Title of the Invention: A PROCESS FOR PREPARING PHENYLAMIDINE COMPOUNDS AND INTERMEDIATES THEREOF FIELD OF THE INVENTION The present invention relates to a novel process for preparing phenylamidine compounds of formula (I) or of salts thereof. BACKGROUND OF THE INVENTION Phenylamidine compounds can be obtained by various routes as disclosed in the following reaction schemes. WO2018069841 discloses a reaction scheme (Scheme 1) for the synthesis of a compound of formula (1) which involves the reaction of a compound of formula (2) with trimethyl orthoformate and N-ethylmethylamine. Compounds of formula (2) are obtained by reaction of compounds of formula (3) with sodium hydroxide in an appropriate solvent system such as ethanol and water. Scheme 1: The aniline intermediate of formula (2) is showing color impurities after isolation and also gives lesser yields in further conversions. This issue has been addressed by the present invention wherein the compounds of formula (1) are synthesized in a single step from compounds of formula (3) avoiding the isolation of the aniline derivatives of formula (2). WO2018108998 discloses a reaction scheme (Scheme 2) for the preparation of compounds of formula (2a), exemplified by the reaction of the boronic ester derivative of formula (4) with 2-fluorobenzyl chloride using tetrakis(triphenylphosphine)palladium as a catalyst in the presence of caesium carbonate in 1-butanol and water as solvent system. The obtained compound of formula (2a) is then reacted with N-(dimethoxymethyl)-N-methylethanamine to obtain the compound of formula (1a). This reaction uses a boronic ester derivative and a palladium based catalyst which makes this process costly. The process disclosed in the present invention avoids the use of boronic ester derivatives as well as of palladium based catalyst. Scheme 2: The processes described in the prior art have shortcomings such as being expensive or laborious, or they lack from sufficient selectivity. Therefore, there is a need to find a simple, efficient, and industrial economical process for the preparation of phenylamidine compounds of formula (I), which has been addressed by the present invention. OBJECTIVE OF THE INVENTION An objective of the present invention is to provide a simple, environment-friendly, and cost-effective process for the preparation of phenylamidine compounds of formula (I) or of salts thereof, based on easily available starting materials. Other objectives and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure. SUMMARY OF THE INVENTION Accordingly, the present invention provides a solution to this objective by providing a novel process that allows the preparation of phenylamidine compounds of formula (I) or of salts thereof, overcoming at least one of the shortcomings of the processes described in the prior art. The said objective was achieved according to the present invention by providing a novel process for preparing a compound of formula (I) or of salts thereof. In one embodiment, the present invention provides a process for preparing a compound of formula (I), (I) wherein, R ¹ and R ² are independently selected from the group consisting of C ₁ -C ₆ -alkyl, C ₃ -C ₆ -cycloalkyl-C ₁ - C ₃ -alkyl, and C ₃ -C ₆ -cycloalkyl; R ³ and R ⁴ are independently selected from the group consisting of halogen, cyano, C ₁ -C ₆ -alkyl, C ₁ -C ₆ - haloalkyl, C ₁ -C ₆ -alkoxy, and C ₃ -C ₆ -cycloalkyl; R ⁵ and R ⁶ are independently selected from the group consisting of hydrogen, halogen, hydroxy, cyano, C ₁ -C ₃ -alkyl, and C ₁ -C ₃ -alkoxy; or R ⁵ and R ⁶ together with the carbon atom to which they are attached may form a “=O” or cyclopropyl ring; R ⁷ is selected from the group consisting of hydrogen, halogen, cyano, nitro, C ₁ -C ₆ -alkyl, C ₁ -C ₆ - haloalkyl, C ₁ -C ₆ -alkoxy, C ₁ -C ₆ -alkylthio, C ₁ -C ₆ -alkylsulfinyl, C ₁ -C ₆ -alkylsulfonyl, C ₃ -C ₆ -cycloalkyl, and C ₃ -C ₆ -cycloalkyl-C ₁ -C ₃ -alkyl; wherein R ⁷ optionally substituted with halogen, cyano, C ₁ -C ₄ -alkyl or C1-C4-alkoxy; m represents an integer selected from 0 to 4; and salts, N-oxides, metal complexes, or stereo-isomers thereof; comprising the step-A of: reacting a compound of formula (VII) or of salts thereof, wherein, R ⁸ is selected from the group consisting of C1-C6-alkyl, C1-C6-alkoxy, and C1-C6-haloalkyl; m, R ³ , R ⁴ , R ⁵ , R ⁶ , and R ⁷ are as defined above, with a compound of formula (VIII) or of salts thereof, wherein, R ¹ and R ² are as defined above, in the presence of a suitable acid and optionally in the presence of a solvent as shown in the scheme below: wherein, m, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ are as defined above. In another embodiment, the present invention provides a process for preparing an intermediate compound of formula (VII) or of salts thereof, wherein, m, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ are as defined above; comprising of at least one of the following schemes from (a) to (c): a) Scheme-a: reacting a compound of formula (IV) or of salts thereof with a compound of formula (XII) or of salts thereof, in the presence of a suitable metal complex/salt and in the presence of a suitable solvent to obtain a compound of formula (VII) or of salts thereof: wherein, X is halogen; m, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are as defined above; or; b) Scheme-b: in step-1, reacting a compound of formula (IV) or of salts thereof, with a compound of formula (XII) or of salts thereof in the presence of a suitable Lewis acid and optionally in the presence of a solvent to obtain a compound of formula (VI) or of salts thereof; which in a subsequent step (step-2) is converted into a compound of formula (VII) or of salts thereof using a suitable reducing reagent, a suitable acid and in the presence of a suitable solvent. wherein, X is halogen; m, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are as defined above, or; c) Scheme-c: in step-1, reacting a compound of formula (IVa) or of salts thereof with a compound of formula (XIIa) or of salts thereof in the presence of a suitable organometallic compound and in the presence of a suitable solvent to obtain a compound of formula (VIa) or of salts thereof; which in a subsequent step (step-2) is converted into a compound of formula (VII) or of salts thereof using a suitable reducing reagent, a suitable acid and in the presence of a suitable solvent. wherein, X is halogen; m, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are as defined above. DETAILED DESCRIPTION OF THE INVENTION: GENERAL DEFINITIONS The definitions provided herein for the terminologies used in the present disclosure are for illustrative purposes only and in no manner limit the scope of the present invention disclosed in the present disclosure. 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. 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. 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 characteristic(s) of the claimed invention. The term “consisting essentially of” occupies a middle ground between “comprising” and “consisting of”. 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). 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 meant to be singular. As used herein, the term” condensing” or “contacting” or “subjecting” or “reacting” or “treating” refers to a process of combining reactant(s) in a suitable medium or in a solvent, wherein the reactant gets converted into the product under reaction condition described. As used herein, the term” sufficient formation” refers to wherein, the conversion of reactant(s) into the product is 50 % or more under the reaction conditions described. 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 C1-C6 alkyl, C1-C6 haloalkyl, and phenyl optionally substituted with 1-3 substituents selected from C1-C3 alkyl, halogen, and nitro. The meaning of various terms used in the description shall now be illustrated. 