) was then slurried in water to dissolve the formed ammonium chloride (inorganics), then filtered and dried at <100°C to obtain 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl) pyrazole-4-yl disulphide.
The yield of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl) pyrazole-4-yl disulphide was 93% and the purity was >99.0%.
EXAMPLE 2: Preparation of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl) 4-(Ethylthio) 1-H pyrazole (Ethyl thiopyrazole):
352 g (0.5 mole) of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl) pyrazole-4-yl disulphide was added to 2500 ml of DMF at 20°C to obtain a clear solution. 138g (1.0 mole) of potassium carbonate was added to the clear solution and equilibrated for 15 minutes to obtain a slurry. 120 g (1.1 mole) of ethyl bromide was added to the slurry at 20°C to obtain a reaction mass. The reaction mass was then cooled to 15°C and equilibrated for 30 minutes followed by rapidly adding 154 g of sodium hydroxy methanesulfinate (Rongalite C, 1.0 mole as 75% to 77% pure) and then 1 ml of water to obtain a product mass. The product mass was maintained at 20°C for 4 hrs followed by filtration of the inorganic salt to obtain a wet cake and a mother liquor. The wet cake was washed with DMF. The mother liquor and the washes were mixed and concentrated to remove DMF to obtain a concentrated mass.
The concentrated mass was then drowned into the water to precipitate out the product. The product was filtered, washed with 1000 ml of water, and dried at <100°C to obtain 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl) 4-(Ethylthio) 1-H pyrazole.
The yield of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl) 4-(Ethylthio) 1-H pyrazole was 92% and the purity was >97% purity.
EXAMPLE 3: Preparation of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl) -4-(Ethylsulfinyl) 1-H pyrazole (Ethiprole):

381 g (1.0 mole) of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl)-4-(Ethylthio) 1-H pyrazole was added to 900ml of MeOH at 30°C to obtain a clear solution. A mixture of 5.0g of 98% H2SO4 in 100ml of MeOH was added to the clear solution followed by slow addition of 136 g (1.2mole as 30%) of H2O2 solution at 30°C to obtain a reaction mass. The reaction mass was then heated slowly to 60°C. Solids precipitation was observed on attaining 60°C. Further, the reaction mass was maintained at 60°C for 6 hrs to obtain a resultant mixture. The resultant mixture was then cooled to 30°C followed by the addition of sodium bisulphite to destroy the excess H2O2. Further, sodium bicarbonate was added to neutralize the H2SO4 to obtain a mass. The mass was then filtered to obtain a cake. The cake was washed with water to remove the inorganic salt and dried to obtain a crude ethiprole. The crude ethiprole was then crystallized by using MeOH to obtain ethiprole.
The yield of ethiprole was 82% and the purity was >95%.
TECHNICAL ADVANCEMENT
The present disclosure described hereinabove has several technical advantages including, but not limited to, the realization of a process for the preparation of ethiprole (i.e., 1-(2,6-dichloro-4-trifluoromethyl)phenyl)-5-amino-4-ethylsulfinyl) -1H-pyrazole-3-carbonitrile) that
• enables to recover fluid medium (solvents) and reducing agent, hence economical;
• is simple and environment friendly; and
• provides ethiprole having comparatively high purity and high yield.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results. While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Variations or modifications to the formulation of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this invention.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values given for various physical parameters, dimensions, and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions, and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary.
While considerable emphasis has been placed herein on the specific features of the preferred embodiment, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiment without departing from the principles of the disclosure. These and other changes in the preferred embodiment of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.
,CLAIMS:WE CLAIM:
1. A process for preparing ethiprole, said process comprising the following steps:
a. reacting a predetermined amount of aminopyrazole with a sulfurizing agent in a first fluid medium at a first predetermined temperature for a first predetermined time period to obtain aminopyrazole disulphide;
b. reacting said aminopyrazole disulphide with a base, a haloalkane, and a reducing agent in a second fluid medium at a second predetermined temperature for a second predetermined time period to obtain an ethyl thiopyrazole; and
c. oxidizing said ethyl thiopyrazole by using an oxidizing agent in a third fluid medium in the presence of an acid at a third predetermined temperature for a third predetermined time period to obtain ethiprole.
2. The process as claimed in claim 1, wherein said aminopyrazole is 5-amino-1-[2,6-dichloro-4-(trifluoromethylphenyl)-3-cyanopyrazole.
3. The process as claimed in claim 1, wherein said first fluid medium is at least one selected from the group consisting of acetonitrile, methylene dichloride, ethylene dichloride, monochlorobenzene, and toluene.
4. The process as claimed in claim 1, wherein said first predetermined temperature is in the range of 0°C to 40°C.
5. The process as claimed in claim 1, wherein said first predetermined time period is in the range of 3 hours to 8 hours.
6. The process as claimed in claim 1, wherein said sulfurizing agent is disulphur dichloride.
7. The process as claimed in claim 1, wherein said aminopyrazole disulphide is 5-amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-3-cyanopyrazole-4-yl-disulphide.
8. The process as claimed in claim 1, wherein said base is at least one selected from the group consisting of potassium carbonate, and sodium carbonate.
9. The process as claimed in claim 1, wherein said haloalkane is at least one selected from the group consisting of ethyl bromide, and ethyl chloride.
10. The process as claimed in claim 1, wherein said reducing agent is sodium hydroxy methanesulfinate.
11. The process as claimed in claim 1, wherein said second fluid medium is at least one selected from the group consisting of dimethylformamide (DMF), N,N-dimethylacetamide (DMAc) and sulfolane.
12. The process as claimed in claim 1, wherein said second predetermined temperature is in the range of 15°C to 30°C.
13. The process as claimed in claim 1, wherein said second predetermined time period is in the range of 3 hours to 8 hours.
14. The process as claimed in claim 1, wherein said ethyl thiopyrazole is 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl) 4-(Ethylthio) 1-H pyrazole.
15. The process as claimed in claim 1, wherein said oxidizing agent is at least one selected from the group consisting of hydrogen peroxide, and peracetic acid.
16. The process as claimed in claim 1, wherein said third fluid medium is at least one selected from the group consisting of methanol, ethanol and propanol.
17. The process as claimed in claim 1, wherein said acid is sulfuric acid.
18. The process as claimed in claim 1, wherein said third predetermined temperature is in the range of 40°C to 80°C.
19. The process as claimed in claim 1, wherein said third predetermined time period is in the range of 5 hours to 9 hours.
20. The process as claimed in claim 1, wherein mole ratio of said sulfurizing agent to said aminopyrazole is in the range of 1:1 to 1:2.

Dated this 23rd day of August, 2023

_______________________________
MOHAN RAJKUMAR DEWAN, IN/PA – 25
of R.K. DEWAN & CO.
Authorized Agent of Applicant

TO,
THE CONTROLLER OF PATENTS
THE PATENT OFFICE, AT MUMBAI