WO2022162447A1

WO2022162447A1 - Processes for preparation of chlorantraniliprole or a salt or its intermediates thereof

Info

Publication number: WO2022162447A1
Application number: PCT/IB2021/057708
Authority: WO
Inventors: Srinivas Simhadri; Nagaraju MEKALA; Srinivasa Rao BUDDEPU; Karunakara Rao Javvaji; Chiranjeevi CHEEKATI; Srinivasa Rao Lagadapati; Prabhakar Marri; Uma Maheswer Rao VASIREDDI
Original assignee: Laurus Labs Limited
Priority date: 2021-01-27
Filing date: 2021-08-23
Publication date: 2022-08-04

Abstract

The present invention generally relates to a process for preparation of chlorantraniliprole or a salt thereof. Further, the present invention relates to an improved process for preparation of intermediate of chlorantraniliprole.

Description

“PROCESSES FOR PREPARATION OF CHLORANTRANILIPROLE OR A SALT OR ITS INTERMEDIATES THEREOF”

PRIORITY:

This application claims the benefit under Indian Provisional Application No.(S) 202141003552 filed on 27 Jan, 2021 entitled “Process for preparation of chlorantraniliprole or a salt thereof’; 202141003553 filed on 27 Jan, 2021 entitled “An improved process for preparation of chlorantraniliprole or a salt thereof’ and 202141035921 filed on 09 Aug, 2021 entitled “An improved process for preparation of 2-amino-5-chloro-N-3-dimethyl benzamide” the contents of each of which are incorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates to processes for preparation of chlorantraniliprole or a salt thereof. Further, the present invention relates to an improved process for preparation of intermediate of chlorantraniliprole.

BACKGROUND OF THE INVENTION

Chlorantraniliprole is a class of anthranilic-diamide insecticide derivative compounds and is chemically known as 3-Bromo-N-[4-chloro-2-methyl-6-(methyl carbamoyl) phenyl]-l-(3-chloro-2-pyridine-2-yl)-lH-pyrazole-5-carboxamide, it has the following structure:

Chlorantraniliprole (Formula I)

Chlorantraniliprole is being developed world-wide by DuPont belonging to a new class of selective insecticides featuring a novel mode of action to control a range of pests belonging to the order Lepidoptera and some other Coleoptera, Diptera and Isoptera species. Preparation of chlorantraniliprole was disclosed in different patent publications; for example, PCT application Number: 2003/015519 (“the ‘519 publication”) disclosed process to prepare chlorantraniliprole by the following scheme:

PCT application Number: 2004/111030 (“the ‘030 publication”) discloses an alternative process for preparation of chlorantraniliprole. The ‘030 publication disclosed process is as follows:

PCT application Number: 2006/062978 (“the ‘978 publication”) discloses an alternative process for preparation of chlorantraniliprole, as follows:

PCT application Number: 2019/207595 (“the ‘595 publication”) discloses an alternative process for preparation of chlorantraniliprole, as follows:

Chlorantraniliprole All the above reported process of chlorantraniliprole involves expensive raw materials and involves formation of impurities with low yields and purity.

Further, the ‘978 publication discloses a process for preparation of compound of Formula V, as follows:

Compound of Formula V is the key intermediate and main cost contributor in the preparation of chlorantraniliprole. The ‘978 application disclosed preparation of compound of Formula V in three stage process from 2-amino-3-methyl benzoic acid of Formula Al and the process involves isolation of intermediate products of Formula All and Formula AIII as solid, which makes the process lengthy as it involves multiple steps of solvent extractions, isolation and drying steps and this leads to low yield of the Formula V from the starting compound of Formula Al. The ‘978 process also involves use of hydrogen peroxide in oxy-chlorination, which is not viable on large scale manufacturing as it extremely shock-sensitive explosives and require special care while handling.

Further other known literatures for ex: CN103539694B, CN111134128A, CN103109816B and Nongyao (2013), 52(11), 793-795, 811 discloses preparation of this compound of Formula V but all the literatures involves the same processing strategies, isolation of intermediates as mentioned under the ‘978 publication.

Chlorantraniliprole is one of the important insecticide available in the market. As all the reported processes involves isolation of each intermediate products of Formula All and Formula AIII as solid in the preparation of Formula V, which involves increasing the reactor occupancy and additional process steps such as use of multiple solvent systems for each stage, isolation of each stage by filtration, drying and testing of each intermediate; hence, the reported processes requires excess reactor occupancy and excess manufacturing time and this creates extra burden to the final cost of the material. As disclosed above, compound of Formula V is the key cost contributor in the preparation of chlorantraniliprole and to reduce the manufacturing cost of the chlorantraniliprole it is desirable to reduce the manufacturing cost of the intermediates involved in the process.

Hence, it’s important to develop a simple and cost effective improved process for preparation of pure chlorantraniliprole or its intermediates with avoiding the aforementioned problems and with high yield, which is readily amenable to large scale production and free from its impurities.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides processes for preparation of chlorantraniliprole or a salt thereof of Formula I. The present invention also relates to an improved process for preparation of chlorantraniliprole or a salt thereof without isolating the intermediates.

In accordance with one embodiment, the present invention provides a process for preparation of chlorantraniliprole of Formula I, comprising:

a) reacting a compound of Formula III; wherein “R” is selected from straight or branched chain Ci-6 alkyl group, with a compound of Formula IV in presence of a suitable activating agent, a suitable base and a suitable solvent to obtain a compound of Formula II, wherein “R” is selected from straight or branched chain Ci-6 alkyl group; and

b) reacting the compound of Formula II with a source of monomethylamine to obtain chlorantraniliprole.

In accordance with another embodiment, the present invention provides a process for preparation of chlorantraniliprole of Formula I, comprising: a) reacting a compound of Formula III; wherein “R” is selected from straight or branched chain Ci-6 alkyl group, with a compound of Formula IV in presence of a suitable activating agent, a suitable base and a suitable solvent to obtain a compound of Formula II, wherein “R” is selected from straight or branched chain Ci-6 alkyl group; and b) reacting the compound of Formula II with a source of monomethylamine to obtain chlorantraniliprole; wherein the compound of Formula II is not isolated as a solid.

In accordance with another embodiment, the present invention provides a process for preparation of chlorantraniliprole of Formula I, comprising: a) reacting a compound of Formula III; wherein “R” is selected from straight or branched chain Ci-6 alkyl group, with a compound of Formula IV in presence of a suitable activating agent, a suitable base and a suitable solvent to obtain a solution containing compound of Formula II, wherein “R” is selected from straight or branched chain Ci-6 alkyl group; and b) adding a source of monomethylamine to the step a) to obtain chlorantraniliprole.

In accordance with another embodiment, the present invention provides a process for preparation of chlorantraniliprole of Formula I, comprising: a) reacting a compound of Formula III; wherein “R” is selected from straight or branched chain Ci-6 alkyl group, with a compound of Formula IV in presence of a suitable activating agent, a suitable base and a suitable solvent at a temperature of about 25°C to reflux temperature, b) cooling the step a) solution to below 25°C, c) adding a source of monomethylamine to the step b) solution, d) heating the step c) to about 25°C to reflux temperature, e) concentrating the step d) reaction mass to obtain a solid compound, f) adding a suitable organic solvent to the step e) and heating to reflux temperature, g) cooling the solution to below 35°C, and h) filtering the chlorantraniliprole.

In accordance with another embodiment, the present invention provides an improved process for preparation of a compound of Formula IV, comprising:

a) mixing a suitable oxidizing agent, a suitable acid and a suitable organic solvent, b) heating the reaction mass to about 40°C to reflux temperature, c) adding a compound of Formula VII to the above step b) reaction mass,

Formula VII d) isolating the compound of Formula VI; wherein “R” is selected from straight or branched chain Ci-6 alkyl group, and

e) hydrolyzing the compound of formula VI, wherein “R” is selected from straight or branched chain Ci-6 alkyl group to obtain a compound of Formula IV.

In accordance with another embodiment, the present invention provides a process for preparation of chlorantraniliprole of Formula I, comprising: a) mixing a suitable oxidizing agent, a suitable acid and a suitable organic solvent b) heating the reaction mass to about 40°C to reflux temperature, c) adding a compound of Formula VII, wherein “R” is selected from straight or branched chain Ci-6 alkyl group, to the above step b) reaction mass

Formula VII d) isolating the compound of Formula VI; wherein “R” is selected from straight or branched chain Ci-6 alkyl group

Formula VI e) hydrolyzing the compound of formula VI, wherein “R” is selected from straight or branched chain Ci-6 alkyl group to obtain a compound of Formula IV; f) reacting the compound of Formula IV with a compound of Formula III; wherein “R” is selected from straight or branched chain Ci-6 alkyl group, in presence of a suitable activating agent, a suitable base and a suitable solvent at a temperature of about 25°C to reflux temperature, g) cooling the step f) solution to below 25°C, h) adding a source of monomethylamine to the step g) solution, i) heating the step h) to about 25°C to reflux temperature, j) concentrating the step i) reaction mass to obtain a solid compound, k) adding a suitable organic solvent to the step j) and heating to reflux temperature, l) cooling the solution to below 35°C, and m) filtering the chlorantraniliprole.

In accordance with another embodiment, the present invention provides a process for preparation of chlorantraniliprole of Formula I, comprising: reacting a compound of Formula II; wherein “R” is selected from straight or branched chain Ci-6 alkyl group, with a source of monomethylamine in a suitable solvent to obtain chlorantraniliprole. In accordance with another embodiment, the present invention provides a process for preparation of chlorantraniliprole of Formula I, comprising: a) reacting a compound of Formula III; wherein “R” is methyl, with a compound of Formula IV in presence of a suitable activating agent, a suitable base and a suitable solvent to obtain a compound of Formula II, wherein “R” is methyl; and b) reacting the compound of Formula II, wherein “R” is methyl with a source of monomethylamine to obtain chlorantraniliprole; wherein the compound of Formula II is not isolated as a solid.

