A method for the synthesis of substituted anthranilic amide compounds, intermediates and salts thereof

Abstract

The present invention discloses a method for the synthesis of compounds of formula (I) or a salt thereof, wherein, R is selected from hydrogen, halogen, cyano, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; R4 is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-C1-C10 alkyl; and n represents an integer selected from 0-4. The method further comprises the synthesis of an anthranilic diamide compound of formula (A).

Description

A METHOD FOR THE SYNTHESIS OF SUBSTITUTED ANTHRANILIC AMIDE COMPOUNDS, INTERMEDIATES AND SALTS THEREOFFIELD OF THE INVENTION:

[0001] The present invention is related to a method for the synthesis of substituted anthranilic amide compounds, their salts, intermediates used for their preparation, and their salts. Particularly, the present invention relates to a method for the synthesis of di-substituted 2-amino-A-alkyl-benzamide compounds of formula (I), their intermediates and salts thereof.BACKGROUND OF THE INVENTION:

[0002] Anthranilic amide compounds are important intermediates for various pharmaceutically or agrochemically active ingredients.

[0003] WO2012103436 and WO2013117601 describe the preparation of anthranilic amides from 2-halo aniline derivatives using hazardous carbon monoxide gas and an appropriate palladium catalyst, which as such is a disadvantage from safety and economy point of view.

[0004] The method described in the Journal of Heterocyclic Chemistry 2016, 53(4), 1036-1045 involves five steps in order to achieve the synthesis of an anthranilic amide compound. Furthermore, the method described in WO2012161313 involves the usage of n-butyl lithium, which is pyrophoric and can be difficult to handle on a larger scale.

[0005] W02020170092 describes a process for preparing substituted anthranilic diamides and intermediates thereof, particularly, discloses the process for the synthesis of substituted anthranilic amides of formula (VII) from substituted isatin derivatives via the formation of substituted isatoic anhydride intermediates, as shown in scheme-A:

[0006] Similarly, WO2021086957 describes the synthesis of substituted anthranilic amides from substituted isatin derivatives via the formation of substituted isotoic anhydride intermediates, as shown in scheme 1:Scheme J .

[0007] The reaction sequence described in the above cited prior art involves more than two steps to prepare the substituted anthranilic amide compounds from the respective substituted isatin intermediates, which involves additional operation cost and an increased consumption of solvents to isolate the respective substituted intermediates, and thereby making the process environmentally not friendly.

[0008] WO2022058916 describes the synthesis of substituted anthranilic amides of formula (Z) from reacting substituted anilines of formula (II) with the trihaloacetonitriles (IX), followed by reacting the substituted trihaloacetyl intermediates (Z), wherein R10is (CX3), with suitably substituted amines of formula (A) to obtain the substituted anthranilic amides of formula (Z) as shown in the scheme below:

[0009] The substituted trihaloacetyl intermediates (Z), wherein R10is CX3, was prepared by using a combination of the Lewis acid reagent BCI3-AICI3 which is uneconomical as well as difficult to handle at a large scale.

[0010] Further, WO2022064454A1 reports the synthesis of isatin derivatives (V) and amide (VII). In this document, the amine (II) is reacted with a carbonyl compound (III) to obtain an amide (IV), which is further cyclized by treatment with an acid to obtain an isatin of formula (V). After that, the isatin offormula (V) is treated with an oxidizing agent and a catalyst to obtain an isatoic anhydride of formula (VI). Finally, the isatoic anhydride of formula (VI) is reacted with HN(R4a)(R4b) (VIII) to obtain the amide (VII).

[0011] This amide (VII) of WO2022064454A1 is one of the targets, compounds of formula (I), of the present invention.

[0012] According to WO2022064454A1, the conversion of isatin of formula (V) to the amide of formula (VII) occurs in two steps - (a) isatin (V) to isatoic anhydride (VI), and (b) isatoic anhydride (VI) to amide (VII). The conversion of isatin to isatoic anhydride is carried out using A-methylpyrrolidone as solvent, selenous acid as catalyst, tungstic acid and hydrogen peroxide as a catalyst. Thereafter, this isatoic anhydride is isolated and reacted with a primary amine along with a solvent and pyridine to obtain the amide VII.

[0013] From the above discussion it is noted that the conversion of isatin of formula (V) to the amide of formula (VII) proceeds through the isatoic anhydride intermediate of formula (VI). This route to for the synthesis of the amide suffers from low yields, utilizes numerous solvents and catalysts and involves purification and isolation steps, which makes this prior art process unfit for commercial production on a large scale. Accordingly, there is a need for a process for the conversion of an isatin to an amide that does not involve the use of expensive solvents and catalysts, and isolation and purification steps.

[0014] It is also noted that as per WO2022064454A1, the conversion of the (IVb) to the isatin (V). This route to get the amide of formula (Vll)also suffers from low yields, utilizes numerous solvents and involves purification and isolation at every step, which makes this prior art process unfit for commercial production on alarge scale. Accordingly, there is a need for a process for the conversion of an ester (IVb) to an amide (VII) that does not involve the use of expensive solvents and catalysts, and isolation and purification step after every step.

[0015] The above literature methods are tedious as well as have disadvantages that are mentioned herein. There is a need to find a simple, efficient, and industrially economical method for the preparation of substituted anthranilic amide compounds. Accordingly, the present invention provides a facile, environment-friendly, and cost-efficient method for the preparation of substituted anthranilic amides and respective intermediates thereof, based on readily available starting materials.OBJECTIVE OF THE INVENTION:

[0016] The objective of the present invention is to provide a method for the synthesis of N-substituted anthranilic amides of formula (I) or its salts thereof.

[0017] Another objective of the present invention is to provide a method for the synthesis of the compounds of formula (VI) and compounds of formula (V).

[0018] Yet another objective of the present invention is to provide a simple, environment-friendly and cost-effective method for the synthesis of anthranilic diamides of formula (A), based on readily available starting materials.SUMMARY OF THE INVENTION:

[0019] The main objective of the present invention is to provide an industrially amenable and convenient method for the preparation of anthranilic amides of formula (I).

[0020] Surprisingly, the present invention provides a solution to this objective by providing a novel process that allows the preparation of anthranilic amides, overcoming at least one of the shortcomings of the processes described in the prior art.

[0021] Accordingly, in the first aspect, the present invention provides a novel process for preparing a compound of formula (I),formula (I) wherein,R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and n represents integer selected from 0-4; comprising the steps of:A. preparing isatin of formula (VI),formula (VI) wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; and n represents an integer selected from 0-4; by reacting a mixture comprising of, i. oxime derivative of formula (IV)wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; and n represents an integer selected from 0-4;Re is selected from H or Ci to Cf> alkyl; and ii. cyclizing reagent, wherein the cyclizing reagent is a mixture of two or more acids, iii. optionally in the presence of a solvent; andB. obtaining a compound of formula (I) by reacting a mixture comprising of, i. isatin of formula (VI) obtained in step Aformula (VI) wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3- Cs cycloalkyl; and n represents an integer selected from 0- 4; ii. a base; iii. optionally in the presence of a solvent; iv. an amine of formula (IX) or salt thereof;H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; v. an oxidizing agent; wherein said method optionally comprising the step of;halogenating the isatin of formula (VI), wherein at least one R is hydrogen with a suitable halogenation reagent, optionally in the presence of a suitable solvent to obtain halogenated isatins of formula (VI).

[0022] In a second aspect, the present invention relates to a method for the preparation of a compound of formula (Aa) or salts thereof;Formula (Aa) wherein,R represents R1, R2or R3, R1, R2, R3are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from the group consisting of hydrogen, Ci-Ce alkyl, C3-C6 cycloalkyl, C3-C6 cycloalkyl-Ci-C4 alkyl;R5is selected from the group comprising of halogen, C1-C4 alkyl, C1-C4 haloalkyl, CHF2, CF3, C1-C4 alkoxy, OCHF2, OCH2CF3,heterocyclyl; wherein -A- is selected from the group comprising of a direct bond, CHR6, -O- or -S-; and said heterocyclyl may optionally be substituted with one or more group selected from hydrogen, halogen, cyano, C1-C4 alkyl or C1-C4 haloalkyl;R6is selected from the group comprising of hydrogen, halogen, cyano, C1-C4 alkyl or C1-C4 haloalkyl; andX represents halogen;comprising the step of reacting a substituted anthranilic amide of formula (I), wherein the anthranilamide of formula (I) is (IA),wherein,R1, R2, R3are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-C6haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkylR4is selected from the group consisting of hydrogen, Ci-Ce alkyl, C3-C6 cycloalkyl, C3-C6 cycloalkyl-Ci-C4 alkyl; and n represents an integer selected from 0-4; with a pyrazole acid of formula (B),wherein W is OH, Cl, O-C1-C4 alkyl, O-C(O)Ci-C4 alkyl or imidazolyl;R5is selected from the group comprising of halogen, C1-C4 alkyl, C1-C4 haloalkyl, CHF2, CF3, C1-C4 alkoxy, OCF2H, OCH2CF3,heterocyclyl; wherein -A- is selected from the group comprising of direct bond, CHR6, - O- or -S-; and said heterocyclyl may optionally be substituted with one or more group selected from hydrogen, halogen, cyano, C1-C4 alkyl or C1-C4 haloalkyl;R6is selected from the group comprising of hydrogen, halogen, cyano, C1-C4 alkyl or C1-C4 haloalkyl andX represents halogen; in the presence of a coupling reagent, a suitable solvent, and optionally in the presence of a base, according to the following reaction scheme as depicted below,wherein, the compound of formula (I) is prepared comprising the steps of:A. preparing isatin of formula (VI)formula (VI) wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; and n represents an integer selected from 0-4; by reacting a mixture of, i. oxime derivative of formula (IV)wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, and n represents an integer selected from 0-4;wherein Re is selected from H or C1-C4 alkyl; and ii. cyclizing reagent, wherein the cyclizing reagent is a mixture of two or more acids, iii. optionally in the presence of a solvent, andB. obtaining a compound of formula (I) by reacting a mixture of, i. isatin of formula (VI) obtained in step Aformula (VI) wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, and n represents an integer selected from 0-4; ii. a base; iii. optionally in the presence of a solvent; iv. an amine compound of formula (IX) or salt thereof ,H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; v. an oxidizing agent; wherein said method optionally comprising the step of; halogenating the isatin of formula (VI) wherein at least one R is hydrogen with a suitable halogenation reagent, optionally in the presence of a suitable solvent to obtain halogenated isatins of formula (VI).DETAILED DESCRIPTION OF THE INVENTIONGENERAL DEFINITIONS

[0023] The definitions provided herein for the terminologies used in the present disclosure are for illustrative purpose only and in no manner limit the scope of the present invention disclosed in the present disclosure.

[0024] As used herein, the terms “comprises”, “comprising”, “includes”, “including”, “has”, “having”, “contains”, “containing”, “characterized by” or any other variation thereof, are intended to cover a non-exclusive inclusion, subject to any limitation explicitly indicated. For example, a composition, mixture, process or method that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, mixture, process or method.

[0025] The transitional phrase “consisting of’ excludes any element, step or ingredient not specified. If in the claim, such would close the claim to the inclusion of materials other than those recited except for impurities ordinarily associated therewith. When the phrase “consisting of’ appears in a clause of the body of a claim, rather than immediately following the preamble, it limits only the element set forth in that clause; other elements are not excluded from the claim as a whole.

[0026] The transitional phrase “consisting essentially of’ is used to define a composition or method that includes materials, steps, features, components or elements, in addition to those literally disclosed, provided that these additional materials, steps, features, components or elements do not materially affect the basic and novel character! stic(s) of the claimed invention. The term “consisting essentially of’ occupies a middle ground between “comprising” and “consisting of’.

[0027] Further, unless expressly stated to the contrary, “or” refers to an inclusive “or” and not to an exclusive “or”. For example, a condition A “or” B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

[0028] Also, the indefinite articles “a” and “an” preceding an element or component of the present invention are intended to be non-restrictive regarding the number of instances (i.e. occurrences) of the element or component. Therefore “a” or “an” should be read to include one or at least one, and the singular word form of the element or component also includes the plural unless the number is obviously meant to be singular.

[0029] Carbon-based radical refers to a monovalent molecular component comprising a carbon atom that connects the radical to the remainder of the chemical structure through a single bond. Carbon-based radicals can optionally comprise saturated, unsaturated and aromatic groups, chains, rings and ring systems, and heteroatoms. Although carbon-based radicals are not subject to any particular limit in size, in the context of the present invention they typically comprise 1 to 16 carbon atoms and o to 3 heteroatoms. Of note are carbon-based radicals selected from Ci- Ce alkyl, Ci-C6haloalkyl and phenyl optionally substituted with 1-3 substituents selected from C1-C3 alkyl, halogen and nitro.