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 C1 to C6 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 also applies to composite substituents in which other radicals, for example alkenyl, alkynyl, hydroxyl, halogen, carbonyl, carbonyloxy and the like, are at the end. The term “cycloalkyl” means alkyl closed to form a ring. Non-limiting examples include cyclopropyl, cuclobutyl, cyclopentyl, and cyclohexyl. This definition also applies to cycloalkyl as a part of a composite substituent, for example cycloalkylalkyl etc., unless specifically defined elsewhere. The term “halogen”, either alone or in compound words such as “halomethyl”, or “haloalkyl”, includes fluorine, chlorine, bromine or iodine. Further, when used in compound words such as “halomethyl”, “haloalkyl”, said alkyl or methyl 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, 1,1-dichloro-2,2,2-trifluoroethyl, and 1,1,1- trifluoroprop-2-yl. The term "alkoxy" used either alone or in compound words included C1 to C6 alkoxy. Non limiting examplesof 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. The term "hydroxy" means –OH. The term “alkylthio” includes branched or straight-chain alkylthio moieties such as methylthio, ethylthio, propylthio, 1-methylethylthio, butylthio, 1-methylpropylthio, 2-methylpropylthio, 1,1- dimethylethylthio, pentylthio, 1-methylbutylthio, 2-methylbutylthio, 3-methylbutylthio, 2,2- dimethylpropylthio, 1-ethylpropylthio, hexylthio, 1,1-dimethylpropylthio, 1,2-dimethylpropylthio, 1- methylpentylthio, 2-methylpentylthio, 3-methylpentylthio, 4-methylpentylthio, 1,1-dimethylbutylthio, 1,2-dimethylbutylthio, 1,3-dimethylbutylthio, 2,2-dimethylbutylthio, 2,3-dimethylbutylthio, 3,3- dimethylbutylthio, 1-ethylbutylthio, 2-ethylbutylthio, 1,1,2-trimethylpropylthio, 1,2,2- trimethylpropylthio, 1-ethyl-1-methylpropylthio and l-ethyl-2-methylpropylthio and the different isomers. Non-limiting examples of “alkylsulfinyl” include methylsulphinyl, ethylsulphinyl, propylsulphinyl, 1- methylethylsulphinyl, butylsulphinyl, 1-methylpropylsulphinyl, 2-methylpropylsulphinyl, 1,1- dimethylethylsulphinyl, pentylsulphinyl, 1-methylbutylsulphinyl, 2-methylbutylsulphinyl, 3- methylbutylsulphinyl, 2,2-dimethylpropylsulphinyl, 1-ethylpropylsulphinyl, hexylsulphinyl, 1,1- dimethylpropylsulphinyl, 1,2-dimethylpropylsulphinyl, 1-methylpentylsulphinyl, 2- methylpentylsulphinyl, 3-methylpentylsulphinyl, 4-methylpentylsulphinyl, 1,1- dimethylbutylsulphinyl, 1-ethyl-1-methylpropylsulphinyl and 1-ethyl-2-methylpropylsulphinyl and the different isomers. Non-limiting examples of “alkylsulfonyl” include methylsulphonyl, ethylsulphonyl, propylsulphonyl, 1-methylethylsulphonyl, butylsulphonyl, 1-methylpropylsulphonyl, 2-methylpropylsulphonyl, 1,1- dimethylethylsulphonyl, pentylsulphonyl, 1-methylbutylsulphonyl, 2-methylbutylsulphonyl, 3- methylbutylsulphonyl, 2,2-dimethylpropylsulphonyl, 1-ethylpropylsulphonyl, hexylsulphonyl, 1,1- dimethylpropylsulphonyl, 1,2-dimethylpropylsulphonyl, 1-methylpentylsulphonyl, 2- methylpentylsulphonyl, 3-methylpentylsulphonyl, 4-methylpentylsulphonyl, 1,1- dimethylbutylsulphonyl, 1-ethyl-1-methylpropylsulphonyl and l-ethyl-2-methylpropylsulphonyl and the different isomers. When a group contains a substituent which can be hydrogen, then, when this substituent is taken as hydrogen, it is recognized that said group is being un-substituted. The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of the ways in which the embodiments herein may be practiced and to further enable those skilled in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein. The description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications of such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modifications within the spirit and scope of the embodiments as described herein. The numerical values mentioned in the description and the description/claims though might form a critical part of the present invention of the present disclosure, any deviation from such numerical values shall still fall within the scope of the present disclosure if