In accordance with another embodiment, the present invention provides an improved process for preparation of chlorantraniliprole of Formula I,

comprising: reacting a compound of Formula V with a compound of Formula VI; wherein “R” is selected from straight or branched chain Ci-6 alkyl group, in presence of a suitable base and a suitable solvent to obtain chlorantraniliprole.

In accordance with another embodiment, the present invention provides an improved process for preparation of chlorantraniliprole of Formula I, comprising: reacting a compound of Formula V with a compound of Formula VI; wherein “R” is ethyl, in presence of a suitable base and a suitable solvent to obtain chlorantraniliprole.

a) mixing a suitable oxidizing agent, a suitable acid and a suitable organic solvent b) heating the reaction mass to about 40°C to reflux temperature, c) adding a compound of Formula VII, wherein “R” is selected from straight or branched chain Ci-6 alkyl group, to the above step b) reaction mass,

Formula VI e) reacting a compound of Formula VI; wherein “R” is selected from straight or branched chain Ci-6 alkyl group, with a compound of Formula V in presence of a suitable base and a suitable solvent to obtain chlorantraniliprole.

In accordance another embodiment, the present invention provides an improved process for preparation of compound of Formula V, comprising:

Formula V a) reacting a compound of Formula Al with a phosgene or its derivative and a suitable base in a suitable solvent to obtain a compound of Formula All,

Formula Al Formula All b) reacting the compound of Formula All with a source of monomethyl amine to obtain a compound of Formula AIII, and

Formula AIII c) reacting the compound of Formula AIII with a source of chloride to obtain a compound of Formula V; wherein the step a) to c) are carried out in one-pot reaction without isolating the intermediate compound of Formula All and Formula AIII as solid.

In accordance another embodiment, the present invention provides an improved process for preparation of compound of Formula V, comprising: a) reacting a compound of Formula Al with a phosgene or its derivative and a suitable inorganic base in a suitable solvent to obtain a compound of Formula All, b) reacting the compound of Formula All with a source of monomethyl amine to obtain a compound of Formula AIII, and c) reacting the compound of Formula AIII with a source of chloride to obtain a compound of Formula V; wherein the step a) to c) are carried out in one -pot reaction without isolating the intermediate compound of Formula All and Formula AIII as solid.

In accordance with another embodiment, the present invention provides an improved process for preparation of compound of Formula V, comprising: a) reacting a compound of Formula Al with a phosgene or its derivative and a suitable base in a suitable solvent to obtain a solution of compound of Formula All, b) adding a source of monomethyl amine to the solution of compound of Formula All to obtain a solution of compound of Formula AIII, c) adding a source of chloride to the solution of compound of Formula AIII to obtain a compound of Formula V ; and d) isolating the compound of Formula V.

In accordance with another embodiment, the present invention provides an improved process for preparation of compound of Formula V, comprising: a) reacting a compound of Formula Al with a phosgene or its derivative and a suitable base in a suitable solvent to obtain a solution containing compound of Formula All, b) adding a source of monomethyl amine to the solution of step a) to obtain a containing compound of Formula AIII, c) adding a source of chloride to the solution of step b) to obtain a solution of containing compound of Formula V, d) adding water and a suitable acid to the step c) solution, e) separating the organic and aqueous layers, f) adding a suitable base to the aqueous layer, and g) filtering the compound of Formula V.

In accordance with another embodiment, the present invention provides an improved process for preparation of compound of Formula V having less than 0.5% by HPLC of at least one of impurities at RRT-0.31, RRT-0.53, RRT-0.79, RRT-0.89, RRT-1.06, RRT-1.84, RRT-2.01, RRT-2.03, RRT-2.62, RRT-2.96, RRT-3.08 and RRT-3.11, comprising: a) reacting a compound of Formula AIII with a source of chloride to obtain a solution containing compound of Formula V having more than 0.5% by HPLC of at least one of impurities at RRT-0.31, RRT-0.53, RRT-0.79, RRT-0.89, RRT-1.06, RRT-1.84, RRT-2.01, RRT-2.03, RRT-2.62, RRT-2.96, RRT-3.08 and RRT-3.11, b) adding water and a suitable acid to the step a) solution, c) separating the organic and aqueous layers, d) adding a suitable base to the aqueous layer, and e) filtering the compound of Formula V.

In accordance with another embodiment, the present invention provides an improved process for preparation of chlorantraniliprole , comprising:

a) preparing a compound of Formula V according processes described as above embodiments, and b) converting the compound of Formula V in to chlorantraniliprole.

In accordance with another embodiment, the present invention provides a compound of Formula V having less than 0.5% by HPLC of at least one of impurities at RRT-0.31, RRT-0.53, RRT-0.79, RRT-0.89, RRT-1.06, RRT-1.84, RRT-2.01, RRT-2.03, RRT- 2.62, RRT-2.96, RRT-3.08 and RRT-3.11.

In accordance with another embodiment, the present invention provides crystalline chlorantraniliprole characterized by a powder X-ray diffraction (PXRD) pattern substantially in accordance with Figure 1. In accordance with another embodiment, the present invention provides crystalline chlorantraniliprole characterized by X-Ray diffraction (XRD) pattern having at least one peak selected from at about 8.6, 10.0, 10.5, 10.6, 11.4, 11.7, 12.2, 14.0, 14.2, 14.4, 14.6, 14.9, 15.6, 16.1, 16.6, 17.3, 17.5, 17.8, 18.3, 18.5, 20.0, 20.3, 20.5, 20.7, 21.1, 21.2, 21.4, 21.5, 21.7, 22.7, 22.9, 23.4, 24.3, 24.7, 24.9, 25.3, 25.6, 26.1, 27.2, 27.5, 28.4, 29.0, 29.2, 29.4, 29.8, 30.0 and 30.3 ±0.2° 20.

In accordance with another embodiment, the present invention provides a crystalline compound of Formula Ila characterized by a powder X-ray diffraction (PXRD) pattern substantially in accordance with Figure 2.

In accordance with another embodiment, the present invention provides a crystalline compound of Formula Ila characterized by X-Ray diffraction (XRD) pattern having at least one peak selected from at about 6.8, 8.2, 9.3, 10.1, 11.1, 12.4, 12.8, 13.5, 14.3, 14.8, 15.6, 15.7, 15.9, 16.5, 18.1, 18.7, 19.0, 19.5, 19.9, 20.4, 20.9, 21.7, 22.0, 22.5, 22.7, 23.2, 23.5, 24.0, 24.3, 24.8, 25.3, 25.9, 26.4, 27.2, 27.7, 27.9, 28.3, 28.9, 29.1, 29.2, 29.8 and 30.5 ±0.2° 20.

In accordance with another embodiment, the present invention provides a composition comprising chlorantraniliprole, prepared by the process of the present invention and/or at least one excipient.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention.

Figure 1 is the characteristic powder X-ray diffraction (PXRD) pattern of chlorantraniliprole prepared according to Example- 1.

Figure 2 is the characteristic powder X-ray diffraction (PXRD) pattern of Formula Ila prepared according to Example -4. DETAILED DESCRIPTION OF THE INVENTION

The present invention encompasses processes for preparation of chlorantraniliprole of Formula I. The present invention also relates to an improved process for preparation of chlorantraniliprole or a salt thereof without isolating compound of Formula II.

Unless otherwise specified the term “straight or branched chain Ci-6 alkyl” used herein is selected from but not limited to methyl, ethyl, propyl, isopropyl, butyl, iso-butyl, tertbutyl, pentyl, iso-pentyl, hexyl, iso-hexyl, iso-amyl and the like. Optionally the straight or branched chain Ci-6 alkyl may be further substituted with a suitable substituent, which may be selected from the group comprising halogen, aryl and the like; preferably methyl, ethyl or iso-butyl; more preferably methyl or ethyl. The term "one -pot reaction" as used in this application means a process uses a strategy to improve the efficiency of a chemical reaction whereby a reactant is subjected to successive chemical reactions in just one solvent/reactor. This is much desired by chemists because avoiding a lengthy separation process and purification of the intermediate chemical compounds can save time and resources, improves the efficiency of a chemical reaction, and offers better chemical yield.

The starting materials, a compound of Formula III and Formula IV are known in the art and can be produced by methods known and recognized by the organic chemist of ordinary skill in the art, for example US9301529 and US7232836. Alternatively Formula IV can also be prepared by the procedure as described by the following embodiments of the invention.

The step a) of forgoing process involves reaction of a compound of Formula III with a compound of Formula IV in presence of a suitable activating agent, a suitable base and a suitable solvent to obtain a compound of Formula II in a solution.

In a preferred embodiment the exemplary compound of Formula III and Formula II can be represented as follows:

The suitable activating agent used in aforementioned step a) is selected from the group consisting of but not limited to acid-chloride reagents such as thionyl chloride, pivaloyl chloride and the like, sulfonyl-chloride reagents such as methane sulfonyl chloride, ethane sulfonyl chloride, benzene sulfonyl chloride, p-toluene sulfonyl chloride, p-nitro sulfonyl chloride and the like, coupling agents such as carbonyldiimidazole (CDI), diisopropylcarbodiimide (DCI), N-(3-dimethylaminopropyl)-N’ -ethyl carbodiimide (EDC), dicyclohexyl carbodiimide (DCC), propanephosphonic acid cyclic anhydride (PPA), benzotriazol- 1-yl-oxytripyrrolidino phosphonium hexafluorophosphate

(PyBOP), bromo- tripyrrolidino- phosphonium hexafluorophosphate (PyBrOP), benzotriazol- 1-yloxy-tris (dimethylamino)-phosphonium hexafluorophosphate (BOP), Propylphosphonic anhydride (T3P), 2-(7-aza-lH-benzotriazol-l-yl)- N,N,N’,N’ -tetra methylaminium hexafluorophosphate) (HATU), (l-cyano-2-ethoxy-2-oxoethyl idenarninooxy)dirnethylamino-morpholino-carberiiurn hexa fluorophosphate (COMU), N,N,N',N'-Tetramethyl-O-(lH-benzotriazol-l-yl)uronium hexafluoro phosphate, O- (benzotriazol-l-yl)-N,N,N',N'-tetramethyluronium hexafluoro phosphate (HBTU), 2- (lH-Benzotriazol-l-yl)-N,N,N’,N’-tetramethylaminium tetrafluoroborate (TBTU) and the like and mixture thereof; preferably pivaloyl chloride, methane sulfonyl chloride or carbonyldiimidazole; more preferably methane sulfonyl chloride.