[0030] The meaning of various terms used in the description shall now be illustrated.

[0031] The term “alkyl”, used either alone or in compound words such as“alkylthio” or “haloalkyl” or -N(alkyl) or alkylcarbonylalkyl or alkylsuphonylamino includes straight-chain or branched Ci to Cf> alkyl. Representative examples of alkyl include methyl, ethyl, propyl, 1 -methylethyl, butyl, 1 -methylpropyl, 2-methylpropyl, 1,1 -dimethylethyl, pentyl, 1 -methylbutyl, 2-methylbutyl, 3 -methylbutyl, 2,2-dimethylpropyl, 1 -ethylpropyl, hexyl, 1,1- dimethylpropyl, 1,2-dimethylpropyl, 1 -methylpentyl, 2-methylpentyl, 3- methylpentyl, 4-methylpentyl, 1,1 -dimethylbutyl, 1,2-dimethylbutyl, 1,3- dimethylbutyl, 2,2-dimethylbutyl, 2,3 -dimethylbutyl, 3, 3 -dimethylbutyl, 1- ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1 -ethyl- 1- methylpropyl and l-ethyl-2-methylpropyl or the different isomers. If the alkyl is at the end of a composite substituent, as, for example, in alkylcycloalkyl, the part of the composite substituent at the start, for example the cycloalkyl, may be mono- or polysubstituted identically or differently and independently by alkyl. The same alsoapplies to composite substituents in which other radicals, for example alkenyl, alkynyl, hydroxyl, halogen, carbonyl, carbonyloxy and the like, are at the end.

[0032] The term “cycloalkyl” means alkyl closed to form a ring. Representative examples include, but are not limited to cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl. This definition also applies to cycloalkyl as a part of a composite substituent, for example cycloalkylalkyl etc., unless specifically defined elsewhere.

[0033] The term “alkoxy” used either alone or in compound words included Ci to Ge alkoxy. Non limiting examples of alkoxy include methoxy, ethoxy, propoxy, 1 -methylethoxy, butoxy, 1 -methylpropoxy, 2-methylpropoxy, 1,1- dimethylethoxy, pentoxy, 1 -methylbutoxy, 2 -methylbutoxy, 3 -methylbutoxy, 2,2- dimethylpropoxy, 1 -ethylpropoxy, hexoxy, 1,1 -dimethylpropoxy, 1,2- dimethylpropoxy, 1 -methylpentoxy, 2-methylpentoxy, 3-methylpentoxy, 4- methylpentoxy, 1,1 -dimethylbutoxy, 1,2 -dimethylbutoxy, 1,3-dimethylbutoxy, 2,2- dimethylbutoxy, 2,3 -dimethylbutoxy, 3, 3 -dimethylbutoxy, 1 -ethylbutoxy, 2- ethylbutoxy, 1,1,2-trimethylpropoxy, 1,2,2-trimethylpropoxy, 1 -ethyl- 1- methylpropoxy and l-ethyl-2-methylpropoxy and the different isomers. This definition also applies to alkoxy as a part of a composite substituent, for example haloalkoxy, alkynylalkoxy, etc., unless specifically defined elsewhere.

[0034] The term "hydroxy" means -OH.

[0035] The term "halogen", either alone or in compound words such as "haloalkyl", includes fluorine, chlorine, bromine or iodine. Further, when used in compound words such as "haloalkyl", said alkyl may be partially or fully substituted with halogen atoms which may be the same or different.

[0036] The term "halogen", either alone or in compound words such as "haloalkyl", includes fluorine, chlorine, bromine or iodine. Further, when used in compound words such as "haloalkyl", said alkyl may be partially or fully substituted with halogen atoms which may be the same or different. Non-limiting examples of "haloalkyl" include chloromethyl, bromomethyl, dichloromethyl, trichloromethyl, fluoromethyl, difluoromethyl, trifluoromethyl, chlorofluoromethyl, dichlorofluoromethyl, chlorodifluoromethyl, 1 -chloroethyl, 1 -bromoethyl, 1- fluoroethyl, 2-fluoroethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl, 2-chloro-2-fluoroethyl, 2-chloro-2,2-difluoroethyl, 2,2-dichloro-2-fluoroethyl, 2,2,2- trichloroethyl, pentafluoroethyl, l,l-dichloro-2,2,2-trifluoroethyl, and 1,1,1- trifluoroprop-2-yl. This definition also applies to haloalkyl as a part of a composite substituent, unless specifically defined elsewhere.

[0037] The term "hetero" in connection with rings refers to a ring in which at least one ring atom is not carbon and which can contain 1 to 4 heteroatoms independently selected from the group consisting of nitrogen, oxygen and sulfur, provided that each ring contains no more than 4 nitrogen, no more than 2 oxygen and no more than 2 sulfur.

[0038] The term "aromatic" indicates that the Huckel rule is satisfied and the term "non-aromatic" indicates that the Huckel rule is not satisfied.

[0039] The term "heterocycle" or "heterocyclic" or "heterocyclyl" includes "aromatic heterocycle" or "heteroaryl bicyclic ring system" and "nonaromatic heterocycle " or polycyclic or bicyclic (spiro, fused, bridged, non-fused) ring compounds in which ring may be aromatic or non-aromatic, wherein the heterocycle ring contains at least one heteroatom selected from N, O, S(0)o-2, and / or C ring member of the heterocycle may be replaced by C(=O) and C(=S).

[0040] The term "non-aromatic heterocycle" or "non-aromatic heterocyclic" means three- to ten-membered, preferably three- to six-membered, saturated or partially unsaturated heterocycle containing one to four heteroatoms, selected from the group of oxygen, nitrogen and sulphur; mono, bi- or tricyclic heterocycles which contain, in addition to carbon ring members, one to three nitrogen atoms and / or one oxygen or sulphur atom or one or two oxygen and / or sulphur atoms; if the ring contains more than one oxygen atom, they are not directly adjacent; for example (but not limited to) oxetanyl, thietanyl, oxiranyl, aziridinyl, azetidinyl, tetrahydrofuranyl, tetrahydro thienyl, pyrrolidinyl, isoxazolidinyl, isothiazolidinyl, pyrazolidinyl, oxazolidinyl, thiazolidinyl, imidazolidinyl, oxadiazolidinyl, thiadiazolidinyl, triazolidinyl, dihydrofuryl, dihydrothienyl, pyrrolinyl, isoxazolinyl, isothiazolinyl, dihydropyrazolyl, dihydrooxazolyl, dihydrothiazolyl, piperidinyl, pyrazynyl, morpholinyl, thiomorphlinyl, 1,3-dioxany, tetrahydropyranyl, tetrahydro thienyl; wherein these rings are attached to the skeleton via one of the carbon or nitrogen of said rings. This definition also appliesto heterocyclyl as a part of a composite substituent, for example heterocyclylalkyl etc., unless specifically defined elsewhere.

[0041] The term "heteroaryl" or "aromatic heterocyclic" means 5 - membered, fully unsaturated monocyclic ring system containing one to four heteroatoms selected from the group of oxygen, nitrogen and sulphur; if the ring contains more than one oxygen atom, they are not directly adjacent; 5 -membered heteroaryl containing one to four nitrogen atoms or one to three nitrogen atoms and one sulphur or oxygen atom; 5-membered heteroaryl groups which, in addition to carbon atoms, may contain one to four nitrogen atoms or one to three nitrogen atoms and one sulphur or oxygen atom as ring members, for example (but not limited thereto) furyl, thienyl, pyrrolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl; wherein these rings are attached to the skeleton via one of the carbon or nitrogen of said rings,