The suitable base used in aforementioned step a) is selected from the group consisting of but not limited to inorganic bases selected from alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide and the like; alkali metal alkoxides such as sodium methoxide, sodium ethoxide, sodium tert-butoxide, potassium tert-butoxide and the like; alkali metal carbonates such as sodium carbonate, potassium carbonate, cesium carbonate and the like; alkali metal bicarbonates such as sodium bicarbonate, potassium bicarbonate and the like; organic bases selected from the group comprising of triethylamine, isopropyl ethylamine, diisopropyl amine, diisopropyl ethylamine, N-methyl morpholine, piperidine, pyridine, 2-picoline, 3-picoline and the like and mixtures thereof; preferably sodium hydroxide, sodium methoxide, triethylamine, diisopropyl ethylamine or 3-picoline; more preferably 3-picoline.

The suitable solvent used in aforementioned step a) is selected from the group consisting of but not limited to amides, sulfoxides, ketones, nitriles, ethers, halogenated hydrocarbons, aromatic hydrocarbons and the like and mixtures thereof. The amides include, but are not limited to dimethylacetamide, dimethylformamide, N- methylpyrrolidone and the like and mixtures thereof; sulfoxides include, but are not limited to dimethyl sulfoxide, diethyl sulfoxide and the like and mixtures thereof; ketones include, but are not limited to acetone, methyl isobutyl ketone, methyl ethyl ketone and the like; nitriles include, but are not limited to acetonitrile, propionitrile and the like; ethers include, but are not limited to tetrahydrofuran, methyl tetrahydrofuran, dimethyl ether, diisopropyl ether, methyl tertiary butyl ether, 1,4-dioxane and the like; halogenated hydrocarbons include, but are not limited to methylene chloride, ethylene chloride, chloroform and the like; aromatic hydrocarbons include, but are not limited to toluene, xylene and the like and mixture thereof; preferably acetonitrile, tetrahydrofuran or methylene chloride; more preferably acetonitrile or methylene chloride.

The reaction of a Formula III with a compound of Formula IV is carried out at a temperature of about 25°C to reflux temperature; preferably at about 25°C to about 35°C.

After completion of the step a) reaction, the resultant compound of Formula II may be isolated as a solid or may be insitu converted to chlorantraniliprole without isolating the compound of Formula II as a solid by directly adding a source of monomethylamine to the step a) solution.

In a preferred embodiment, after completion of the step a) reaction, optionally the obtained compound of Formula II can be isolated from step a) reaction mass by conventional techniques such as precipitation by cooling the reaction mass, isolated by solvent precipitation, crystallization, concentrated by subjecting the solution to heating, decantation or filtration; preferably if isolation involves compound of Formula II can be isolated by precipitation by adding a suitable solvent such as water, and proceed for step b) reaction.

In another preferred embodiment, after completion of the step a) reaction the step b) reaction is carried out in a one pot reaction without isolating the compound of formula II as solid. The reaction includes an optional step of washing the organic layer obtained from the step a) with water and separating the product containing organic layer and to this source of monomethylamine may be added.

The source of monomethylamine used in aforementioned step b) is selected from the group consisting aqueous methyl amine, methyl amine in a solvent, methyl amine gas and the like; preferably aqueous methyl amine or methyl amine gas.

Advantageously, source of monomethylamine may be added to the reaction mass by cooling the reaction mass temperature to below 25°C; preferably at 0-5°C and then the reaction of a Formula II with a source of monomethylamine is carried out at a temperature of about 25°C to reflux temperature; preferably at about 30°C to about 40°C. Optionally the step b) is carried out in presence of a suitable base. The suitable base optionally used in aforementioned step b) is selected from the group consisting of but not limited to inorganic bases selected from alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide and the like; alkali metal alkoxides such as sodium methoxide, sodium ethoxide, sodium tert-butoxide, potassium tert- butoxide and the like; alkali metal carbonates such as sodium carbonate, potassium carbonate, cesium carbonate and the like; alkali metal bicarbonates such as sodium bicarbonate, potassium bicarbonate and the like; organic bases selected from the group comprising of triethylamine, isopropyl ethylamine, diisopropyl amine, diisopropyl ethylamine, N-methyl morpholine, piperidine, pyridine, 2-picoline, 3-picoline and the like and mixtures thereof.

In another embodiment, if the forgoing process involves isolation of compound of Formula II after step a), then the step b) reaction may be optionally carried out in presence of a suitable solvent, wherein the solvent is selected from the group consisting of but not limited to alcohols, amides, sulfoxides, ketones, nitriles, ethers, halogenated hydrocarbons, aromatic hydrocarbons, water and mixtures thereof. The alcohols include, but are not limited to methanol, ethanol, butanol, pentanol, isopropanol, isopentanol and the like and mixtures thereof; amides include, but are not limited to dimethylacetamide, dimethylformamide, N-methylpyrrolidone and the like and mixtures thereof; sulfoxides include, but are not limited to dimethyl sulfoxide, diethyl sulfoxide and the like and mixtures thereof; ketones include, but are not limited to acetone, methyl isobutyl ketone, methyl ethyl ketone and the like; nitriles include, but are not limited to acetonitrile, propionitrile and the like; ethers include, but are not limited to tetrahydrofuran, methyl tetrahydrofuran, dimethyl ether, diisopropyl ether, methyl tertiary butyl ether, 1,4-dioxane and the like; halogenated hydrocarbons include, but are not limited to methylene chloride, ethylene chloride, chloroform and the like; aromatic hydrocarbons include, but are not limited to toluene, xylene and the like; preferably acetonitrile, tetrahydrofuran or methylene chloride; more preferably acetonitrile or methylene chloride.

After completion of the step b) reaction, the resultant chlorantraniliprole can be isolated by conventional techniques such as precipitation by cooling the reaction mass, isolated by solvent precipitation, crystallization, concentrated by subjecting the solution to heating, decantation or filtration; preferably isolated by precipitation by adding a suitable solvent such as water and then filtering the product or complete concentrating of the solvent by subjecting the solution to heating followed by isolating the product from another solvent such as methanol or acetone.

Then the chlorantraniliprole obtained by the process described as above may optionally be stirred with a suitable organic solvent at a temperature of about 25°C to about reflux temperature. The organic solvent used herein is selected from the group consisting of but not limited to alcohols, ketones, ethers, alicyclic hydrocarbons, water and mixtures thereof. The alcohols include, but are not limited to methanol, ethanol, butanol, pentanol, isopropanol, isopentanol and the like and mixtures thereof; ketones include, but are not limited to acetone, methyl isobutyl ketone, methyl ethyl ketone and the like; ethers include, but are not limited to tetrahydrofuran, methyl tetrahydrofuran, dimethyl ether, diisopropyl ether, methyl tertiary butyl ether, 1,4-dioxane and the like; alicyclic hydrocarbons include, but are not limited to cyclopropane, cyclobutane, cyclopentane, cyclohexane, methyl cyclohexane, cycloheptane, cyclooctane and the like and mixture thereof; preferably methanol, acetone, methyl tetrahydrofuran or cyclohexane; more preferably methanol or acetone.

Then the resultant chlorantraniliprole can be isolated by conventional techniques such as precipitation by cooling the reaction mass, isolated by solvent precipitation, crystallization, concentrated by subjecting the solution to heating, decantation or filtration; preferably precipitation by cooling the reaction mass to below 30°C. The resultant product may optionally be further dried at a temperature of about 35°C to about 85°C for sufficient period of time. Drying can be suitably carried out in a tray dryer, vacuum oven, air oven and the like; preferably drying is carried out under vacuum at a temperature of about 45°C to about 75°C for sufficient period of time.

In another embodiment, the present invention provides an improved process for preparation of chlorantraniliprole of Formula I,

The starting materials, a compound of Formula V and Formula VI are known in the art and can be produced by methods known and recognized by the organic chemist of ordinary skill in the art, for example US7232836. Alternatively Formula VI can also be prepared by the procedure as described by the following embodiments of the invention.

In a preferred embodiment the exemplary compound of Formula VI can be represented as follows:

The base used for reaction of compound of Formula V with a compound of Formula VI is selected from silyl bases such as Lithium bis(trimethylsilyl)amide, Sodium bis(trimethylsilyl)amide, Potassium bis(trimethylsilyl)amide and the like; hydroxides such as Potassium hydroxide, Sodium hydroxide, Cesium hydroxide and the like; alkyl hydroxides such as sodium methoxide, sodium ethoxide, potassium methoxide, sodium tert-butoxide, potassium tert-butoxide and the like and mixture thereof; preferably Lithium bis(trimethylsilyl)amide, Sodium bis(trimethylsilyl)amide or sodium methoxide; more preferably Lithium bis(trimethylsilyl)amide.

The suitable solvent used herein for reaction of compound of Formula V with a compound of Formula VI is selected from the group consisting of but not limited to amides, sulfoxides, ketones, nitriles, ethers, halogenated hydrocarbons, aromatic hydrocarbons and mixtures thereof. The amides include, but are not limited to dimethylacetamide, dimethylformamide, N-methylpyrrolidone and the like and mixtures thereof; sulfoxides include, but are not limited to dimethyl sulfoxide, diethyl sulfoxide and the like and mixtures thereof; ketones include, but are not limited to acetone, methyl isobutyl ketone, methyl ethyl ketone and the like; nitriles include, but are not limited to acetonitrile, propionitrile and the like; ethers include, but are not limited to tetrahydrofuran, methyl tetrahydrofuran, dimethyl ether, diisopropyl ether, methyl tertiary butyl ether, 1,4-dioxane and the like; halogenated hydrocarbons include, but are not limited to methylene chloride, ethylene chloride, chloroform and the like; aromatic hydrocarbons include, but are not limited to toluene, xylene and the like and mixture thereof; preferably dimethylformamide, acetonitrile or tetrahydrofuran; more preferably tetrahydrofuran.

The reaction of a Formula V with a compound of Formula VI is carried out at a temperature of about -60°C to 25°C; preferably at about -40°C to about -50°C.

After completion of the reaction, the resultant product is isolated by known methods such as extraction of the product from the solution, cooling the solution to precipitation, concentration of the reaction solution, solvent crystallization and the like. Preferably the product can be isolated by extraction of the product from the solution by first adding water and water immiscible organic solvent to the reaction solution so that aqueous and organic layers are formed and the product containing organic layer can be separated easily and then concentrated by known procedures. The suitable water immiscible organic solvent includes but is not limited to toluene, ethyl acetate, methylene chloride and the like; preferably with ethyl acetate.

The resultant product may optionally be further dried at a temperature of about 35°C to about 85°C for sufficient period of time. Drying can be suitably carried out in a tray dryer, vacuum oven, air oven and the like; preferably drying is carried out under vacuum at a temperature of about 45°C to about 85°C for sufficient period of time.

d) isolating the compound of Formula VI; wherein “R” is selected from straight or branched chain Ci-6 alkyl group, and

The starting materials, a compound of Formula a VII was known in the art and can be produced by methods known and recognized by the organic chemist of ordinary skill in the art, for example US7232836. The suitable oxidizing agent in aforementioned step a) is selected from the group consisting of but not limited to hydrogen peroxide, potassium persulfate, sodium persulfate, ammonium persulfate, potassium monopersulfate, sodium monopersulfate, potassium permanganate and the like and mixture thereof; preferably potassium persulfate.

The suitable acid used in aforementioned step a) is selected from the group consisting of but not limited to acetic acid, propanoic acid, p-toluenesulphonic acid, benzoic acid, sulphuric acid, phosphoric acid, oleum, hydrobromic acid, hydrochloric acid and the like and mixture thereof; preferably sulphuric acid.

The suitable organic solvent used in aforementioned step a) is selected from the group consisting of but not limited to ketones, nitriles, ethers, esters, halogenated hydrocarbons, aromatic hydrocarbons and the like and mixtures thereof. The ketones include, but are not limited to acetone, methyl isobutyl ketone, methyl ethyl ketone and the like; nitriles include, but are not limited to acetonitrile, propionitrile and the like; ethers include, but are not limited to tetrahydrofuran, methyl tetrahydrofuran, dimethyl ether, diisopropyl ether, methyl tertiary butyl ether, 1,4-dioxane and the like; ethers include, but are not limited to ethyl acetate, isopropyl acetate, butyl acetate and the like; halogenated hydrocarbons include, but are not limited to methylene chloride, ethylene chloride, chloroform and the like; aromatic hydrocarbons include, but are not limited to toluene, xylene and the like and mixture thereof; preferably acetonitrile, tetrahydrofuran or methylene chloride; more preferably acetonitrile.

The step b) of forgoing process involves heating the step a) reaction mass to about 40°C to reflux temperature; preferably at about 75°C to about 85°C.

The step c) of forgoing process involves addition of a compound of Formula VII to the step b) reaction mass at about 75°C to about 85°C. Advantageously, compound of Formula VII is dissolved in a suitable organic solvent and added drop wise in to the step b) reaction mass for a period of about 30 min to 5 hrs at about 75°C to about 85°C. The suitable organic solvent is same as used in the step a).

After completion of the step c) reaction, undissolved salts may be separated by filtration and the compound was Formula VI can be isolated by conventional techniques such as precipitation by cooling the reaction mass, isolated by solvent precipitation, crystallization, concentrated by subjecting the solution to heating, decantation or filtration; preferably isolated by precipitation by adding a suitable solvent such as water. The resultant product may optionally be further dried at a temperature of about 35°C to about 65°C. Drying can be suitably carried out in a tray dryer, vacuum oven, air oven and the like; preferably drying is carried out under vacuum at a temperature of about 45°C for sufficient period of time.

Then the above obtained compound was Formula VI is hydrolyzed in presence of a suitable acid or base selected from hydrochloric acid, sulphuric acid, sodium hydroxide, potassium hydroxide and the like, by methods known and recognized by the organic chemist of ordinary skill in the art, for example US7232836.

The present invention provides chlorantraniliprole of Formula I prepared by the processes described as above having a purity of at least about 98%, as measured by HPLC, preferably at least about 99% as measured by HPLC.

Further, the present invention also encompasses an improved process for the preparation of compound of Formula V with high product yield and quality, wherein the improvements involve use of one -pot process without isolating intermediate compounds of Formula All and Formula AIII in a single solvent system and avoids explosives reagents, multiple solvent systems and cumbersome isolations such as time consuming solvent workups, drying and necessity of analyzing the compounds at each stage.

Formula AIII c) reacting the compound of Formula AIII with a source of chloride to obtain a compound of Formula V; wherein the step a) to c) are carried out in one -pot reaction without isolating the intermediate compound of Formula All and Formula AIII as solid.

The term RRT (relative retention time) as used in this application means in high pressure liquid chromatography (HPLC) the amount of time it takes for the compound to pass through the column is the retention time (RT) and comparison of the RT of one compound to another is called relative retention time (RRT).

The phosgene or its derivative as used in the aforementioned step a) is selected from phosgene as in gaseous form or as in liquid form consisting of but not limited to phosgene, diphosgene, triphosgene, bromophosgene and the like; preferably triphosgene.

The suitable base used for reacting a compound of Formula Al with a phosgene or its derivative in aforementioned step a) is selected from the group consisting of but not limited to inorganic bases selected from alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide and the like; alkali metal alkoxides such as sodium methoxide, sodium ethoxide, sodium tert-butoxide, potassium tert- butoxide and the like; alkali metal carbonates such as sodium carbonate, potassium carbonate, cesium carbonate and the like; alkali metal bicarbonates such as sodium bicarbonate, potassium bicarbonate and the like; organic bases selected from the group comprising of triethylamine, isopropyl ethylamine, diisopropyl amine, diisopropyl ethylamine, N-methyl morpholine, piperidine, 2-picoline, 3-picoline and the like and mixtures thereof; preferably an inorganic base such as sodium carbonate, sodium bicarbonate or potassium bicarbonate; more preferably sodium bicarbonate.

The suitable solvent used for reacting a compound of Formula Al with a phosgene or its derivative in aforementioned step a) is selected from the group consisting of but not limited to amides, esters, ketones, nitriles, ethers, halogenated hydrocarbons, aromatic hydrocarbons and the like and mixtures thereof. The amides include, but are not limited to dimethylacetamide, dimethylformamide, N-methylpyrrolidone and the like and mixtures thereof; esters include, but are not limited to ethyl acetate, methyl acetate and the like and mixtures thereof; ketones include, but are not limited to acetone, methyl isobutyl ketone, methyl ethyl ketone and the like; nitriles include, but are not limited to acetonitrile, propionitrile and the like; ethers include, but are not limited to tetrahydrofuran, methyl tetrahydrofuran, dimethyl ether, diisopropyl ether, methyl tertiary butyl ether, 1,4-dioxane and the like; halogenated hydrocarbons include, but are not limited to methylene chloride, ethylene chloride, chloroform and the like; aromatic hydrocarbons include, but are not limited to toluene, xylene and the like and mixture thereof; preferably ethyl acetate, acetonitrile or methylene chloride; more preferably methylene chloride.

The reaction of Formula Al with a phosgene or its derivative is carried out at a temperature of about 0°C to reflux temperature; preferably at about 20°C to about 40°C.

After completion of the step a) reaction, the step a) solution advantageously processed to next step by adding a source of monomethylamine to the step a) solution without isolating the compound of Formula All as a solid.

The source of monomethylamine used in aforementioned step b) is selected from the group consisting of aqueous methyl amine, methyl amine in solvent, methyl amine gas and the like; preferably aqueous methyl amine or methyl amine gas.

Optionally the reaction of compound of Formula All with a source of monomethyl amine is carried out in presence of a suitable acid, a suitable base or, a suitable second solvent. The suitable acid optionally used in aforementioned step b) is selected from the group consisting of acetic acid, formic acid, methanoic acid and the like. The suitable base optionally used in aforementioned step b) is selected from the group consisting of but not limited to inorganic bases selected from alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide and the like; alkali metal alkoxides such as sodium methoxide, sodium ethoxide, sodium tert-butoxide, potassium tert- butoxide and the like; alkali metal carbonates such as sodium carbonate, potassium carbonate, cesium carbonate and the like; alkali metal bicarbonates such as sodium bicarbonate, potassium bicarbonate and the like; organic bases selected from the group comprising of triethylamine, isopropyl ethylamine, diisopropyl amine, diisopropyl ethylamine, N-methyl morpholine, piperidine, pyridine, 2-picoline, 3-picoline and the like and mixtures thereof. The suitable second solvent optionally used in aforementioned step b) is same as the solvent used in step a) of the aforesaid process.