[0042] To achieve at least one of the above defined objectives, the present invention is described in the following embodiments.Embodiment-001: The present invention provides a method for the synthesis of compounds of formula (I) from substituted oxime derivatives of formula (IV),formula (I) wherein,R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; andn represents an integer selected from 0-4; comprising the steps of:A. preparing isatin of formula (VI),formula (VI) wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; and n represents an integer selected from 0-4; by reacting a mixture of, i. oxime derivatives of formula (IV)wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, n represents an integer selected from 0-4; and Re is selected from H or Ci to C4 alkyl; and ii. cyclizing reagent, wherein the cyclizing reagent is a mixture of two or more acids; iii. optionally in the presence of a solvent; andB. preparing a compound of formula (I) by reacting a mixture of, i. isatin of formula (VI) obtained from step Aformula (VI) wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, n represents an integer selected from 0-4; ii. a base; iii. optionally in the presence of a solvent; iv. an amine of formula (IX) or salt thereof;H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and v. an oxidizing agent.Embodiment-OOIA: The present invention provides a method for the synthesis of compounds of formula (IA) from substituted oxime derivatives of formula (IVA),formula (IA) wherein,R1, R2, R3are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl; and R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; comprising the steps of:A. preparing an isatin of formula (VIA)formula (VIA) wherein R1, R2and R3is selected from hydrogen, halogen, C1-C12 alkyl, Ci- C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; by reacting a mixture of, i. oxime derivative of formula (IVA)wherein,R1, R2, R3are independently selected from hydrogen, halogen, Ci- Ce alkyl, Ci-C6haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3- Cs cycloalkyl, and Re is selected from H or Ci to C4 alkyl; ii. cyclizing reagent, wherein the cyclizing reagent is a mixture of two or more acids; optionally in the presence of a solvent; and B. preparing a compound of formula (IA) by reacting a mixture of; i. isatin compound of formula (VIA)wherein R1, R2and R3is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; ii. a base, iii. optionally in the presence of a solvent; iv. an amine compound of formula (IX) or salt thereof ,H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; v. an oxidizing agent.Embodiment-00 IB: The present invention provides a method for the synthesis of compounds of formula (IB) from substituted oxime derivatives of formula (IVB),formula (IB) wherein,R1and R2are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and X = Cl, Br, or I; comprising the steps of:A. preparing an isatin of formula (VIB)formula (VIB) wherein R1and R2are independently selected from hydrogen, halogen, Ci-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; wherein X = Cl, Br, or I; by reacting a mixture of, i. oxime derivatives of formula (IVB)wherein,R1and R2are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-C6haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl; X = Cl, Br or I; Re is selected from H or Ci to C4 alkyl; and ii. cyclizing reagent, wherein the cyclizing reagent is a mixture of two or more acids; optionally in the presence of a solvent; andB. preparing a compound of formula (IB)formula (IB)wherein,R1and R2are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-C6haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and X = Cl, Br, or I; by reacting a mixture of, i. isatin compound of formula (VIB) obtained in step-A;formula (VIB) wherein R1and R2are independently selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; and wherein X = Cl, Br, or I. ii. a base; iii. optionally in the presence of a solvent; iv. an amine compound of formula (IX) or salt thereof,H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and v. an oxidizing agent.Embodiment-001C: The present invention provides a method for the synthesis of compounds of formula (IB) from substituted oxime derivatives of formula (IVC),formula (IB) wherein,R1and R2are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-C6haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and X = Cl, Br, or I, comprising the steps of:A. preparing an isatin of formula (VIB)formula (VIB) wherein R1and R2are independently selected from hydrogen, halogen, Ci- C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; wherein X = Cl, Br, or I; by reacting a mixture of, i. oxime derivatives of formula (IVC)wherein,R1and R2are selected from hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl; Re is selected from H or Ci to C4 alkyl; and ii. cyclizing reagent, wherein the cyclizing reagent is a mixture of two or more acids, and iii. optionally in the presence of a solvent; and vi. halogenating the isatin of formula (VIC), obtained in the above reaction with a halogenation reagent to obtain isatin of formula VIB;wherein R1and R2are independently selected from hydrogen, halogen, Ci- Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl; and X = Cl, Br, or I;B. preparing a compound of formula (IB) by reacting a mixture of, i. isatin compound of formula (VIB) obtained in step-A;formula (VIB) wherein R1and R2are selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; and wherein X = Cl, Br, or I; ii. a base; iii. optionally in the presence of a solvent;iv. an amine compound of formula (IX) or salt thereof ,H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; v. an oxidizing agent.Embodiment-00 ID: The present invention provides a method for the synthesis of compounds of formula (IB) from substituted oxime derivatives of formula (IVC),formula (IB) wherein,R1and R2are independently selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; andX = Cl, Br or I; comprising the steps of:A. preparing isatin of formula (VIC)Formula (VIC) by reacting a mixture of, i. oxime of formula (IVC)wherein R1and R2are independently selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, and Re is selected from H or Ci to C4alkyl; ii. cyclizing reagent, wherein the cyclizing reagent is a mixture of two or more acids; iii. optionally in the presence of a solvent; andB. preparing a compound of formula (IC)wherein,R1and R2are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; by reacting a mixture of, i. isatin of formula (VIC) obtained from step AFormula (VIC) wherein R1and R2are selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; ii. a base; iii. optionally in the presence of a solvent; iv. an amine of formula (IX) or salt thereof;H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and v. an oxidizing agent, to obtain a compound of formula (IC),C. preparing a compound of formula (IB) from a compound of formula (IC) obtained from step-B, by halogenating the compound of formula (IC) using a suitable halogenation reagent to obtain a compound of formula (IB).Embodiment-OOIE: The present invention provides a method for the synthesis of compounds of formula (IB’) from substituted oxime of formula (IVC’),formula (IB’) wherein,R1are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and X = Cl, Br, or I, comprising the steps of:A. preparing an isatin of formula (VIC’)formula (VIC’) wherein R1is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; by reacting a mixture of, i. oxime derivatives of formula (IVC’)wherein,T1R1is selected from hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci- Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl; andRe is selected from H or Ci to C4 alkyl; ii. cyclizing reagent, wherein the cyclizing reagent is a mixture of two or more acids, optionally in the presence of a solvent to obtain compound of formula (VIC’)B. preparing a compound of formula (IC’),formula (IC’) wherein,R1are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; by reacting a mixture of, i. isatin compound of formula (VIC’) obtained in step-A; ii. a base; iii. optionally in the presence of a solvent; iv. an amine compound of formula (IX) or salt thereof ,H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl,C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; v. an oxidizing agent; to obtain compound of formula (IC),C. preparing a compound of formula (IB’) from compound of formula (IC’) obtained from step-B, by halogenating the compound of formula (IC’) using a suitable halogenation reagent to obtain compound of formula (IB’).Embodiment-002: According to another embodiment, the present invention provides a method for the synthesis of compounds of formula (I) from substituted oxime derivatives of formula (IV),formula (I) wherein,R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, Ci- C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and n represents integer selected from 0-4; comprising the steps of:A. cyclizing the compound of formula (IV) with a cyclizing reagent to obtain isatin of formula (VI);wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; Re is selected from H or Ci to C4 alkyl; and n represents integer selected from 0-4; wherein the cyclizing reagent is a mixture of two or more acids;B. preparing the amide of formula (I) by,(B-a). forming a mixture comprising of: i. isatin of formula (VI) or salt thereof,formula (VI) wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, and n represents integer selected from 0-4; ii. a base; and iii. optionally in the presence of a solvent;(B-b). introducing an amine compound of formula (IX) or salt thereof ,H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; into the mixture,(B-c) introducing an oxidizing agent into the mixture.Embodiment-002A: According to another embodiment, the present invention provides a method for the synthesis of compounds of formula (IA) from substituted oxime derivatives of formula (IVA),formula (IA) wherein,R1, R2, R3are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-C6haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl; andR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; comprising the steps of: A. preparing isatin of formula (VIA),wherein,R1, R2, and R3are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl; by cyclizing the compound of formula (IVA) with a cyclizing reagent to obtain isatin of formula (VIA);wherein R1, R2, R3are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-C6haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl, and wherein Re is selected from H or Ci to C4 alkyl; and wherein the cyclizing reagent is a mixture of two or more acids;B. preparing the amide of formula IA,formula (IA) wherein,R1, R2, and R3are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl; andR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; by(B-a). forming a mixture comprising of i. isatin of formula (VIA) or salt thereof,formula (VIA) wherein R1, R2and R3are independently selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; ii. a base; andiii. optionally in the presence of a solvent;(B-b). introducing an amine compound of formula (IX) or salt thereof ,H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; into the mixture,(B-c) introducing an oxidizing agent into the mixture.Embodiment-002B: According to another embodiment, the present invention provides a method for the synthesis of compounds of formula (IB) from substituted oxime derivatives of formula (IVB),formula (IB) wherein,R1and R2are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and X = Cl, Br, or I, comprising the steps of:A. preparing an isatin of formula (VIB),formula (VIB) wherein R1and R2are independently selected from hydrogen, halogen, Ci-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; and wherein X = Cl, Br, or I; by cyclizing the compound of formula (IVB) with a cyclizing reagent to obtain isatin of formula (VIB);wherein R1and R2are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl,X = Cl, Br, or I; Re is selected from H or Ci to C4 alkyl; and wherein the cyclizing reagent is a mixture of two or more acids; B. preparing the amide of formula IB by,(B-a). forming a mixture comprising of i. isatin of formula (VIB) or salt thereof,formula (VIB)wherein R1and R2are independently selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; and wherein X = Cl, Br, or I; ii. a base; and iii. optionally in the presence of a solvent;(B-b). introducing an amine compound of formula (IX) or salt thereof ,H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; into the mixture,(B-c) introducing an oxidizing agent into the mixture.Embodiment-002C: According to another embodiment, the present invention provides a method for the synthesis of compounds of formula (IB) from substituted oxime derivatives of formula (IVC),formula (IB) wherein,R1and R2are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and X = Cl, Br, or I;comprising the steps of:A. preparing an isatin of formula (VIB),formula (VIB) wherein R1and R2are independently selected from hydrogen, halogen, Ci-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; by cyclizing the compound of formula (IVC) with a cyclizing reagent to obtain isatin of formula (VIC);wherein R1and R2are independently selected from hydrogen, halogen, Ci- C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; Re is selected from H or Ci to C4 alkyl; wherein the cyclizing reagent is a mixture of two or more acids, and halogenating the isatin of formula VIC to obtain isatin of formula VIB ;B. preparing the amide of formula IB by, (B-a). forming a mixture comprising of i. isatin of formula (VIB) or salt thereof,formula (VIB) wherein R1and R2are independently selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; ii. a base; iii. optionally in the presence of a solvent;(B-b) introducing an amine compound of formula (IX) or salt thereof ,H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; into the mixture,(B-c) introducing an oxidizing agent into the mixture.Embodiment-002D: The present invention provides a method for the synthesis of compounds of formula (IB) from substituted oxime derivatives of formula (IVC),formula (IB) wherein,R1and R2are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-C6haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and X = Cl, Br, or I, comprising the steps of:A. preparing an isatin of formula (VIC)formula (VIC) wherein R1and R2are independently selected from hydrogen, halogen, Ci- C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; by cyclizing the compound of formula (IVC) with a cyclizing reagent to obtain isatin of formula (VIC),wherein R1and R2are independently selected from hydrogen, halogen, Ci- C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, wherein the cyclizing reagent is a mixture of two or more acids;B. preparing a compound of formula (IC),formula (IC) wherein,R1and R2are independently selected from hydrogen, halogen, Ci- Ce alkyl, Ci-C6haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl;(B-a). forming a mixture comprising of i. isatin of formula (VIC) or salt thereof, obtained in step-A ii. a base; iii. optionally in the presence of a solvent;(B-b) introducing an amine compound of formula (IX) or salt thereof,H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; into the mixture,(B-c) introducing an oxidizing agent into the mixture.C. preparing a compound of formula (IB) from compound of formula (IC) obtained from step-B, by halogenating the compound of formula (IC) using a suitable halogenation reagent to obtain compound of formula (IB).Embodiment-003: According to another embodiment, the present invention provides a method for the synthesis of compounds of formula (I) from substituted oxime derivatives of formula (IV),formula (I) wherein,R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, Ci- C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and n represents integer selected from 0-4; comprising the steps of:A. Preparing an isatin of formula (VI),formula (VI) wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; and n represent an integer selected from 0-4; by cyclizing the compound of formula (IV) with a cyclizing reagent to obtain isatin of formula (VI);wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; Re is selected from H or Ci to C4 alkyl; n represents integer selected from 0-4; and wherein the cyclizing reagent is a mixture of two or more acids;B. preparing the amide of formula (I) by, (B-a). forming a mixture comprising of i. isatin of formula (VI) or salt thereof,formula (VI) wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; and n represents an integer selected from 0-4; ii. a base and optionally in the presence of solvent; to obtain a compound of formula (XI),formula (XI) wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; M+represent