The reaction of a Formula All with a source of monomethylamine is carried out at a temperature of about 25 °C to reflux temperature; preferably at about 30°C to about 45°C.

After completion of the step b) reaction, the step b) solution advantageously processed to next step by adding a source of chloride to the compound of Formula AIII without isolating the compound of Formula AIII as a solid.

Optionally, after completion of the step b) reaction, the step b) solution may be washed with water to remove inorganic salts if any and then the resultant organic layer may be processed to next step by adding a source of chloride without isolating the compound of Formula AIII as a solid.

The source of chloride used in aforementioned step c) is selected from the group consisting of but not limited to sulfuryl chloride, N-chlorosuccinimide, chlorine gas, metal chloride-H₂O2 in acid aqueous medium, HCI-H2O2, m-chloroperbenzoic acid/HCl, acetyl chloride and the like; preferably sulfuryl chloride.

Optionally the step c) is carried out in presence of a suitable solvent. The suitable solvent optionally used in aforementioned step c) is same as the solvent used in step a) of the aforesaid process. The reaction of a Formula AIII with a source of chloride is carried out at a temperature of about 25°C to reflux temperature; preferably at about 30°C to about 45°C.

Generally chlorination reactions are prone to form impurities which are may be due to the reactions at other positional or side reactions with the amine moiety present in the substrate. These impurities may be identified by HPLC at RRT-0.31, RRT-0.53, RRT- 0.79, RRT-0.89, RRT-1.06, RRT-1.84, RRT-2.01, RRT-2.03, RRT-2.62, RRT-2.96, RRT-3.08 and RRT-3.11 in the range of about 2 % to about 5 % respectively along with the required compound of Formula V. Without control of these impurities at this stage the same may be carrying forwarded to subsequent stages and to final stage and at final stage one or more additional purification steps required to remove these impurities. Hence, the compound of Formula V purity is important for preparation of pure chlorantranilipr ole .

In contrast, the present invention advantageously separated these impurities by simply formation of salt of the resultant compound of Formula V after chlorination reaction and separates the salt of compound of Formula V as an aqueous layer and unwanted impurities by an organic layer.

In another embodiment, after completion of the chlorination reaction water may be added to the reaction mass and followed by adding a suitable acid to form a salt of compound of formula V in heterogeneous solvent mixture and both organic and aqueous layers may be separated. Then after separating the impurities containing organic layer the resultant compound of Formula V can be isolated from the aqueous layer by known methods, for example, adjusting pH of the aqueous layers to above 7 with a suitable base. Then the compound of Formula V can be isolated from reaction mass by conventional techniques such as solvent extraction, solvent precipitation, crystallization, concentrated by subjecting the solution to heating, decantation or filtration; preferably by filtering the solids.

The suitable acid used herein for making salt formation is selected from hydrochloric acid, sulfuric acid, acetic acid, p-toluene sulfonic acid and the like and mixture thereof; preferably hydrochloric acid and suitable base used herein for neutralization is selected from sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide and the like and mixture thereof.

The resultant product may optionally be further dried at a temperature of about 30°C to about 80°C. Drying can be suitably carried out in a tray dryer, vacuum oven, air oven and the like.

The present invention provides compound of Formula V prepared by the processes described as above having a purity of at least about 98% by HPLC, preferably at about 99.5% and having less than 0.5% by HPLC, preferably less than 0.2% by HPLC of at least one of impurities at RRT-0.31, RRT-0.53, RRT-0.79, RRT-0.89, RRT-1.06, RRT- 1.84, RRT-2.01, RRT-2.03, RRT-2.62, RRT-2.96, RRT-3.08 and RRT-3.11.

In another embodiment, the present invention provides a compound of Formula V having less than 0.5% by HPLC of at least one of impurities at RRT-0.31, RRT-0.53, RRT-0.79, RRT-0.89, RRT-1.06, RRT-1.84, RRT-2.01, RRT-2.03, RRT-2.62, RRT- 2.96, RRT-3.08 and RRT-3.11.

In another embodiment, the present invention provides an improved process for the preparation of chlorantraniliprole or a salt thereof, comprising preparing the compound of Formula V as process described above, and converting the compound of Formula V in to chlorantraniliprole or a salt thereof by any process known in the art for example W02006/062978 or by the process described in the present specification.

In another embodiment, the present invention provides crystalline chlorantraniliprole characterized by a powder X-ray diffraction (PXRD) pattern substantially in accordance with Figure 1.

In another embodiment, the present invention provides crystalline chlorantraniliprole characterized by X-Ray diffraction (XRD) pattern having at least one peak selected from at about 8.6, 10.0, 10.5, 10.6, 11.4, 11.7, 12.2, 14.0, 14.2, 14.4, 14.6, 14.9, 15.6, 16.1, 16.6, 17.3, 17.5, 17.8, 18.3, 18.5, 20.0, 20.3, 20.5, 20.7, 21.1, 21.2, 21.4, 21.5, 21.7, 22.7, 22.9, 23.4, 24.3, 24.7, 24.9, 25.3, 25.6, 26.1, 27.2, 27.5, 28.4, 29.0, 29.2, 29.4, 29.8, 30.0 and 30.3 ±0.2° 20. In another embodiment, the present invention provides a crystalline compound of Formula Ila characterized by a powder X-ray diffraction (PXRD) pattern substantially in accordance with Figure 2.

In another embodiment, the present invention provides a crystalline compound of Formula Ila characterized by X-Ray diffraction (XRD) pattern having at least one peak selected from at about 6.8, 8.2, 9.3, 10.1, 11.1, 12.4, 12.8, 13.5, 14.3, 14.8, 15.6, 15.7, 15.9, 16.5, 18.1, 18.7, 19.0, 19.5, 19.9, 20.4, 20.9, 21.7, 22.0, 22.5, 22.7, 23.2, 23.5, 24.0, 24.3, 24.8, 25.3, 25.9, 26.4, 27.2, 27.7, 27.9, 28.3, 28.9, 29.1, 29.2, 29.8 and 30.5 ±0.2° 20.

In another embodiment, the present invention provides a composition comprising chlorantraniliprole, prepared by the processes of the present invention and/or at least one excipient.

In another embodiment, the present invention relates to a one -pot process for preparation of chlorantraniliprole of Formula I, which is depicted in below scheme:

In another embodiment, the present invention relates to a process for preparation of chlorantraniliprole of Formula I, which is depicted in below scheme:

In another embodiment, the present invention relates to a process for preparation of chlorantraniliprole of Formula I, which is depicted as follows:

wherein "R" is selected from straight orbranched chain Cj-₆ alkyl group

The present invention provides chlorantraniliprole and its intermediates, obtained by the above process, as analyzed using high performance liquid chromatography (“HPLC”) with the conditions are tabulated below:

EXAMPLES

The following non-limiting examples illustrate specific embodiments of the present invention. They are not intended to be limiting the scope of the present invention in any way.

EXAMPLE-1:

Preparation of chlorantraniliprole

Compound of Formula III (R=Me; 66 gm) and Formula IV (100 gm), 3-picoline (77 gm) and acetonitrile (500 mL) were added in to a round bottom flask at about 25°C to about 30°C and stir for 10 min at same temperature. Reaction mass was cool to 0-5°C and was added methanesulfonyl chloride (45.5 gm) and stir for 1 hr at same temperature. Then the reaction mass was allowed to 25-30°C and stir for 2 hrs at same temperature. After completion of the reaction, reaction mixture was washed with water (600 mL). Then the organic layer was cool to 0-5°C and was passed methyl amine gas (86 gm) and stir fir 1 hr at same temperature. Then the reaction mass was allowed to 25- 30°C and stir for 4 hrs at same temperature. After completion of the reaction, reaction mass was concentrated under vacuum at below 50°C and co-distilled with methanol (50 mL) to obtain a solid. To the solid was added methanol (50 mL) and heated to reflux for 1 hr. Reaction mass was cool to 25-30°C and stir for 4 hr at same temperature. Then the solid was filtered and washed with methanol (50 mL) and dry the wet material initially at 25-30°C for 30-60 min, then dry at 60-65°C for 6 hr to obtain title compound. Wt: 160 gm. Purity by HPLC: 99.5%; PXRD: Fig 1; TGA: No weight loss; DSC: Endothermic peaks at 204°C and 237.2°C.

EXAMPLE-2:

Preparation of chlorantraniliprole

Compound of Formula III (R=Me; 66 gm) and Formula IV (100 gm), 3-picoline (77 gm) and methylene chloride (500 mL) were added in to a round bottom flask at about 25°C to about 30°C and stir for 10 min at same temperature. Reaction mass was cool to 0-5°C and was added methanesulfonyl chloride (45.5 gm) and stir for 1 hr at same temperature. Then the reaction mass was allowed to 25-30°C and stir for 2 hrs at same temperature. After completion of the reaction, reaction mixture was cool to 0-5°C and was passed methyl amine gas (82 gm) and stir fir 1 hr at same temperature. Then the reaction mass was allowed to 25-30°C and stir for 4 hrs at same temperature. After completion of the reaction, reaction mass was concentrated under vacuum at below 50°C and co-distilled with acetone (50 mL) to obtain a solid. To the solid was added acetone (300 mL) and heated to reflux for 1 hr. Reaction mass was cool to 25-30°C and stir for 4 hr at same temperature. Then the solid was filtered and washed with acetone (50 mL) and dry the wet material initially at 25-30°C for 30-60 min, then dry at 60- 65°C for 6 hr to obtain title compound. Wt: 159 gm.