metal ion;wherein the compound of formula (XI) or salt thereof, was optionally isolated;(B-b) introducing an amine compound of formula (IX) or salt thereof ,H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; into the mixture, reacting the mixture, to obtain a compound of formula (XII) or salt thereof,formula (XII) wherein,R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and n represents integer selected from 0-4; wherein the compound of formula (XII) or salt thereof, was optionally isolated;(B-c) introducing an oxidizing agent to the mixture; and reacting the mixture.Embodiment-003A: According to another embodiment, the present invention provides a method for the synthesis of compounds of formula (IA) from substituted oxime derivatives of formula (IVA),formula (IA) wherein,R1, R2, R3are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-C6haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl; and R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; comprising the steps of:A. preparing isatin of formula (VIA),formula (VIA) wherein R1, R2, and R3are selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; by cyclizing the compound of formula (IVA) with a cyclizing reagent to obtain isatin of formula (VIA);wherein R1, R2, R3are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-C6haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl; Re is selected from H or Ci to C4 alkyl; and wherein the cyclizing reagent is a mixture of two or more acids;B. preparing the amide of formula (IA) by, (B-a). forming a mixture comprising of i. isatin of formula (VIA) or salt thereof,formula (VIA) wherein R1, R2, and R3are selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; ii. a base and optionally in the presence of solvent; to obtain a compound of formula (XIA),formula (XIA)wherein R1, R2and R3are selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; M+represent metal ion; wherein the compound of formula (XIA) or salt thereof, was optionally isolated;(B-b) introducing an amine compound of formula (IX) or salt thereof,H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; into the mixture, reacting the mixture, to obtain a compound of formula (XIIA) or salt thereof,formula (XIIA) wherein,Rx, R2and R3are selected from hydrogen, halogen, C1-C12 alkyl, Ci- C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; andwherein the compound of formula (XIIA) or salt thereof, was optionally isolated;(B-c) introducing an oxidizing agent to the mixture; and reacting the mixture.Embodiment-003B: According to another embodiment, the present invention provides a method for the synthesis of compounds of formula (IB) from substituted oxime derivatives of formula (IVB),formula (IB) wherein,R1and R2are selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and X = Cl, Br, or I; comprising the steps of:A. preparing isatin of formula (VIB) by, cyclizing the compound of formula (IVB) with a cyclizing reagent to obtain isatin of formula (VIB);wherein R1and R2are selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3- Cs cycloalkyl; Re is selected from H or Ci to C4 alkyl;X = Cl, Br OR I, and wherein the cyclizing reagent is a mixture of two or more acids;B. preparing the amide of formula IB by,(B-a). forming a mixture comprising of i. isatin of formula (VIB) or salt thereof,formula (VIB) wherein R1and R2are selected from hydrogen, halogen, Ci- C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; and X = Cl, Br, or I, ii. a base and optionally in the presence of solvent; to obtain a compound of formula (XIB),formula (XIB) wherein R1and R2is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; M+represent metal ion, X = Cl, Br, or I; and wherein the compound of formula (XIB) or salt thereof, was optionally isolated;(B-b) introducing an amine compound of formula (IX) or salt thereof ,H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; into the mixture, reacting the mixture, to obtain a compound of formula (XIIB) or salt thereof,formula (XIIB) wherein,R1and R2are selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; X = Cl, Br, OR I; and wherein the compound of formula (XIIB) or salt thereof, was optionally isolated;(B-c) introducing an oxidizing agent to the mixture; and reacting the mixture.Embodiment-003C: According to another embodiment the present invention provides a method for the synthesis of compounds of formula (IB) from substituted oxime derivatives of formula (IVC),formula (IB) wherein,R1is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, Ci- C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and X = Cl, Br, or I; comprising the steps of:A. preparing isatin of formula (VIB) by,(i) cyclizing the compound of formula (IVC) with a cyclizing reagent to obtain isatin of formula (VIC);(IVC) wherein R1is selected from hydrogen, halogen, C1-C12 alkyl, Ci- C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; Re is selected from H or Ci to C4 alkyl; and wherein the cyclizing reagent is a mixture of two or more acids; and(ii) halogenating the isatin of formula (VIC) to obtain isatin of formula (VIB);wherein R1is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, and wherein X = Cl, Br, or I. B. preparing the amide of formula I by;(B-a). forming a mixture comprising of i. isatin of formula (VIB) or salt thereof,formula (VIB) wherein R1is selected from hydrogen, halogen, C1-C12 alkyl,C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; and X = Cl, Br, or I; ii. a base and optionally in the presence of solvent; to obtain a compound of formula (XIB),formula (XIB) wherein R1is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; X = Cl, Br, OR I; andwherein the compound of formula (XIB) or salt thereof, was optionally isolated;(B-b) introducing an amine compound of formula (IX) or salt thereof ,H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; into the mixture, reacting the mixture, to obtain a compound of formula (XIIB) or salt thereof,formula (XIIB) wherein,R1is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and X = Cl, Br, OR I; and wherein the compound of formula (XIIA) or salt thereof, was optionally isolated;(B-c) introducing an oxidizing agent to the mixture; and reacting the mixture.Embodiment-003D: According to another embodiment the present invention provides a method for the synthesis of compounds of formula (IB) from substituted oxime derivatives of formula (IVD),formula (IB) wherein,R1and R2are independently selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and X = Cl, Br, or I; comprising the steps of:A. preparing isatin of formula (VID) by, cyclizing the compound of formula (IVD) with a cyclizing reagent to obtain isatin of formula (VID);wherein R1and R2are independently selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; Re is selected from H or Ci to C4 alkyl; and wherein the cyclizing reagent is a mixture of two or more acids; andB. preparing the amide of formula ID by;(B-a). forming a mixture comprising of i. isatin of formula (VID) or salt thereof,formula (VID) wherein R1and R2are independently selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; and X = Cl, Br, or I; ii. a base and optionally in the presence of solvent; to obtain a compound of formula (XID),formula (XID) wherein R1and R2are independently selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; X = Cl, Br, OR I; and wherein the compound of formula (XID) or salt thereof, was optionally isolated;(B-b) introducing an amine compound of formula (IX) or salt thereof,H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl,C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; into the mixture, reacting the mixture, to obtain a compound of formula (XIID) or salt thereof,formula (XIID) wherein,R1and R2are independently selected from hydrogen, halogen, Ci- C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3- Cs cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and X = Cl, Br, or I; and wherein the compound of formula (XIID) or salt thereof, was optionally isolated;(B-c). introducing an oxidizing agent and HX into the mixture; and reacting the mixture; wherein X = Cl, Br, or I;C. preparing a compound of formula (IB) from compound of formula (IC) obtained from step-B, by halogenating the compound of formula (IC) using a suitable halogenation reagents to obtain compound of formula (IB).The embodiments 001, 001 (A, B, C, D, E), 002, 002 (A, B, C, D), 003, 003 (A, B, C, D) and 004 provide a method for the synthesis of compounds of formula I in two steps, i.e., step A and step B. Step B may further comprise the sub-steps of (B-a), (B-b), and (B-c). Step B can be performed by carrying out the sub-steps (B-a), (B-b), and (B-c) separately, or by combining sub-steps (B-a), (B-b) and (B-c) in a single step.Embodiment-004: According to another embodiment, the present invention provides a method for the synthesis of compounds of formula (ID) from substituted amide of formula (IB),formula (ID) wherein,R1and R2are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-C6haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; comprising the step of reacting a compound of formula IB with a source of CN“ ions;formula (IB) wherein,R1and R2are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; andX = Cl, Br, or I; wherein the compounds of formula (IB) are prepared from substituted oxime derivatives of formula (IVB) or (IVC) according to any of above embodiment.Embodiment-004A: According to another embodiment, the present invention provides a method for the synthesis of compounds of formula (ID) from substituted anthranilic amide of formula (IB),formula (ID) wherein,R1and R4are independently selected from C1-C12 alkyl; comprising the step of reacting a compound of formula IB with a source of CN ions;formula (IB) wherein,R1and R4are independently selected from Ci-Ce alkyl; and X = Cl, Br, or I. more preferably R1and R4= methyl.Embodiment-004B: The source of CN’ ions in carrying out the cyanation reactions mentioned in the present invention of embodiment-4 , 4A, 4B and 4C are selected from metal cyanide particularly, sodium cyanide (NaCN), potassium cyanide(KCN), copper(I)cyanide (CuCN), zinc(II) cyanide (Zn(CN)2), sodium ferrocyanide (Na4Fe(CN)e), Potassium hexacyanoferrate (III) (K3[Fe(CN)e]), Potassium hexacyanoferrate (II) (K4[Fe(CN)e]) preferably copper(I)cyanide (CuCN), or Potassium hexacyanoferrate (II) (K4[Fe(CN)e]).Embodiment-004C: The ligand used in carrying out the cyanation reactions mentioned in the present invention of embodiment-4, 4A, 4B and 4C are selected from 1,2-dimethylethylenediamine (DMEDA) , 1 -butyl- IH-imidazole, 2 -picoline, 3-picoline, 2,6-lutidine, 1 -methyl pyrolidine, or pyrolidine.Embodiment-004D: The catalyst used in carrying out the cyanation reactions mentioned in the present invention of embodiment-4, 4A, 4B and 4C are selected from copper salts such as copper (I) iodide (Cui), copper (I) chloride, copper (I) bromide, copper acetate.Embodiment-004E: The solvents useful in carrying out the reactions in cyanation reaction mentioned in the present invention of embodiment-4 , 4A, 4B and 4C are selected from. A,A-di methyl formamide, A-mcthyl-2-pyrrolidonc n-butanol, i- butanol, sec-butanol or tert-butanol.Embodiment-005: In another embodiment, the oxime of Formula IVF is formed by reacting the compound of Formula III and chloral hydrate and hydroxylamine in the presence of one or more suitable reagents including but not limiting to hydrochloric acid, sulfuric acid, acetic acid, trifluoroacetic acid, nitric acid and sodium sulphate and one or more solvent / s at a temperature in the range from 15 °C to 150 °C.(III) (IVF)wherein, R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, Ci- C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, and n represents an integer selected from 0-4.Embodiment-005A: In any of the above embodiments the oxime of Formula (IVF, IV) is converted into the compound of Formula (VI) by using mineral acid including but not limiting to sulfuric acid, hydrochloric acid and nitric acid and stirring within a temperature ranging from 0 °C to 150 °C.wherein Ris selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, Ci- C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; Re is selected from H or Ci to C4alkyl;Embodiment-005B: In one embodiment, the compound of formula (II) is converted to a compound of formula (IV) by reacting it with a hydroxyl amine in the presence of a suitable base and a suitable solvent, such as for instance isopropanol; as shown in the following Scheme:(II) (IV) wherein, R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, Ci- C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, X = Cl, Br or I, n represents an integer selected from 0-4, and Re = H or Ci-Ce alkyl.Embodiment-005C: In one embodiment, the compound of formula (II) is converted to a compound of formula (IVF) by reacting it with hydroxyl amine in the presence of a suitable base and a suitable solvent, such as for instance isopropanol; as shown in the following Scheme:(II) (IVF) wherein, R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, Ci- C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, X = Cl, Br or I, and n represents an integer selected from 0-4.Embodiment-005D: In an embodiment, compound of formula (III) is reacted with a compound of formula (XIII) or a compound of formula (XIV) to obtain a compound of formula (II)wherein, R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, Ci- C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, X = Cl, Br or I, and n represents an integer selected from 0-4.Embodiment-005E: In an embodiment, the compound of formula (III) is reacted with with a compound of formula (XV) or a compound of formula (XVI) to obtain a compound of formula (IVE)wherein, R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, Ci- C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, X = Cl, Br or I, and n represents an integer selected from 0-4.Embodiment-005F: In another embodiment, the present invention provides a method for obtaining compounds of formula (IVF) from compounds of formula (III) and (1), wherein, R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, and n represents an integer selected from 0-4; comprising the steps of:1. reacting glyoxalic acid with acetic anhydride at a temperature of 80-130 °C, optionally isolating the intermediate (2) which was further reacted with thionyl chloride to obtain a compound of formula (3);2. reacting the compound of formula (III) with the compound of formula (3), optionally isolating the intermediate compound of formula (XVII), to afford a compound of formula (IVF), optionally in the presence of a suitable base and a suitable solvent;Embodiment-005G: In another embodiment, the oxime of Formula IVF is formed by: reacting the compound of Formula III and chloral hydrate and hydroxyl amine in the presence of one or more suitable reagents including but not limiting to hydrochloric acid, sulfuric acid, acetic acid, trifluoroacetic acid, nitric acid and sodium sulphate and one or more solvent / s at a temperature in the range from 15 °C to 150 °C.