EXAMPLE-3:

Preparation of chlorantraniliprole

Compound of Formula III (R=Me; 66 gm) and Formula IV (100 gm), 3-picoline (77 gm) and acetonitrile (500 mL) were added in to a round bottom flask at about 25°C to about 30°C and stir for 10 min at same temperature. Reaction mass was cool to 0-5°C and was added methanesulfonyl chloride (45.5 gm) and stir for 1 hr at same temperature. Then the reaction mass was allowed to 25-30°C and stir for 2 hrs at same temperature. After completion of the reaction, reaction mass was cool to 0-5°C and was passed methyl amine gas (86 gm) and stir fir 1 hr at same temperature. Then the reaction mass was allowed to 25-30°C and stir for 4 hrs at same temperature. After completion of the reaction, reaction mass was concentrated under vacuum at below 50°C and co-distilled with methanol (50 mL) to obtain a solid. To the solid was added methanol (50 mL) and heated to reflux for 1 hr. Reaction mass was cool to 25-30°C and stir for 4 hr at same temperature. Then the solid was filtered and washed with methanol (50 mL) and dry the wet material initially at 25-30°C for 30-60 min, then dry at 60- 65°C for 6 hr to obtain title compound. Wt: 163 gm. Purity by HPLC: 99.6%

EXAMPLE-4:

Preparation of compound of Formula II (R= methyl)

Compound of Formula III (R=Me; 66 gm) and Formula IV (100 gm), 3-picoline (92.3 gm) and acetonitrile (500 mL) were added in to a round bottom flask at about 25°C to about 30°C and stir for 10 min at same temperature. Reaction mass was cool to 0-5°C and was added methanesulfonyl chloride (53.1 gm) at same temperature. Then the reaction mass was allowed to 25-30°C and stir for 1 hrs at same temperature. After completion of the reaction, to the reaction mass was charged water (250 mL) at 25-30°C and stir for 1 hrs at same temperature. Precipitated solid was filtered and washed with water (100 mL) and dried the wet material under vacuum at 50-60°C to obtain title compound. Wt: 160 gm; PXRD: Fig 3; TGA: 0.08%; DSC: Endothermic peaks at 155.5°C and 176°C.

EXAMPLE S;

Preparation of chlorantraniliprole

Compound of Formula II (R=Me; 100 gm) and acetonitrile (300 mL) were added in to a round bottom flask at about 25°C to about 30°C. Reaction mass was cool to 0-5°C and was passed methyl amine gas at same temperature for 1 to 1.5 hrs. Then the reaction mass was allowed to 25-30°C and stir for 12 hrs at same temperature. After completion of the reaction, to the reaction mass was charged water (150 mL) at 25-30°C. Precipitated solid was filtered and washed with water (50 mL), acetonitrile (50 mL) and dried the wet material under vacuum at 50-60°C to obtain title compound. Wt: 90 gm. Purity by HPLC: 99.4%.

EXAMPLE-6:

Preparation of chlorantraniliprole

Compound of Formula II (R=Me; 100 gm) and acetonitrile (300 mL) were added in to a round bottom flask at about 25°C to about 30°C. To the reaction mass was added aqueous methylamine (10 gm) at about 25°C to about 30°C and stir for 24 hrs at same temperature. After completion of the reaction, to the reaction mass was charged water (150 mL) at 25-30°C. Precipitated solid was filtered and washed with water (50 mL), acetonitrile (50 mL) and dried the wet material under vacuum at 50-60°C to obtain title compound. Wt: 93 gm.

EXAMPLE-7:

Preparation of chlorantraniliprole

Compound of Formula VI (R’=Ethyl; 100 gm) and tetrahydrofuran (500 mL) were added in to a round bottom flask at about 25°C to about 30°C. To the reaction mass was added compound of Formula V (60.1 gm) at about 25°C to about 30°C. Then reaction mass was cool to about -40°C to about -50°C and was added IM LiHMDS in tetrahydrofuran (906 mL) at same temperature and stir for 1 hr at same temperature. After completion of the reaction, to the reaction mass was charged water (1 lit) and ethyl acetate (1 lit) at about -40°C to about -50°C. Reaction mass temperature was heated to 25-30°C and separated the organic and aqueous layers. Organic layer was concentrated under vacuum at 40-45°C to obtain a solid. Then the obtained solid was mixed with acetonitrile (500 mL) at 25-30°C. To the reaction mass was added water (250 mL) at 25-30°C and stir for 1 hr at same temperature. Precipitated solid was filtered and washed with water (100 mL), acetonitrile (50 mL) and dried the wet material under vacuum at 50-60°C to obtain title compound. Wt: 75 gm.

EXAMPLE S:

Preparation of compound of Formula IV i) Preparation of (3-chloropyridin-2-yl) hydrazine

2,3-Dichloropyridine (100 gm), ethanol (150 mL) and hydrazine hydrate (162 mL) were added in to a round bottom flask at about 25°C to about 30°C. Reaction mass was heated to reflux for 15 hrs. After completion of the reaction, reaction mass was cool to 25-30°C and was added water (100 mL). The precipitated solid compound was filtered and washed with water (300 mL) and dried the wet material under vacuum at 65-75°C to obtain title compound. Wt: 101 gm. ii) Preparation of 2-(3-Chloro pyridin-2-yl)-5-oxo-pyrazolidine-3-carboxylic acid ethyl ester

Sodium ethoxide (21% w/w) in ethanol (300 mL) and ethanol (250 mL) were added in to a round bottom flask at about 25°C to about 30°C. Reaction mass was heated to about 55-60°C for 5-10 min. To the reaction mass was added of (3-chloropyridin-2-yl) hydrazine (100 gm) and diethyl maleate (132.6 gm) at 55-60°C. After completion of the reaction, reaction mass was cool to 25-30°C and was added acetic acid (90 mL) at same temperature. Then the reaction mass was completely concentrated under vacuum at below 50°C to obtain a residue. To the residue was added water (500 mL) and the product was extracted with methylene chloride (500 mL). Organic layer was concentrate completely under vacuum at below 40°C. Then the obtained product was crystallized from ethanol and dried the wet material under vacuum at 50-55°C to obtain title compound. Wt: 120 gm. iii) Preparation of Ethyl 3-bromo-l-(3-chloro-2-pyridinyl)-4,5-dihydro-lH-pyrazole-5- carboxylate (Formula VII)

2-(3-Chloro pyridin-2-yl)-5-oxo-pyrazolidine-3-carboxylic acid ethyl ester (100 gm), acetonitrile (200 mL) and Phosphoryl bromide (84.9 gm) were added in to a round bottom flask at about 25°C to about 30°C. Reaction mass was heated to reflux for 4 hrs. After completion of the reaction, reaction mass was cool to 25-30°C and was added water (500 mL) and extracted with methylene chloride (500 mL). Then the organic layer was washed with 5% Sodium metabisulphite solution (500 mL) and followed by 5% sodium bicarbonate solution (500 mL). Organic layer was concentrate completely under vacuum below 40°C to obtain title compound. Wt: 120 gm. iv) Preparation of Ethyl 3-bromo-l-(3-chloro-2-pyridinyl)-lH-pyrazole-5-carboxylate (Formula VI; ethyl)

Sulphuric acid (58.98 gm), potassium persulfate (119.5 gm) and acetonitrile (200 mL) were added in to a round bottom flask at about 25°C to about 30°C. Reaction mass was heated to reflux and was added solution of ethyl 3-bromo-l-(3-chloro-2-pyridinyl)-4,5- dihydro-lH-pyrazole-5-carboxylate (100 gm dissolved in 100 mL acetonitrile) and stir for 3 hrs at same temperature. After completion of the reaction, reaction mass was cool to 60-65°C and undissolved salts were filtered. Ten the filterate was added in to water (500 mL) at 25-30°C and stir for 2 hrs at same temperature. The precipitated solid compound was filtered and washed with water (100 mL) and dried the wet material under vacuum at 50-55°C to obtain title compound. Wt: 94.6 gm. v) Preparation of 3-Bromo-l-(3-chloro-2-pyridinyl)-lH-pyrazole-5-carboxylic acid (Formula IV)

Ethyl 3-bromo-l-(3-Chloro-2-pyridinyl)-lH-pyrazole-5-carboxylate (100 gm), methanol (300 mL), water (200 mL) and sodium hydroxide (13.31 gm) were added in to a round bottom flask at about 25°C to about 30°C and stir for 2 hrs at same temperature. After completion of the reaction, concentrated the solvent under vacuum at below 50°C and was added water (500 mL). Aqueous layer was cool to 5°C and pH was adjusted to 1.5 ±0.5 with hydrochloric acid at 5°C. The precipitated solid compound was filtered and washed with water (100 mL) and dried the wet material under vacuum at 50-55°C to obtain title compound. Wt: 80 gm.