(in) (IVF)wherein, R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, Ci- C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, and n represents an integer selected from 0-4;(OR) the compound of formula (II) is converted to a compound of formula (IVF) by reacting it with a hydroxyl amine in the presence of a suitable base and a suitable solvent, such as for instance isopropanol; as shown in the following Scheme:(II) (IVF) wherein, R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, Ci- C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, X = Cl, Br or I, and n represents an integer selected from 0-4.Embodiment-006: In another embodiment, the compound of formula (VI), is prepared:formula (VI) wherein, R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, Ci- C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, and n represents an integer selected from 0-4, by cyclizing the compound of formula (IVF) using a cyclizing reagent, wherein the cyclizing reagent is a mixture of two or more acids,wherein, R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, Ci- C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, and n represents an integer selected from 0-4, optionally in the presence of a solvent.Embodiment-007: In another embodiment, the present invention relates to a method for the preparation of a compound of formula (A) or salts thereof;Formula (A) wherein,R is selected from the group comprising of halogen, C1-C4 alkyl, C1-C4 haloalkyl and C3-C4-cycloalkyl;R4is selected from the group consisting of hydrogen, Ci-Ce alkyl, C3-C6 cycloalkyl, C3-C6 cycloalkyl-Ci-C4 alkyl;R5is selected from the group comprising of halogen, C1-C4 alkyl, C1-C4 haloalkyl, CHF2, CF3, C1-C4 alkoxy, OCHF2, OCH2CF3, or -A-C3-C5 heterocyclyl; wherein -A- is selected from the group comprising of a direct bond, CHR6, -O- or -S-; and said heterocyclyl may optionally be substituted with one or more group selected from hydrogen, halogen, cyano, C1-C4 alkyl or C1-C4 haloalkyl;R6is selected from the group comprising of hydrogen, halogen, cyano, C1-C4 alkyl or C1-C4 haloalkyl; andX represents Cl, Br, or I; comprising the step of reacting a substituted anthranilic amide of formula (I),wherein,R is selected from the group comprising of halogen, C1-C4 alkyl, C1-C4 haloalkyl and C3-C4-cycloalkyl;R4is selected from the group consisting of hydrogen, Ci-Ce alkyl, C3-C6 cycloalkyl, C3-C6 cycloalkyl-Ci-C4 alkyl; with a formula (B)wherein W is OH, Cl, O-C1-C4 alkyl, O-C(O)Ci-C4 alkyl or imidazolyl;R5is selected from the group comprising of halogen, C1-C4 alkyl, C1-C4 haloalkyl, CHF2, CF3, C1-C4 alkoxy, OCF2H, OCH2CF3, or -A-C3-C5 heterocyclyl; wherein -A- is selected from the group comprising of direct bond, CHR6, -O- or -S-; and said heterocyclyl may optionally be substituted with one or more group selected from hydrogen, halogen, cyano, C1-C4 alkyl or C1-C4 haloalkyl;R6is selected from the group comprising of hydrogen, halogen, cyano, C1-C4 alkyl or C1-C4 haloalkyl andX represents Cl, F, Br, or I; in the presence of a coupling reagent, a suitable solvent, and optionally in the presence of a base, according to the following reaction scheme as depicted below,wherein, the compound of formula (I) is prepared comprising the steps of:A. preparing isatin of formula (VI)formula (VI) wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; and n represents an integer selected from 0-4; by reacting a mixture of, i. oxime of formula (IVF)wherein, R is selected from hydrogen, halogen, C1-C12 alkyl, Ci- C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, and n represents an integer selected from 0-4, ii. cyclizing reagent, wherein the cyclizing reagent is a mixture of two or more acids, iii. optionally in the presence of a solvent, andB. obtaining a compound of formula (I) by reacting a mixture of, i. isatin of formula (VI) obtained in step Aformula (VI) wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; ii. a base; iii. optionally in the presence of a solvent; iv. an amine compound of formula (IX) or salt thereof ,H2N - R4formula (IX) whereinR4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; v. an oxidizing agent; wherein said method optionally comprising the step of: halogenating the isatin of formula (VI) wherein at least one R is hydrogen with a suitable halogenation reagent, optionally in the presence of a suitable solvent to obtain halogenated isatins of formula (VI).The compounds of formula (B) can be obtained by either of the processes disclosed in W02003015518, W020030155519, WO2011157664 and W02013030100.Embodiment-008: In another embodiment, the present invention relates to method further comprises the step of preparation of a compound of formula (Aa) or of salts thereof;Formula (Aa) wherein,R represents R1, R2or R3, R1, R2, R3are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from the group consisting of hydrogen, Ci-Ce alkyl, C3-C6 cycloalkyl, C3-C6 cycloalkyl-Ci-C4 alkyl;R5is selected from the group comprising of halogen, C1-C4 alkyl, C1-C4 haloalkyl, CHF2, CF3, C1-C4 alkoxy, OCHF2, OCH2CF3,heterocyclyl; wherein -A- is selected from the group comprising of a direct bond, CHR6, -O- or -S-; and said heterocyclyl may optionally be substituted with one or more group selected from hydrogen, halogen, cyano, C1-C4 alkyl or C1-C4 haloalkyl;R6is selected from the group comprising of hydrogen, halogen, cyano, Ci- C4 alkyl or C1-C4 haloalkyl; X represents Cl, Br or I; comprising the step of reacting a substituted anthranilic amide of formula (I), wherein the anthranilamide of formula (I) is (IA),wherein, with a pyrazole compound of formula (B),wherein W is OH, Cl, O-C1-C4 alkyl, O-C(O)Ci-C4 alkyl or imidazolyl; in the presence of a coupling reagent, a suitable solvent, and optionally in the presence of a base, according to the following reaction scheme as depicted below.Embodiment-009: In one embodiment, compounds of formula (VIC’) can be converted to compounds of formula (VICC) by reacting them with an appropriate halogenation reagent such as for instance chlorine gas; as shown in the following Scheme:Embodiment-010: The method according to any of the above embodiments comprising optionally halogenating the isatins of formula (VI), (VIA), and (VIC) with a suitable halogenation reagent, optionally in the presence of a suitable solvent to obtain halogenated isatins of formula (VI), (VIA), and (VIB).Embodiment-011: According to any of the above embodiments, halogenations as described in the present invention are carried out in the presence of suitable halogenation reagents which include, but are not limited to, HX, NaX, KX, CuX2, MgX2, CsX, ZnX2, SOC12, SO2C12.COC12, X2, C(=O)(OC13)2, t-BuOCl, NaOCl, HX + H2O2, A-halosuccinamides, methane sulfonyl chloride, POX3, PX3, PX5 or metal halides; wherein X is Cl, Br, I or F. Preferably, the applied halogenation agent for this purpose is chlorine gas.Embodiment-OIOA: According to any of the above embodiments, halogenations as described in step-C, and (A-c) mentioned in the present invention is carried out in the presence of suitable halogenation reagents which selected from X2, particularly chlorine or bromine gas; SOC12, SO2C12, or HX+H2O2wherein X represents Cl or Br.Embodiment-01 OB: In one embodiment, compounds of formula (IC) can be converted to compounds of formula (IB) by reacting them with an appropriate halogenation reagent such as chlorine or bromine gas; H2O2and HC1 or H2O2and HBr; as shown in the following Scheme:Embodiment-0 IOC: In an embodiment, the solvents useful in carrying out the reactions in step-C, and (A-c) mentioned in the present invention are selected from acetic acid, hydrochloric acid or hydrobromic acid.Embodiment-012: According to any of the above embodiments the anthranilic amides of formula (I), (IA), (IB), (ID) in step B are prepared without isolating any of the intermediates obtained of steps A and B.Embodiment-013: According to any of the above embodiments the isatin of formula (VI), (VIA), (VIB), (VIC), (VID) in step A, and the anthranilic amide of formula I, IA, IB, IC, ID in step B are prepared by optionally isolating one or more intermediates formed during the reaction.Embodiment-014: According to any of the above embodiments, the reagents for cyclizing compounds of formula (IV), (IVA), (IVB), (IVC), (IVE), (IVF) useful in the present invention is a mixture of two or more acids selected from the group consisting of hydrochloric acid, hydrobromic acid, sulfuric acid, formic acid, acetic acid, trifluoroacetic acid, propionic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, acidic ion-exchange resin, AIX3, BX3, FcXs. ZnX2, GaXs, InXs, TiX4, BiX,, 86X3, SnX2, SnX4, SiX4, POX3, and hypovalent Lewis acids, wherein X = F, Cl, Br and I.Embodiment-013 A: According to any of the above embodiments, the reagents for cyclizing compounds of formula (IV), (IVA), (IVB), (IVC), (IVE), (IVF) useful in the present invention is a mixture of two or more acids selected from the group consisting of sulfuric acid, formic acid, trifluoroacetic acid, methanesulfonic acid, and POX3, wherein X = Cl, or Br.Embodiment-015: According to any of the above embodiments, a base is an inorganic base and is selected from alkali metal and alkaline earth metal hydroxides, alkali metal and alkaline earth metal carbonates, alkali metal and alkaline earth metal oxides, alkali metal and alkaline earth metal phosphates and any combination thereof, each alkali metal being independently selected from lithium, sodium and potassium and each alkaline earth metal being independently selected from calcium, magnesium and barium.Embodiment-016: According to any of the above embodiments said inorganic base is selected from sodium carbonate (Na2CC>3), calcium carbonate (CaCCE), cesium carbonate (CS2CO3), lithium carbonate (Li2CO3), potassium carbonate (K2CO3), lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), cesium hydroxide (CsOH), calcium hydroxide (Ca(0H)2), sodiumdiphosphate (Na2HPO4), sodium phosphate (NasPCU), potassium diphosphate (K2HPO4), and potassium phosphate (K3PO4).Embodiment-017: According to any of the above embodiments an oxidizing agent is selected from oxygen, chlorine, sodium hypochlorite, chromium trioxide, 3- chloroperoxybenzoic acid, hydrogen peroxide, tert-butyl hydroperoxide, peroxyacetic acid, potassium peroxymonosulfate, potassium permanganate, and combinations thereof.Embodiment-018: According to any of the above embodiments there is provided a method wherein, said inorganic base is selected from sodium hydroxide and said oxidizing agent is selected from hydrogen peroxide.Embodiment-019: According to any of the above embodiments, cyclization of compounds of formula (IV), (IVA), (IVB), (IVC), (IVE), (IVF) (1 molar equivalent) in step [A] is conducted using from 1 to 20, 1 to 15, 1 to 10, 1 to 7, 1 to 5 molar equivalents of the mixture of acids. If one of the acid in the above mixture is referred to as acid A and the other acid is referred to as acid B, then the two acids (Acid A: Acid B) can be mixed in a molar ratio in the range of 1:100 to 100:1, 1:50 to 50:1, 1:25 to 25:1, 1:10 to 10:1 or 1:5 to 5:1. The cyclizing in sub-step [A-b], is conducted at varying temperatures in the range of 0 to 200 °C, 10 to 180 °C, 25 to 160 °C, 25 to 140 °C or 25 to 130 °C.Embodiment-020: According to any of the above embodiments, sub-step (B-a) for the conversion of compounds of formula (VI), (VIA), (VIB), (VIC), (VID) (1 molar equivalent) to compounds of formula (XI), (XIA), (XIB), (XIC), (XID) is conducted using from 1 to 20, 1 to 15, 1 to 10, 1 to 7, 1 to 5, 1 to 2, or 1 molar equivalents of a suitable base, at temperatures in the range of from 0 to 100 °C.Embodiment-021: According to any of the above embodiments the sub- step (B-b) for the conversion of compounds of formula (XI), (XIA), (XIB), (XIC), (XID) (obtained from 1 molar equivalent of compounds of formula (VI), (VIA), (VIB),(VIC), (VID)) to compounds of formula (XII), (XIIA), (XIIB), (XIIC), (XIID) is conducted using from 1 to 5, 1 to 4, 1 to 3, 1 to 2, or 1 molar equivalents of a suitable amine of formula (IX) H2N-R4.Embodiment-022: According to any of the above embodiments the sub-step (B- c) for the conversion of compounds of formula (XII), (XIIA), (XIIB), (XIIC), (XIID) (obtained from 1 molar equivalent of compounds of formula (VI), (VIA), (VIB), (VIC), (VID)) to compounds of formula (I, IA, IB, IC, ID) is conducted using from 1 to 20, 1 to 15, 1 to 10, 1 to 7, 1 to 5, 1 to 2 or 1 molar equivalents of a suitable oxidizing agent, at temperatures in the range of -40 to 50 °C. In any of the above embodiments, the reaction in step B, is conducted at various temperatures in the range of -40 to 50, -20 to 50, -10 to 30, 0 to 30 or 5 to 25 °C.Embodiment-023: According to any of the above embodiments the sub-step (B- c) for the conversion of compounds of formula (XII), (XIIA), (XIIB), (XIIC), (XIID) (obtained from 1 molar equivalent of compounds of formula (VI), (VIA), (VIB), (VIC), (VID)) to compounds of formula (I, IA, IB, IC, ID) is conducted using from 1 to 20, 1 to 15, 1 to 10, 1 to 7, 1 to 5, 1 to 2 or 1 molar equivalents of a suitable oxidizing agent, at temperatures in the range of -40 to 50 °C, along with an acid HX, wherein X = Cl, Br, or I. In any of the above embodiments, the reaction in step B, is conducted at various temperatures in the range of -40 to 150, -40 to 120, -40 to 100, -40 to 90 or -40 to 80 °C.Embodiment-024: According to any of the above embodiments, halogenation of isatins of formula (VIC) (1 molar equivalent) is conducted using from 1 to 20, 1 to 15, 1 to 10, 1 to 8, 1 to 5, 1 to 4, 1 to 3, 1 to 2, or 1 molar equivalents of the halogenation reagent. This halogenation reaction is conducted at temperatures in the range from 0 to 150, 10 to 100, 10 to 100, 10 to 75, 10 to 65, 10 to 55, or 10- 45 °C.Embodiment-025 : The optional solvents useful in carrying out the reaction steps mentioned in the present invention are selected from aliphatic hydrocarbons suchas hexane, heptane, octane, nonane, decane, dodecane, decaline and the like; alicyclic hydrocarbons such as cycloalkanes: cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, and the like; aromatic hydrocarbons such as toluene, xylene, mesitylene, benzene and the like; halogenated aromatic hydrocarbons as chlorobenzene, 1,2-dichlorobenzene, 1,3 -dichlorobenzene and the like; ethers such as diisopropyl ether, t-butyl methyl ether, tetrahydrofuran, 2- methyl tetrahydrofuran, dioxane, monoglyme, diglyme, methoxy-methane, methoxy-ethane, ethoxy-ethane, di-methoxyethane, di-ethoxyethane and the like; alcohols such as methanol, ethanol, n- or i-propanol, n-, i-, sec- or tert-butanol, ethanediol, propane- 1,2-diol, ethoxyethanol, methoxy ethanol, ketones such as acetone, ethyl methyl ketone, esters such as ethyl acetate and methyl acetate; halogenated hydrocarbons such as dichloromethane, chloroform, dichloroethane and the like; nitriles, such as acetonitrile, propionitrile; polar aprotic solvents such as A, A-dimcthy formamide, dimethyl sulfoxide, A-mcthyl-2-pyrrolidonc, 1,3- dimethyl-3,4,5,6-tetrahydro-2(lH)-pyrimidinone, hexamethylphosphortriamide, l,3-dimethyl-2-imidazolidinone and the like; water or mixtures thereof.Embodiment-024A: The preferred solvents useful in carrying out the oxime formation reaction mentioned in the present invention are selected from alcohols such as methanol, ethanol, n- or i-propanol, n-, i-, sec- or tert-butanol, ethanediol, as ethanol, n- or i-propanol, n-, i-, sec- or tert-butanol and ethanediol; more preferably a mixture of ethanol and water is perceived as useful.Embodiment-024B: The preferred solvent useful in carrying out the preparation of isatin (VI, VIA, VIB, VIC, VID) from oxime derivative (IV, IVA, IVB, IVC, IVD, IVE, IVF) is selected from dichloroethane toluene, xylene, chlorobenzene or 1,2- dichlorobenzene .Embodiment-024C: The reaction steps mentioned in the present invention can also be carried out in the absence of solvents.Embodiment-024D: The oximes of formula (IV, IVA, IVB, IVC, IVD, IVE, IVF) are converted to the isatins of formula (VI, VIA, VIB, VIC, VID) by using mineralacids selected from, but not limited to, sulfuric acid, hydrochloric acid and nitric acid, preferably sulfuric acid; usually under stirring or other means of mixing within a temperature ranging from 0 °C to 150 °C.Embodiment-024E: The compounds of formula (A) are obtained by reacting the compounds of formula (I) with the compounds of formula (B), wherein W is OH, using a suitable reagent such as SOCh, SO2CI2, COCI2, X2, C(=O)(OC13)2, chloramine-T, methane sulfonyl chloride, POX3, PX3, PX5 FeCE or metal halides; wherein X is Cl, Br.Embodiment-024F: The compounds of formula (A) are obtained by reacting the compounds of formula (I) with the compounds of formula (B), wherein W is Cl or O-C1-C4 alkyl, optionally using suitable reagents such as triethylamine, diisopropylamine, diisopropyl ethyl amine, pyridine, alkylated and dialkylated pyridines, dimethylamino pyridine, and the like, or of mixtures thereof.Embodiment-026: The solvents useful in carrying out the reactions in steps (B- a), and (B-b) mentioned in the present invention are selected from acetonitrile, ethers such as diisopropyl ether, t-butyl methyl ether, tetrahydrofuran, 2-methyl tetrahydrofuran, dioxane, monoglyme, diglyme, methoxy-methane, methoxyethane, ethoxy-ethane, di-methoxyethane, di-ethoxyethane and the like; water, and esters such as ethyl acetate and methyl acetate.Embodiment-027 : In an embodiment there are provided compounds of formula (I, IA, IB, IC, ID), wherein, R4is selected from hydrogen, methyl, ethyl, isopropyl, t-butyl, methyl cyclopropyl or ethyl cyclopropyl.Embodiment-028: In an embodiment the amine R4-NH2, useful in the present invention include methylamine, ethylamine, n-propylamine, isopropylamine, n- butylamine, sec-butyamine, isobutylamine, pentylamine and its primary amine isomers, hexylamine and its primary amine isomers, benzylamine, and cyclohexylamine .Embodiment-029: Yet another embodiment provides the compounds of formula (B), wherein, R5is selected from the group comprising of bromo, chloro, CF3Embodiment-030: According to any of the above embodiments, the present invention provides a method for the synthesis of compounds of formula (I), wherein the compounds of formula (I) are selected from:Embodiment-031: In another embodiment the compound of formula (A) comprises of chlorantraniliprole, cyantraniliprole, cyclaniliprole, tetraniliprole, tetra-chlorantraniliprole, bromantraniliprole or fluchlordiniliprole.

[0043] Any person skilled in the art knows the best work-up of the reaction mixtures after the end of the respective reactions. In one embodiment, the work-up is usually carried out by isolation of the product by filtration, and optionally washing with solvent, further optionally drying of the product if required.

[0044] The process steps according to the invention are generally carried out under atmospheric pressure. Alternatively, however, it is also possible to work under increased or reduced pressure.

[0045] Without further elaboration, it is reasonable to believe that any person skilled in the art who is using the preceding description can utilize the present invention to its fullest extent. The following examples are therefore to be interpreted as merely illustrative and not limiting of the disclosure in any way whatever.EXAMPLESExample-1: Synthesis N-(4-chloro-2-methylphenyl)-2-(hydroxyimino)acetamideMethod- 1:Step-1: Preparation of 2,2-diacetoxyacetic acid (2)Preparation of 2,2-diacetoxyacetic acid (2)

[0046] Method 1: To a solution of 2,2-dihydroxyacetic acid (monohydrate(95%)) (18.4 g, 190 mmol) in acetic acid (30 mL, 1.6 Vol.), acetic anhydride (126 mL, 1329 mmol, 7 eq.) was added at room temperature and heated to reflux for 2 hours at 120 °C. After completion of the reaction, the volatiles were removed via an azeotropic distillation with toluene (20 mL) and concentrated under reduced pressure to obtain 2,2-diacetoxyacetic acid (2) as a light brown oil which was used for the next step without purification.

[0047] Method 2: To a solution of 2,2-dihydroxyacetic acid (50% glyoxalic acid was concentrated to an extent of 80-85%) (25 g, 272 mmol) in acetic acid (40 mL, 1.6 Vol.), acetic anhydride (77 mL, 815 mmol, 3 eq.) was added at room temperature and heated to reflux for 2 hours at 120 °C. After completion of the reaction, the volatiles were removed via an azeotropic distillation with toluene (25 mL) and concentrated under reduced pressure to obtain 2,2-diacetoxyacetic acid (2) as a light brown oil which was used for the next step without purification. 'H-NMR (400 MHz, DMSO-D6) 8 6.667 (s, 1H) ppm.Step-2: Preparation of 2-chloro-2-oxoethane- 1,1 -diyl diacetate (3)

[0048] To a solution of 2,2-diacetoxyacetic acid (110.936 g, 630 mmol) in toluene (348 mL), thionyl chloride (115 mL, 1575 mmol, 2.5 eq.) was added and heated to reflux for 1 hour. After completion of the reaction, the volatiles wereremoved via an azeotropic distillation with toluene (2x230 mL) and concentrated under reduced pressure to obtain 2-chloro-2-oxoethane- 1,1 -diyl diacetate (3) (136.88 g, 703.511 mmol) as a brown sticky oil and was used for the next step without further purification.Step-3: Synthesis of 2-((4-chloro-2-methylphenyl)amino)-2-oxoethane-l,l-diyl diacetate (XVII)

[0049] To an ice-cooled stirred solution of 4-chloro-2-methylaniline (1.0 eq.) in 1,2-dichloroethane (DCE) (6 vol.), sodium bicarbonate (3.75 eq.) was added under nitrogen atmosphere. To this reaction mass, a solution of 2-chloro-2- oxoethane- 1,1 -diyl diacetate (1.2 eq.) in DCE (2 vol.) was added dropwise maintaining the temperature below 5 °C. The resulting reaction mixture was stirred at 25 °C for 1.5 hours. After completion of the reaction, the reaction mixture was filtered and the filtrate was concentrated under reduced pressure to obtain 2-((4- chloro-2-methylphenyl)amino)-2-oxoethane- 1,1 -diyl diacetate (XVII) as a sticky brown oil.Step-4: Synthesis of N-(4-chloro-2-methylphenyl)-2-(hydroxyimino)acetamide(IVa)

[0050] To a stirred solution of the 2-((4-chloro-2-methylphenyl)amino)-2- oxoethane- 1,1 -diyl diacetate in a solvent mixture of ethanol: water (2:1), hydroxylamine hydrochloride (1.5 eq.) was added at room temperature. The reaction mass was gradually heated up to 95 °C and maintained at the same temperature for 2 hours. After completion of the reaction, the reaction mixture wascooled to room temperature and the majority of the solvent was removed under reduced pressure. Water was added until a precipitate appeared, which was filtered, washed with water and dried under reduced pressure to obtain the N-(4-chloro-2- methylphenyl)-2-(hydroxyimino)acetamide (IVa) as a beige powder (78%).'H-NMR (400 MHz, DMSO-D6) 8 12.22 (s, 1H), 9.53 (s, 1H), 7.67 (s, 1H), 7.50 (d, J = 8.6 Hz, 1H), 7.32 (d, J = 2.1 Hz, 1H), 7.24 (dd, J = 8.6, 2.4 Hz, 1H), 2.19 (s, 3H) ppm; MS: m / z = 211.95 [M+H]+

[0051] The oximes (IVb-IVd) were obtained in an analogous manner.2-(hydroxyimino)-W(o-tolyl)acetamide (IVb)-Yield: 78%;'H-NMR (400 MHz, DMSO-D6) 5 11.06 (s, 1H), 7.41 (d, J = 7.6 Hz, 1H), 7.32 (d, J = 7.3 Hz, 1H), 6.99-6.95 (m, 1H), 2.17 (t, J = 14.7 Hz, 3H) ppm; MS: 177.05 m / z [M-H]-W(4-bromo-2-methylphenyl)-2-(hydroxyimino)acetamide (IVc)-Yield:90%'H-NMR (400 MHz, DMSO-D6) 812.22 (s, 1H), 9.52 (s, 1H), 7.67 (s, 1H), 7.46- 7.44 (m, 2H), 7.36 (dd, J = 8.6, 2.1 Hz, 1H), 2.19 (s, 3H) ppm; MS: m / z = 255.70 [M-H]-W(2-bromo-4-chlorophenyl)-2-(hydroxyimino)acetamide (IVd)-Yield:79%'H-NMR (400 MHz, DMSO-D6) 8 12.46 (s, 1H), 9.50 (s, 1H), 7.89 (d, J = 8.9 Hz, 1H), 7.83 (d, J = 2.4 Hz, 1H), 7.65 (s, 1H), 7.49 (dd, J = 8.9, 2.4 Hz, 1H); MS: m / z = 276.35 [M-H]-Example 2: Synthesis of 2-(hydroxyimino)- V-(u-tolyl)acetamide (IVb)Method-II

[0052] Into a solution of o-toluidine (III, 75 g, 700 mmol) in water (170 mL), hydrochloric acid (73 g, 700 mmol, 35% w / w) was slowly added, followed by the addition of a solution of anhydrous sodium sulphate (636 g, 4478 mmol) in water (800 mL). The resulting reaction mixture was heated to 55 °C. Then an aqueous solution of hydroxylamine hydrochloride (73 g, 1050 mmol) in water (280 mL) was slowly added, followed by the addition of chloral hydrate (125 g, 757 mmol) in water (270 mL). The reaction mixture was maintained at 55 °C for 12 h. After completion of the reaction, the reaction mixture was cooled to 20 °C and stirred for 1 h. The solid product was filtered and washed two times with water (100 mL) to obtain 2-(hydroxyimino)-A-(o-tolyl)acetamide (IVb, 95 g, 531 mmol, Yield: 76%).

[0053] XH-NMR (400 MHz, DMSO-76) 6 12.16 (s, 1H), 9.47 (bs, 1H), 7.66 (s, 1H), 7.45-7.47 (d, J = 7.8 Hz, 1H), 7.19-7.24 (dd, J = 7.4 Hz & 0.6 Hz, 1H), 7.14-7.18 (td, 7 = 7.6 Hz & 1.6 Hz, 1H), 7.08-7.13 (td, 7 = 7.4 Hz & 1.3 Hz, 1H), 2.22 (s, 3H)MS: m / z = 179.05 [M+H],Example-3: Synthesis of \-(4-chh)ro-2-methylphenyl)-2-(hydroxyimino)acetamide (IVa) Method-Ill

[0054] To a suspension of 2-chloro-A-(4-chloro-2-methylphenyl)acetamide (II, 24 g, 110 mmol) in 2-propanol (212 mL), hydroxyl amine hydrochloride (22.9 g, 330 mmol) was added, followed by slow addition of N,N diisopropylethylamine (DIPEA) (43.7g, 330 mmol) at 25-30 °C. The resulting suspension was stirred for 18 h at 78 °C. After completion of the reaction, the solvent (2-propanol) was evaporated, and to the obtained residue water (100 mL) was added. The resulting precipitated product was filtered and dried under reduced pressure to obtain A-(4- chloro-2-methylphenyl)-2-(hydroxyimino)acetamide (IVa, 17.34 g, 81.4 mmol).

[0055] 1H-NMR (DMSO-6, 400 MHz): 12.2 (br, 1H), 9.56 (s, 1H), 7.68 (s,1H), 7.50 (d, J = 8.8 Hz, 1H), 7.36 (dd, JI = 8.4, J2 = 2.4 Hz, 1H), 7.31 (d, J = 2.4 Hz, 1H), 2.19 (s, 3H) ; MS: m / z = 211 [M-H]Example-3a: In-situ- synthesis of 2-chloro-N-(4-chloro-2- methylphenyl)acetamide (II) from o-toluidine (III)

[0056] To a solution of o-toluidine (III, 590 g, 4573 mmol) in dichloro ethane (DCE) (2400 mL), triethyl amine (532 mL, 5259 mmol) was added at 25 °C. The mixture was cooled to 0°C and a solution of 2-chloroacetyl chloride (614 mL, 5259 mmol) in DCE (400 mL) was slowly added at 0-10 °C. The reaction mixture was stirred for 4 h at 25-30 °C. After complete consumption of o-toluidine, the reaction mixture was cooled to 0 °C and a solution of sulfuryl chloride (715 g, 5030 mmol) in DCE (400 mL) was added during 4 h and stirred at 25 °C for 12 h. After completion of the reaction, excess solvent was distilled at reduced pressure and water (2000 mL) was added to it. The resulting precipitated product was filtered, washed with water (500 mL X 2) and dried under reduced pressure to obtain 2- chloro-N-(4-chloro-2-methylphenyl)acetamide (II, 842 g, 3864 mmol).Example-3b: Synthesis of 2-chloro-N-(4-chlorophenyl)acetamide.

[0057] To a stirred solution of 4-chloroaniline (III, 20 g, 157 mmol) in ethylene dichloride (120 g), triethyl amine (31.7 g, 314 mmol) was added at room temperature, followed by the addition of a solution of 2-chloroacetyl chloride (35.4 g, 314 mmol) in ethylene dichloride (20 g) at 0-5°C during a period of 60 min. The reaction mixture was stirred at 20-25 °C for 6 h. After completion of the reaction, the solvent was evaporated, and water (80 g) was added. The precipitated product was filtered and dried under reduced pressure to obtain 2-chloro-N-(4- chlorophenyl) acetamide (II, 25.6 g, 125 mmol).