EXAMPLE-9:

Preparation of compound of Formula V

Thiophosgene solution (78.5 gm) and 700 mL methylene chloride was were added in to a round bottom flask at room temperature and stir for 10 min at 10°C to 20°C. To the solution was added compound of Formula Al (100 gm), sodium bicarbonate (138.9 gm) and stir for 10-20 min at same temperature. Reaction mass was heated 25-35°C and stir for 6 hrs at same temperature. After completion of the reaction, to the reaction mass was added 40% aqueous monomethylamine (154 gm) at 10-20°C and stir for 3 hrs at 25- 35°C. After completion of the reaction, to the reaction mass was added water (700 mL) and product containing organic layer was separated. To the product containing organic layer sulfuryl chloride (133.6 gm) was added slowly at 10-20°C and stir for 6 hrs at 25- 35°C. After completion of the reaction, to the reaction mass was added water (500 mL) and hydrochloric acid (150 mL) at 10-20°C and stir for 20 min at 25-35°C. Aqueous and organic layers were separated and product containing aqueous layer pH was adjusted to 8.0-9.0 with aq sodium hydroxide solution at 25°C to 35°C and stir for 30 min at same temperature. Filtered the solids and washed the wet cake with water (100 mL) and dry the wet material initially at 25-35°C for 60 min, then dry at 60-75°C for 6 hr to obtain title compound. Wt: 106 gm; Yield: 79%; HPLC Purity: 99.5%;

The organic layer was taken and concentrated completely under vacuum to obtain a residue and analyzed the residue by HPLC and the results are as follows:

EXAMPLE-10:

Preparation of compound of Formula V

Compound of Formula Al (100 gm), methylene chloride (500 mL), sodium bicarbonate (138.9 gm) were added in to a round bottom flask and allowed to cool to 0-10°C and stir for 10-20 min at same temperature. To the reaction mass was added triphosgene solution (78.5 gm dissolved in 200 mL methylene chloride) at 0-10°C. Reaction mass was heated 25-35°C and stir for 6 hrs at same temperature. After completion of the reaction, to the reaction mass was added acetic acid (7.9 gm) and 40% aqueous monomethylamine (102.7 gm) at 25-35°C and stir for 3 hrs at same temperature. After completion of the reaction, to the reaction mass water (100 mL) was added and product containing organic layer was separated. To the product containing organic layer Sulfuryl chloride (134.1 gm) was added slowly at 25-35°C and stir for 3 hrs at same temperature. After completion of the reaction, reaction mass was cool to 0-5°C and was added water (500 mL) at same temperature. pH of the reaction mass was adjusted to 9.5 with aq sodium hydroxide solution at -5°C to 5°C and stir for 30 min at same temperature. Then the product containing organic layer was separated and aqueous layer was extracted with methylene chloride (200 mL). The combined organic layer was concentrated under vacuum at below 40°C to get semi solid. To the solids was added a mixture of methanol (50 mL) and water (450 mL) at 25-35°C and stir for 3 hrs at same temperature. Filtered the solids and washed the wet cake with water (100 mL) and dry the wet material initially at 25-35°C for 60 min, then dry at 60-75°C for 6 hr to obtain title compound. Wt: 105gm; Yield: 78.3%.

EXAMPLE-11:

Preparation of Chlorantraniliprole

3-Bromo-l-(3-chloro-2-pyridinyl)-lH-pyrazole-5-carboxylic acid ethyl ester (100 gm) and tetrahydrofuran (500 mL) were added in to a round bottom flask at about 25°C to about 30°C. To the reaction mass was added compound of Formula V (60.1 gm) at about 25°C to about 30°C. Then reaction mass was cool to about -40°C to about -50°C and was added IM LiHMDS in tetrahydrofuran (906 mL) at same temperature and stir for 1 hr at same temperature. After completion of the reaction, to the reaction mass was charged water (1 lit) and ethyl acetate (1 lit) at about -40°C to about -50°C. Reaction mass temperature was heated to 25-30°C and separated the organic and aqueous layers. Organic layer was concentrated under vacuum at 40-45°C to obtain a solid. Then the obtained solid was mixed with acetonitrile (500 mL) at 25-30°C. To the reaction mass was added water (250 mL) at 25-30°C and stir for 1 hr at same temperature. Precipitated solid was filtered and washed with water (100 mL), acetonitrile (50 mL) and dried the wet material under vacuum at 50-60°C to obtain title compound. Wt: 100 gm.

REFERENCE EXAMPLE-1:

Preparation of compound of Formula All

Compound of Formula Al (100 gm) and methylene chloride (500 mL) were added in to a round bottom flask and allowed to cool to 0-10°C. To the reaction mass was slowly added pyridine (104.4 gm) and triphosgene (68.7 gm dissolved in 100 mL methylene chloride) at 0-10°C and stir for 2 hrs at same temperature. Reaction mass was heated 25-35°C and stir for 6 hrs at same temperature. After completion of the reaction, to the reaction mass was added water (100 mL), cool to 10°C and stir for 3 hrs at same temperature. Precipitated solids were filtered and washed with water (100 mL) and dry the wet material initially at 30-35°C for 60 min, then dry at 60-75°C for 6 hr to obtain title compound. Wt: 105 gm.

REFERENCE EXAMPLE-2:

Preparation of compound of Formula AIII

Compound of Formula All (100 gm), acetic acid (5.8 mL) and methylene chloride (425 mL) were added in to a round bottom flask and heated to 30-35°C. To the reaction mass was added 40% aq methylamine solution (58 gm) and stir for 3 hrs at 30-35°C. After completion of the reaction, to the reaction mass was added water (85 mL) and extracted product in to methylene chloride (85 mL). Combined organic layer was concentrated under vacuum at below 55°C and dry the wet material initially at 45-50°C to obtain title compound. Wt: 83 gm.

REFERENCE EXAMPLE-3:

Preparation of compound of Formula V Compound of Formula AIII (80 gm), methylene chloride (340 mL) and Sulfuryl chloride (61.5 gm) were added in to a round bottom flask at 30-35°C and stir for 3 hrs at same temperature. After completion of the reaction, to the reaction mass was added water (70 mL) and pH adjusted to 8.5 to 9.5 with lye solution at -5°C to 5°C and stir for 30 min at same temperature. Then the product containing organic layer was separated and was concentrated under vacuum at below 40°C to get semi solid. To the solids was added a mixture of methanol (35 mL) and water (300 mL) at 25-35°C and stir for 3 hrs at same temperature. Filtered the solids and washed the wet cake with water (70 mL) and dry the wet material initially at 25-35°C for 60 min, then dry at 60-75°C for 6 hr to obtain title compound. Wt: 78 gm.

It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore the above description should not be constructed as limiting, but merely as exemplifications of preferred embodiments. For example, the functions described above and implemented as the best mode for operating the present invention are for illustration purposes only. Other arrangements and methods may be implemented by those skilled in the art without departing from the scope and spirit of this invention. Moreover, those skilled in the art will envision other modifications within the scope and spirit of the specification appended hereto.

Claims

We Claim:

1. A process for preparation of chlorantraniliprole of Formula I, comprising:

2. The process as claimed in claim 1, wherein in the Ci-6 alkyl group is selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert butyl, pentyl, isopentyl, hexyl, isohexyl and isoamyl.

3. The process as claimed in claim 1, wherein in the suitable activating agent is selected from the group consisting thionyl chloride, pivaloyl chloride, methane sulfonyl chloride, ethane sulfonyl chloride, benzene sulfonyl chloride, p- toluenesulfonyl chloride, p- nitro sulfonyl chloride, carbonyldiimidazole, diisopropylcarbodiimide, N-(3-dimethylaminopropyl)-N’ -ethyl carbodiimide, dicyclohexyl carbodiimide, propanephosphonic acid cyclic anhydride, benzotriazol- 1-yl-oxytripyrrolidino phosphonium hexafluorophosphate, bromo- tripyrrolidino- phosphonium hexafluorophosphate, benzotriazol- 1-yloxy-tris (dimethylamino)- phosphonium hexafluorophosphate, Propylphosphonic anhydride, 2-(7-Aza-lH- benzotriazol-l-yl)- N,N,N’,N’ -tetra methylaminium hexafluorophosphate), (1- cyano-2-ethoxy-2-oxoethyl idenaminooxy)dimethylamino-morpholino-carbenium hexa fluorophosphate, N,N,N',N'-Tetramethyl-O-(lH-benzotriazol- l-yl)uronium hexafluoro phosphate, O -(benzotriazol- l-yl)-N,N,N',N'-tetramethyluronium hexafluoro phosphate, 2-( IH-Benzotriazol- l-yl)-N,N,N’ ,N’ -tetramethylaminium tetrafluoroborate and mixture thereof. The process as claimed in claim 1, wherein in the suitable base is selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium methoxide, sodium ethoxide, sodium tert-butoxide, potassium tert-butoxide, sodium carbonate, potassium carbonate, cesium carbonate, sodium bicarbonate, potassium bicarbonate, triethylamine, isopropyl ethylamine, diisopropyl amine, diisopropyl ethylamine, N-methyl morpholine, piperidine, pyridine, 2-picoline, 3- picoline and mixtures thereof. The process as claimed in claim 1, wherein in the suitable solvent is selected from the group consisting of dimethylacetamide, dimethylformamide, N- methylpyrrolidone, dimethyl sulfoxide, diethyl sulfoxide, acetone, methyl isobutyl ketone, methyl ethyl ketone, acetonitrile, propionitrile, tetrahydrofuran, methyl tetrahydrofuran, dimethyl ether, diisopropyl ether, methyl tertiary butyl ether, 1,4- dioxane, methylene chloride, ethylene chloride, chloroform, toluene, xylene and mixtures thereof. The process as claimed in claim 1, wherein the step a) reaction is carried out at a temperature of about 20°C to about 35°C. The process as claimed in claim 1, wherein in the step b) is carried out by one-pot reaction without isolating the compound of Formula II as a solid. The process as claimed in claim 1, wherein in source of monomethylamine is selected from the group consisting of aqueous methyl amine, methyl amine in solvent and methyl amine gas. The process as claimed in claim 1, wherein in the alkyl group is methyl; wherein in the activating agent is methane sulfonyl chloride or thionyl chloride; wherein in the base is 3-picoline; wherein in the solvent is acetonitrile or methylene chloride; and wherein in the source of monomethylamine is aqueous methyl amine or methyl amine gas. The process as claimed in claim 1, wherein the step b) reaction is carried out at a temperature of about 30°C to about 40°C. The process as claimed in claim 1, wherein the process further comprises: a) cooling the step a) solution containing compound of Formula II to below 25°C, b) adding a source of monomethylamine to the step a) solution, c) heating the step b) to about 25°C to reflux temperature, d) concentrating the step c) reaction mass to obtain a solid compound, e) adding a suitable organic solvent to the step d) and heating to reflux temperature, f) cooling the solution to below 35°C, and g) filtering the chlorantraniliprole. The process as claimed in claim 11, wherein in the suitable organic solvent in step e) is selected from the group consisting of methanol, ethanol, butanol, pentanol, isopropanol, isopentanol, acetone, methyl isobutyl ketone, methyl ethyl ketone, tetrahydrofuran, methyl tetrahydrofuran, dimethyl ether, diisopropyl ether, methyl tertiary butyl ether, 1,4-dioxane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, methyl cyclohexane, cycloheptane, cyclooctane and mixture thereof. The process as claimed in claim 12, wherein in the organic solvent is methanol or acetone. An improved process for preparation of chlorantraniliprole of Formula I,

comprising: reacting a compound of Formula V

with a compound of Formula VI; wherein “R” is selected from straight or branched chain Ci-6 alkyl group,

Formula VI in presence of a suitable base and a suitable solvent to obtain chlorantraniliprole. The process as claimed in claim 14, wherein the Ci-6 alkyl group is selected from the group consisting of methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, tert-butyl, pentyl, iso-pentyl, hexyl, iso-hexyl and iso-amyl. The process as claimed in claim 14, wherein the suitable base is selected from the group consisting of Lithium bis(trimethylsilyl)amide, Sodium bis(trimethylsilyl)amide, Potassium bis(trimethylsilyl)amide, Potassium hydroxide, Sodium hydroxide, Cesium hydroxide, sodium methoxide, sodium ethoxide, potassium methoxide, sodium tert-butoxide, potassium tert-butoxide and mixture thereof. The process as claimed in claim 14, wherein the suitable solvent is selected from the group consisting of dimethylacetamide, dimethylformamide, N- methylpyrrolidone, dimethyl sulfoxide, diethyl sulfoxide, acetone, methyl isobutyl ketone, methyl ethyl ketone, acetonitrile, propionitrile, tetrahydrofuran, methyl tetrahydrofuran, dimethyl ether, diisopropyl ether, methyl tertiary butyl ether, 1,4- dioxane, methylene chloride, ethylene chloride, chloroform, toluene, xylene and mixture thereof.

18. The process as claimed in claim 14, wherein the alkyl group is ethyl; wherein the base is Lithium bis (trimethylsilyl) amide; and wherein the solvent is tetrahydrofuran.

19. The process as claimed in claim 14, wherein the reaction is carried out at a temperature of about -40°C to about -50°C. 0. An improved process for preparation of a compound of Formula IV, comprising:

Formula IV a) mixing a suitable oxidizing agent, a suitable acid and a suitable organic solvent, b) heating the reaction mass to about 40°C to reflux temperature, c) adding a compound of Formula VII to the above step b) reaction mass,

Formula VI e) hydrolyzing the compound of formula VI, wherein “R” is selected from straight or branched chain Ci-6 alkyl group to obtain a compound of Formula IV.

21. The process as claimed in claim 20, wherein the suitable oxidizing agent is selected from the group consisting of hydrogen peroxide, potassium persulfate, sodium persulfate, ammonium persulfate, potassium monopersulfate, sodium monopersulfate, potassium permanganate and mixture thereof.

22. The process as claimed in claim 20, wherein the suitable acid is selected from the group consisting of acetic acid, propanoic acid, p-toluenesulphonic acid, benzoic acid, sulphuric acid, phosphoric acid, oleum, hydrobromic acid, hydrochloric acid and mixture thereof.

23. The process as claimed in claim 20, wherein the suitable organic solvent is selected from the group consisting of acetone, methyl isobutyl ketone, methyl ethyl ketone, acetonitrile, propionitrile, tetrahydrofuran, methyl tetrahydrofuran, dimethyl ether, diisopropyl ether, methyl tertiary butyl ether, 1,4-dioxane, ethyl acetate, isopropyl acetate, butyl acetate, methylene chloride, ethylene chloride, chloroform, toluene, xylene and mixture thereof.

24. The process as claimed in claim 20, wherein the acid is sulphuric acid; wherein the oxidizing agent is potassium persulfate; and wherein the organic solvent is acetonitrile.

25. The process as claimed in claim 20, wherein the step e) is carried out in presence of a suitable acid or a base.

26. The process as claimed in claim 25, wherein the step e) is carried out using hydrochloric acid, sulphuric acid, sodium hydroxide or potassium hydroxide.

27. An improved process for preparation of compound of Formula V, comprising:

28. The process as claimed in claim 27, wherein in the phosgene or its derivative is selected from the group consisting of phosgene, diphosgene, triphosgene and bromophosgene.

29. The process as claimed in claim 27, wherein in the suitable base is selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium methoxide, sodium ethoxide, sodium tert-butoxide, potassium tert-butoxide, sodium carbonate, potassium carbonate, cesium carbonate, sodium bicarbonate, potassium bicarbonate, triethylamine, isopropyl ethylamine, diisopropyl amine, diisopropyl ethylamine, N-methyl morpholine, piperidine, 2-picoline, 3-picoline and mixtures thereof.

30. The process as claimed in claim 27, wherein in the suitable solvent is selected from the group consisting of dimethylacetamide, dimethylformamide, N- methylpyrrolidone, ethyl acetate, methyl acetate, acetone, methyl isobutyl ketone, methyl ethyl ketone, acetonitrile, propionitrile, tetrahydrofuran, methyl tetrahydrofuran, dimethyl ether, diisopropyl ether, methyl tertiary butyl ether, 1,4- dioxane, methylene chloride, ethylene chloride, chloroform, toluene, xylene and mixture thereof.

31. The process as claimed in claim 27, wherein the step a) reaction is carried out at a temperature of about 0°C to reflux.

32. The process as claimed in claim 27, wherein in the source of monomethyl amine is selected from the group consisting of aqueous methyl amine, methyl amine in solvent and methyl amine gas.

33. The process as claimed in claim 27, wherein the step b) reaction is carried out at a temperature of about 25°C to reflux.

34. The process as claimed in claim 27, wherein in the source of chloride is selected from the group consisting of sulfuryl chloride, N-chlorosuccinimide, chlorine gas, metal chloride -H2O2 in acid aqueous medium, HCI-H2O2, m-chloroperbenzoic acid/HCl and acetyl chloride.

35. The process as claimed in claim 27, wherein the step c) reaction is carried out at a temperature of about 25°C to reflux.

36. The process as claimed in claim 27, wherein in the phosgene or its derivative is triphosgene, wherein in the base is sodium carbonate, sodium bicarbonate or potassium bicarbonate; wherein in the solvent is ethyl acetate, acetonitrile or methylene chloride; wherein in the source of monomethyl amine is aqueous methyl amine or methyl amine gas; and wherein in the source of chloride is sulfuryl chloride.

37. An improved process for preparation of compound of Formula V having less than 0.5% by HPLC of at least one of impurities at RRT-0.31, RRT-0.53, RRT-0.79, RRT-0.89, RRT-1.06, RRT-1.84, RRT-2.01, RRT-2.03, RRT-2.62, RRT-2.96, RRT-3.08 and RRT-3.11, comprising: a) reacting a compound of Formula AIII with a source of chloride to obtain a solution containing compound of Formula V having more than 0.5% by HPLC of at least one of impurities at RRT-0.31, RRT-0.53, RRT-0.79, RRT-0.89, RRT-1.06, RRT-1.84, RRT-2.01, RRT-2.03, RRT-2.62, RRT-2.96, RRT-3.08 and RRT-3.11, b) adding water and a suitable acid to the step a) solution, c) separating the organic and aqueous layers, d) adding a suitable base to the aqueous layer, and e) filtering the compound of Formula V.

38. The process as claimed in claim 37, wherein in the source of chloride is selected from the group consisting of sulfuryl chloride, N-chlorosuccinimide, chlorine gas, metal chloride -H2O2 in acid aqueous medium, HCI-H2O2, m-chloroperbenzoic acid/HCl and acetyl chloride; wherein the suitable acid is selected from the group consisting of hydrochloric acid, sulfuric acid, acetic acid, p-toluene sulfonic acid and mixture thereof; and wherein the base is selected from the group consisting of sodium hydroxide, potassium hydroxide, caesium hydroxide, lithium hydroxide and mixture thereof.

39. A compound of Formula V having less than 0.5% by HPLC of at least one of impurities at RRT-0.31, RRT-0.53, RRT-0.79, RRT-0.89, RRT-1.06, RRT-1.84, RRT-2.01, RRT-2.03, RRT-2.62, RRT-2.96, RRT-3.08 and RRT-3.11.

40. Crystalline chlorantraniliprole having an X-Ray diffraction (XRD) at least one peak selected from at about 8.6, 10.0, 10.5, 10.6, 11.4, 11.7, 12.2, 14.0, 14.2, 14.4, 14.6,

14.9, 15.6, 16.1, 16.6, 17.3, 17.5, 17.8, 18.3, 18.5, 20.0, 20.3, 20.5, 20.7, 21.1, 21.2,

21.4, 21.5, 21.7, 22.7, 22.9, 23.4, 24.3, 24.7, 24.9, 25.3, 25.6, 26.1, 27.2, 27.5, 28.4,

29.0, 29.2, 29.4, 29.8, 30.0 and 30.3 ±0.2° 20.

41. Crystalline compound of Formula Ila

Formula Ila having an X-Ray diffraction (XRD) at least one peak selected from at about 6.8,

8.2, 9.3, 10.1, 11.1, 12.4, 12.8, 13.5, 14.3, 14.8, 15.6, 15.7, 15.9, 16.5, 18.1, 18.7,

19.0, 19.5, 19.9, 20.4, 20.9, 21.7, 22.0, 22.5, 22.7, 23.2, 23.5, 24.0, 24.3, 24.8, 25.3,5.9, 26.4, 27.2, 27.7, 27.9, 28.3, 28.9, 29.1, 29.2, 29.8 and 30.5 ±0.2° 20. composition comprising chlorantraniliprole prepared by the processes accordingo claims 1-41 and/or at least one excipient.

50