[0058] ’ H-NMR (400 MHz, DMSO-6) 6 10.42 (s, 1H), 7.61 (tt, J = 9.2 Hz, 2H), 7.35 (tt, J = 8.8 Hz, 2H), 4.24 (s, 2H). MS: m / z = 202 [M-H]Example-4: Synthesis of V-(4-bromo-2-methvlphenvl)-2-(hydroxyimino)acetamide (IVc)Method III:

[0059] To a suspension of A-(4-bromo-2-methylphenyl)-2-chloroacetamide (II, 3g, 11.4 mmol) in 2-propanol (25 mL), hydroxyl amine hydrochloride (2.4 g, 34.2 mmol) was added, followed by slow addition of N,N diisopropylethylamine (DIPEA) (4.4g, 34.2 mmol) at 25-30 °C. The resulting suspension was stirred for 18 h at 78 °C. After completion of the reaction, the solvent (2-propanol) was distilled off, and water (12 mL) was added to the residue. The resulting precipitated product was filtered and dried under reduced pressure to obtain A-(4-bromo-2- methylphenyl)-2-(hydroxyimino)acetamide (IVc, 2.3 g, 9.12 mmol).

[0060] XH-NMR (DMSO-6, 400 MHz): 12.22 (s, 1H), 9.52 (s, 1H), 7.67 (s, 1H), 7.46-7.45 (m, 1H), 7.44 (s, 1H), 7.35 (dd, JI = 8.4, J2 = 2.4 Hz, 1H), 2.19 (s, 3H); MS: m / z = 256 [M-H]Example-5: Synthesis of V-(2-bromo-4-chlorophenyl)-2-(hydroxyimino)acetamide (IVd)

[0061] To a suspension of A-(2-bromo-4-chlorophenyl)-2-chloroacetamide (II, 3 g, 10.6 mmol) in 2-propanol (25 mL), hydroxyl amine hydrochloride (2.2 g, 31.8 mmol) was added, followed by slow addition of A,A-diisopropylethylamine (DIPEA) (4.1 g, 31.8 mmol) at 25-30 °C. The resulting suspension was stirred for 18 h at 78 °C. After completion of the reaction, the solvent (2-propanol) was distilled off and water (12 mL) was added to the residue. The resulting precipitatedproduct was filtered and dried under reduced pressure to obtain A-(2-bromo-4- chlorophenyl)-2-(hydroxyimino)acetamide (IVd, 2.1g, 7.4 mmol).

[0062] ’ H-NMR (DMSO-76, 400 MHz): 12.45 (br, 1H), 9.48 (s, 1H), 7.90 (d, 7 = 8.4, 1H), 7.81 (s, 1H), 7.65 (s, 1H), 7.42 (d, 7 = 4, 1H); MS: m / z = 276.8 [M- H]Example-6 to 9: Isatin formation

[0063] To an ice-cold stirred solution of the oxime (IVa-e) (1 g), in a solvent, cone, sulfuric acid (98%, 7 eq.) was added dropwise maintaining the temperature below 10 °C. After complete addition, the temperature of the reaction mass was gradually raised to 50 °C and continued to stir at the same temperature for 12 hours. After completion of the reaction, the reaction mass was cooled to 0- 5 °C and chilled water (10 Vol.) was added slowly under stirring to obtain an orange precipitate. The temperature of the reaction mass was again raised to 50 °C and kept under stirring for 1 hour. After Ihour, the solid was collected via filtration followed by drying under reduced pressure to obtain the oximes (formula VI) (7a-e) (65-96% yield) as an orange fine powder.Table -2: Synthesis of compound of formula (VI) from compound of formula (IV)Example-10: Synthesis of 5-chloro-7-methylindoline-2, 3-dione (VIB)

[0064] Method- 1: To a stirred solution of 7 -methylindoline-2, 3 -dione (VIC,67.0 g, 0.42 mol) in A-methylpyrrolidone (150 g), chlorine gas (halogenation reagent, 81.0 g, 1.15 mol) was purged at 45 °C. After 30 min, 2-propanol (225 g) was added at 50-55 °C to the resulting suspension over a period of 5-10 min. The reaction mixture was cooled to 25-30 °C. The solid product obtained was isolated by filtration, washed with 2-propanol (75 g), water (75 g) and dried under reduced pressure to obtain 5-chloro-7-methylindoline-2, 3-dione (VIB, 65 g, 0.33 mol).

[0065] Method-2: To a stirred solution of 7 -methylindoline-2, 3 -dione (VIC,10 g) in acetic acid (84 g), chlorine gas (halogenation reagent; 6.2 g) was purged at 45+5 °C. The reaction mixture was cooled to 25-30 °C, after completion of reaction,nitrogen gas was purged to remove dissolved chlorine. The solid product obtained was filtered, and dried under reduced pressure to obtain 5-chloro-7-methyhndohne- 2, 3-dione (10 g)Example-11: Synthesis of 2-amino-N-(methyl)-5-chloro-3-methylbenzamide(IB)

[0066] 5-Chloro-7-methylindoline-2, 3-dione (VIB, 10.0 g, 0.0481 moles) and caustic lye (2.35 g, 48.9% aq. solution., 0.0557 moles) was charged to water (20 g) at a temperature of 25+5 °C and the reaction mixture was heated to 40±5°C under stirring for 2-3 h. After completion of the reaction, the reaction mixture was charged with methylamine (22.39 g, 40% aq. solution, 0.288) at a temperature of 40+5 °C and continued to stir further for 5-6 h at the same temperature. After completion of the reaction, the reaction mixture was cooled to 25+5 °C, and charged with toluene (5 g) followed by dropwise addition of hydrogen peroxide (H2O2) solution (22.61 g; 48% aq. solution, 0.312 moles) maintaining a temperature of 25+5 °C, and continued to stir further for 2-3 h at the same temperature. After completion of the reaction, the reaction mass was filtered. The wet cake obtained was washed with water (10 g) and dried to afford pure 2-amino- 5-chloro-A, 3 -dimethylbenzamide (IB, 7.8 g) as an off-white solid.

[0067] 'H-NMR: (400 MHz, DMSO- e) 6 8.307 (br d, J= 4, 1H), 7.384 (d, J= 2.4, 1H), 7.116 (d, J= 2, 1H), 6.339 (s, 2H), 2.711 (d, J= 4.4, 3H), 2.09 (s, 3H)Example-12: Synthesis of 2-amino-5-broino- \ -3-diniethylbenzamide (formula IB):Molecular Weight: 243.10Molecular Weight: 164.21

[0068] To a suspension of 2-amino-A,3-dimethylbenzamide (I, 10 g) in 47% aq HBr (147 gm, 2.14 mol), hydrogen peroxide (5 gm,) was added at 15-20 °C over a period of 30-60 min. The reaction mass was stirred for 2-3h. After completion of the reaction, the reaction mass was filtered and dried to obtain 2- amino-5-bromo-N, 3 -dimethylbenzamide salt. The obtained 2-amino-5-bromo-N,3- dimethylbenzamide salt was neutralized with aq sodium hydroxide solution to obtain 2-amino-5-bromo-N,3-dimethylbenzamide (IB, 13.3 g)Example-13: Synthesis of 2-amino-5-cyano-N,3-dimethylbenzamide

[0069] A mixture of A-methyl-2-pyrrolidone (NMP, 25 mL), 2-amino-5- bromo-A,3-di methyl benzamide (IC, 50 g, 1 equivalent), copper(I) iodide (3.55 g, 0.1 eq), potassium ferrocyanide trihydrate (K4Fe(CN)6.3H2O; source of CN“ ion), 39.4 g, 0.5 equivalent), and sym-dimethylethylenediamine technical (DMEDA), 4.93 g, 0.3 equivalent) was stirred for 20 h at 120 °C. On completion of the reaction, the reaction mixture was cooled to 45 °C and filtered through a Buckner funnel under suction. The obtained solid was washed with n-butanol and dried under vacuum to afford 34 g of 2-amino-5-cyano-A,3-dimethylbenzamide (ID).

[0070] The compound of formula (IA) or formula (ID) was converted to the compound of formula (Aa) by using any of the method disclosed in WO2012103436, W02008010897 and W02006062978.

Claims

WE CLAIM:

1. A method for the synthesis of a compound of formula (I),formula (I) wherein,R is selected from hydrogen, halogen, cyano, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and n represents an integer selected from 0-4; comprising the steps of:A. preparing an isatin of formula (VI),formula (VI) by reacting a mixture comprising of, i. an oxime derivative of formula (IV)Re is represented by H or C1-C4 alkyl; and R is as described above;ii. cyclizing reagent, wherein the cyclizing reagent is a mixture of two or more acids, iii. optionally in the presence of a solvent; andB. preparing a compound of formula (I) by reacting a mixture comprising of, i. an isatin of formula (VI) obtained in step A; ii. a base; iii. optionally in the presence of a solvent; iv. an amine of formula (IX) or salt thereof;H2N - R4formula (IX) v. an oxidizing agent; wherein said method optionally comprising the step of: halogenating the isatin of formula (VI), wherein at least one R is hydrogen, with a suitable halogenation reagent, optionally in the presence of a suitable solvent to obtain halogenated isatins of formula (VI).

2. The method as claimed in claim 1, wherein said method for the preparation of a compound of formula (I) comprises the steps of:A. Preparing an isatin of formula (VI), by cyclizing the compound of formula (IV) with a cyclizing reagent to obtain isatin of formula (VI);wherein the cyclizing reagent is a mixture of two or more acids;B. preparing the amide of formula (I) by,(B-a). forming a mixture comprising of i. isatin of formula (VI) or salt thereof,formula (VI) ii. a base and optionally in the presence of solvent; to obtain a compound of formula (XI),formula (XI) wherein M+represent metal ion; wherein the compound of formula (XI) or salt thereof, was optionally isolated;(B-b) introducing an amine compound of formula (IX) or salt thereof into the mixture;H2N - R4formula (IX)R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and reacting the mixture, to obtain a compound of formula (XII) or salt thereof,formula (XII) wherein the compound of formula (XII) or salt thereof, was optionally isolated;(B-c) introducing an oxidizing agent to the mixture; and reacting the mixture.

3. The method as claimed in claim 1, wherein the compound of formula I isformula (IA), wherein R is represented by R1, R2or R3,R1, R2, R3are independently represented by hydrogen, halogen, Ci-Ce alkyl, Ci-C6haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl.

4. The method as claimed in claim 1, wherein the compound of formula I is,formula (IB) wherein R is represented by R1, R2or X, X is Cl, Br or I; andR1and R2are independently hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl.

5. The method as claimed in claim 1 or claim 4, wherein the method for the preparation of a compound of formula (IB) from a substituted oxime derivative of formula (IVB), comprises the steps of:formula (IB) wherein,R is represented by R1, R2or X, R1and R2are independently represented by hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or Cs-Cs cycloalkyl;R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and X = Cl, Br, or I,A. preparing an isatin of formula (VIB) by cyclizing the compound of formula (IVB) with a cyclizing reagent to obtain an isatin of formula (VIB);and wherein the cyclizing reagent is a mixture of two or more acids;B. preparing the amide of formula IB by,(B-a). forming a mixture comprising of i. isatin of formula (VIB) or salt thereof,formula (VIB) wherein R1and R2are represented by hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; and X is Cl, Br, or I, ii. a base and optionally in the presence of solvent; to obtain a compound of formula (XIB),formula (XIB) wherein R1and R2are independently represented by hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; M+represent metal ion, X is represented by Cl, Br, or I; and wherein the compound of formula (XIB) or salt thereof, was optionally isolated;(B-b) introducing an amine compound of formula (IX) or salt thereof,H2N - R4formula (IX) into the mixture; reacting the mixture, to obtain a compound of formula (XIIB) or salt thereof,formula (XIIB) wherein,R1and R2are independently represented by hydrogen, halogen, Ci- C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3- Cs cycloalkyl; X is represented by Cl, Br, OR I; R4is selected from hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and wherein the compound of formula (XIIB) or salt thereof, was optionally isolated;(B-c) introducing an oxidizing agent to the mixture; and reacting the mixture.

6. The method as claimed in claim 1 or 4, wherein the preparation of a compound of formula (IB) comprises the steps of:formula (IB) wherein R represents R1, R2or X,R1and R2are represented independently by hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl; X is represented by Cl, Br, or I;A. preparing isatin of formula (VIB) by, i. cyclizing the compound of formula (IVC) with a cyclizing reagent to obtain isatin of formula (VIC);wherein R1and R2are represented by hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3- Cs cycloalkyl; Re is represented by H or Ci to C4 alkyl; and wherein the cyclizing reagent is a mixture of two or more acids; and ii. halogenating the isatin of formula (VIC) to obtain isatin ofwherein X is Cl, Br, or I; andB. preparing the amide of formula I by;(B-a). forming a mixture comprising of i. isatin of formula (VIB) or salt thereof, ii. a base and optionally in the presence of a solvent; to obtain a compound of formula (XIB),formula (XIB)wherein the compound of formula (XIB) or salt thereof, was optionally isolated;(B-b) introducing an amine compound of formula (IX) or salt thereof,H2N - R4formula (IX) into the mixture, and reacting the mixture, to obtain a compound of formula (XIIB) or salt thereof,wherein the compound of formula (XIIB) or salt thereof, was optionally isolated;(B-c) introducing an oxidizing agent to the mixture; and reacting the mixture.

7. The method as claimed in claim 1 or 4, wherein the preparation of a compound of formula (IB) from substituted oxime derivatives of formula (IVD),formula (IB) wherein R represents R1, R2or X,R1and R2are independently represented by hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl;R4is represented by hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 haloalkyl, C2-C12 haloalkenyl, C2-C12 haloalkynyl, C1-C12 alkoxy, C1-C12 haloalkoxy, C3-C8 cycloalkyl, or C3-C8 cycloalkyl-Ci-Cio alkyl; and X is represented by Cl, Br, or I; comprising the steps of:A. preparing isatin of formula (VID) by, cyclizing the compound of formula (IVD) with a cyclizing reagent to obtain isatin of formula (VID);wherein R represents R1, R2or H, R1and R2are independently represented by hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; Re is represented by H or Ci to C4 alkyl; and wherein the cyclizing reagent is a mixture of two or more acids; and B. preparing the amide of formula (XIID) by;(B-a). forming a mixture comprising of i. isatin of formula (VID) or salt thereof,formula (VID) wherein R1and R2are independently represented by hydrogen, halogen (X), C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, Ci- C12 haloalkoxy, or C3-C8 cycloalkyl; and X is Cl, Br, or I; ii. a base and optionally in the presence of solvent;to obtain a compound of formula (XID),formula (XID) wherein R1and R2are independently represented by hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; X is Cl, Br, or I; and wherein the compound of formula (XID) or salt thereof, was optionally isolated;(B-b) introducing an amine compound of formula (IX) or salt thereof,H2N - R4formula (IX) into the mixture, reacting the mixture, to obtain a compound of formula (XIID) or salt thereof,wherein,R1and R2are independently represented by hydrogen, halogen, Ci- C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3- Cs cycloalkyl; wherein the compound of formula (XIID) or salt thereof, was optionally isolated;(B-c). introducing an oxidizing agent and HX into the mixture; and reacting the mixture; wherein X = Cl, Br, or I;C. preparing a compound of formula (IB) from compound of formula (IC) obtained from step-B, by halogenating the compound of formula (IC) using a suitable halogenation reagents to obtain compound of formula (IB).

8. A method for preparing an isatin of formula (VI),formula (VI) wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl; and n represents an integer selected from 0-4; by reacting a mixture of, i. oxime derivatives of formula (IV)wherein R is selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl, n represents an integer selected from 0-4; and Re is selected from H or Ci to C4 alkyl; and ii. cyclizing reagent, wherein the cyclizing reagent is a mixture of two or more acids; iii. optionally in the presence of a solvent; and wherein said method optionally comprising the step of: halogenating the isatin of formula (VI), wherein at least one R is hydrogen, with a suitable halogenation reagent, optionally in the presence of a suitable solvent to obtain halogenated isatins of formula (VI).

9. The method as claimed in claim 8, wherein the compound of formula (VI)formula (VIA) wherein R is represented by R1, R2or R3, R1, R2and R3are independently selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C1-C12 haloalkoxy, or C3-C8 cycloalkyl.

10. The method as claimed in claim 8, wherein the compound of formula (VI)formula (VIB) wherein R is represented by R1, R2or X, R1and R2are independently selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, Ci- C12 haloalkoxy, or C3-C8 cycloalkyl, and X is represented by Cl, Br, or I.

11. The method as claimed in claim 8, wherein the compound of formula (VI) is:formula (VIC) wherein R is represented by R1, R2or H, R1and R2are independently selected from hydrogen, halogen, C1-C12 alkyl, C1-C12 haloalkyl, C1-C12 alkoxy, Ci- C12 haloalkoxy, or C3-C8 cycloalkyl.

12. The method as claimed in any of the above claims 1 to 11, wherein the reaction is carried out in a single step without purifying or isolating the intermediates.

13. The method as claimed in claim 4, further comprising the step of preparing compounds of formula (ID) from substituted amides of formula (IB),formula (ID) wherein, R is represented by R1, R2or CN, and R1, R2and R4are same as defined above; comprising the step of: reacting a compound of formula (IB) with a source of CN’ ions and in the presence of a suitable ligand.

14. The method according to claim 1, wherein said method further comprises the step of preparation of a compound of formula (Aa) or of salts thereof;Formula (Aa) wherein,R represents R1, R2or R3, R1, R2, R3are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from the group consisting of hydrogen, Ci-Ce alkyl, C3-C6 cycloalkyl, C3-C6 cycloalkyl-Ci-C4 alkyl;R5is selected from the group comprising of halogen, C1-C4 alkyl, C1-C4 haloalkyl, CHF2, CF3, C1-C4 alkoxy, OCHF2, OCH2CF3,heterocyclyl; wherein -A- is selected from the group comprising of a direct bond, CHR6, -O- or -S-; and said heterocyclyl may optionally be substituted with one or more group selected from hydrogen, halogen, cyano, C1-C4 alkyl or C1-C4 haloalkyl;R6is selected from the group comprising of hydrogen, halogen, cyano, Ci- C4 alkyl or C1-C4 haloalkyl; X represents Cl, Br or I; comprising the step of reacting a substituted anthranilic amide of formula (I), wherein the anthranilamide of formula (I) is (IA),formula (IA) wherein,R1, R2, R3are independently selected from hydrogen, halogen, Ci-Ce alkyl, Ci-Ce haloalkyl, Ci-Ce alkoxy, Ci-Ce haloalkoxy, or C3-C8 cycloalkyl;R4is selected from the group consisting of hydrogen, Ci-Ce alkyl, C3-C6 cycloalkyl, C3-C6 cycloalkyl-Ci-C4 alkyl; with a pyrazole compound of formula (B),wherein W is OH, Cl, O-C1-C4 alkyl, O-C(O)Ci-C4 alkyl or imidazolyl;R5is selected from the group comprising of halogen, C1-C4 alkyl, C1-C4 haloalkyl, CHF2, CF3, C1-C4 alkoxy, OCHF2, OCH2CF3,heterocyclyl; wherein -A- is selected from the group comprising of a direct bond, CHR6,-O- or -S-; and said heterocyclyl may optionally be substituted with one or more group selected from hydrogen, halogen, cyano, C1-C4 alkyl or C1-C4 haloalkyl;R6is selected from the group comprising of hydrogen, halogen, cyano, Ci- C4 alkyl or C1-C4 haloalkyl; X represents Cl, Br or I; in the presence of a coupling reagent, a suitable solvent, and optionally in the presence of a base, according to the following reaction scheme as depicted below.

15. The method as claimed in claim 1, wherein the compound (IV) is prepared by: reacting the compound of Formula (III) and chloral hydrate and hydroxylamine in the presence of hydrochloric acid, sulfuric acid, acetic acid, trifluoroacetic acid, nitric acid or sodium sulphate and one or moresolvents at a temperature in the range from 15 °C to 150 °C, wherein Re = H;(in) (IVF)(OR) reacting a compound of formula (II) with a hydroxyl amine compound in the presence of a suitable base and a suitable solvent,Re = H or Ci-Ce alkyl,(OR) reacting a compound of formula (II) with hydroxyl amine in the presence of a suitable base and a suitable solvent, wherein Re = H;(i) reacting glyoxalic acid with acetic anhydride at a temperature of 80- 130 °C, optionally isolating the intermediate (2) which was further reacted with thionyl chloride to obtain a compound of formula (3); and(ii) reacting the compound of formula (III) with the compound of formula (3), optionally isolating the intermediate compound offormula (XVII), to afford a compound of formula (IVF), optionally in the presence of a suitable base and a suitable solvent,wherein the compound of formula (IVF) is a compound of formula (IV)wherein Re is H.

16. The method as claimed in claim 1, 4, 5, 6 or 7, wherein the halogenation is carried out in the presence of a suitable halogenation reagent which is selected from HX, NaX, KX, CuX2, MgX2, CsX, ZnX2, SOC12, SO2C12, COC12, X2, C(=O)(OC13)2, t-BuOCl, NaOCl, HX + H2O2, N- halosuccinamides, methane sulfonyl chloride, POX3, PX3, PX5 or metal halides; wherein X is Cl, Br, I or F.

17. The method as claimed in claim 16, wherein the halogenation is carried out in the presence of a suitable halogenation reagent which is selected from X2; SOC12, SO2C12, or HX+H2O2wherein X represents Cl or Br.

18. The method as claimed in claim 1, claim 2, claim 5, or claim 8, wherein the cyclizing reagent is a mixture of two or more acids selected from the group consisting of hydrochloric acid, hydrobromic acid, sulfuric acid, formic acid, acetic acid, trifluoroacetic acid, propionic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, acidic ion-exchange resin, AIX3, BX3, FeX3, ZnX2, GaX3, InX3, TiX4, BiX3, SbX3, SnX2, SnX4, SiX4, POX3, and hypovalent Lewis acids, wherein X = F, Cl, Br and I.

19. The method as claimed in claim 1, claim 2, claim 5, claim 8, or claim 18, wherein the cyclizing reagent is a mixture of two or more acids selected from the group consisting of sulfuric acid, formic acid, trifluoroacetic acid, methanesulfonic acid, and POX3, wherein X = Cl, or Br.

20. The method as claimed in claim 18 or claim 19, wherein the two acids are selected in a ratio in the range of 1:100 to 100:1, 1:50 to 50:1, 1:25 to 25:1, 1:20 to 20:1, 1:10 to 10:1 and 1:5 to 5:1.

21. The method as claimed in claim 1, claim 2, claim 5, or claim 8, wherein the cyclizing is carried out at temperatures in the range of 0 to 200 °C, 10 to 180 °C, 25 to 160 °C, 25 to 140 °C or 25 to 130 °C.

22. The method as claimed in claim 1 or claim 8, wherein the cyclizing is carried out in the presence of 1 to 20, 1 to 15, 1 to 10, 1 to 7, or 1 to 5 molar equivalents of the mixture of acids, with respect to the compounds of formula (IV).

23. The method as claimed in claim 13, wherein the source of CN“ ions in carrying out the cyanation reactions is selected from the group consisting of metal cyanide particularly, sodium cyanide (NaCN), potassium cyanide (KCN), copper(I)cyanide (CuCN), zinc(II) cyanide (Zn(CN)2), sodium ferrocyanide (Na4Fe(CN)e, Potassium hexacyanoferrate (III) (K3[Fe(CN)e]), and potassium hexacyanoferrate (II) (K4[Fe(CN)6]).

24. The method as claimed in claim 13, wherein the ligand is selected from the group consisting of 1,1 -dimethylethylenediamine (DEMDA), ethylenediamine, 1 -butyl- IH-imidazole, 2-picoline, 3-picoline, 2,6-lutidine, 2-hydroxypyridine, pyrrolidine and 1 -methyl pyrrolidine.

25. The method as claimed in claim 13, wherein the reaction is carried out in the presence of a catalyst selected from copper salts such as copper (I) iodide (Cui), copper (I) chloride, copper (I) bromide, copper acetate and potassium salts such as potassium iodide (KI).

26. The method as claimed in claim 1, wherein the oxidizing agent is selected from oxygen, chlorine, sodium hypochlorite, chromium trioxide, 3- chloroperoxybenzoic acid, hydrogen peroxide, tert-butyl hydroperoxide, peroxyacetic acid, potassium peroxymonosulfate, potassium permanganate, and combinations thereof.

27. The method as claimed in claim 1, wherein the base is selected from the group consisting of sodium carbonate (Na2COs), calcium carbonate (CaCCh), cesium carbonate (CS2CO3), lithium carbonate (Li2CO3), potassium carbonate (K2CO3), lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), cesium hydroxide (CsOH), calcium hydroxide (Ca(OH)2), sodium diphosphate (Na2HPO4), sodium phosphate(NasPC ), potassium diphosphate (K2HPO4), and potassium phosphate (K3PO4).

28. The method as claimed in claim 1, wherein the reaction is carried out in the presence of 1 to 5, 1 to 4, 1 to 3, 1 to 2, or 1 molar equivalents of a suitable amine of formula (IX) H2N-R4, with respect to the compound of formula VI.

29. The method as claimed in claim 1, wherein the reaction is carried out in the presence of 1 to 20, 1 to 15, 1 to 10, 1 to 7, 1 to 5, 1 to 2 or 1 molar equivalents of a suitable oxidizing agent, with respect to the compound of formula VI.

30. The method as claimed in claim 1, wherein the reaction in step B is carried out at temperatures in the range of -40 to 50, -20 to 50, -10 to 30, 0 to 30 or5 to 25 °C.

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