that deviation follows the same scientific principle as that of the present invention disclosed in the present disclosure. The compounds synthesized by the novel and inventive process of the present invention may, if appropriate, be present as mixtures of different possible isomeric forms, especially of stereo-isomers, for example, E and Z, threo and erythro, and also optical isomers, but if appropriate also of tautomers. Both the E and the Z isomers, and also the threo and erythro isomers, and the optical isomers, any desired mixtures of these isomers and the possible tautomeric forms are disclosed and claimed. The compound of formula (I) or (Z) and intermediates thereof is also read as including salts thereof. Exemplary salts include, but are not limited to: hydrochloride, hydrobromide, hydroiodide, trifluoroacetate, and trifluoromethane sulfonate. In view of the above, the present invention provides a process for preparing a compound of formula (I), (I) wherein, R ¹ and R ² are independently selected from the group consisting of C1-C6-alkyl, C3-C6-cycloalkyl-C1- C3-alkyl, and C3-C6-cycloalkyl; R ³ and R ⁴ are independently selected from the group consisting of halogen, cyano, C1-C6-alkyl, C1-C6- haloalkyl, C1-C6-alkoxy, and C3-C6-cycloalkyl; R ⁵ and R ⁶ are independently selected from the group consisting of hydrogen, halogen, hydroxy, cyano, C1-C3-alkyl, and C1-C3-alkoxy; or R ⁵ and R ⁶ together with the carbon atom to which they are attached may form a =O or cyclopropyl ring; R ⁷ is selected from the group consisting of hydrogen, halogen, cyano, nitro, C1-C6-alkyl, C1-C6- haloalkyl, C1-C6-alkoxy, C1-C6-alkylthio, C1-C6-alkylsulfinyl, C1-C6-alkylsulfonyl, C3-C6-cycloalkyl, and C ₃ -C ₆ -cycloalkyl-C ₁ -C ₃ -alkyl; wherein R ⁷ optionally substituted with halogen, cyano, C ₁ -C ₄ -alkyl or C ₁ -C ₄ -alkoxy; m represents an integer selected from 0 to 4; and salts, N-oxides, metal complexes or stereo-isomers thereof; comprising the step-A of: reacting a compound of formula (VII) or of salts thereof, wherein, R ⁸ is selected from the group consisting of C1-C6-alkyl, C1-C6-alkoxy, and C1-C6-haloalkyl; m, R ³ , R ⁴ , R ⁵ , R ⁶ , and R ⁷ are as defined above, with a compound of formula (VIII) or of salts thereof, wherein, R ¹ and R ² are as defined above, in the presence of a suitable acid and optionally in the presence of a solvent as shown in the below scheme: wherein, m, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ are as defined above. In another embodiment, the present invention provides a process for preparing an intermediate compound of formula (VII) or of salts thereof, wherein, m, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ are as defined above; comprising of at least one of the following schemes from (a) to (c), a) Scheme-a: reacting a compound of formula (IV) or of salts thereof with a compound of formula (XII) or of salts thereof, in the presence of a suitable metal complex/salt and in the presence of a suitable solvent to obtain a compound of formula (VII) or of salts thereof: wherein, X is halogen; m, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ are as defined above, or; b) Scheme-b: in step-1, reacting a compound of formula (IV) or of salts thereof with a compound of formula (XII) or of salts thereof in the presence of a suitable Lewis acid and optionally in the presence of a solvent to obtain a compound of formula (VI) or of salts thereof; which in a subsequent step (step-2) is converted into a compound of formula (VII) or of salts thereof using a suitable reducing reagent, a suitable acid and in the presence of a suitable solvent. wherein, X is halogen; m, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ are as defined above, or; c) Scheme-c: in step-1, reacting a compound of formula (IVa) or of salts thereof with a compound of formula (XIIa) or of salts thereof in the presence of a suitable organometallic compound and suitable solvent to obtain a compound of formula (VIa) or of salts thereof; which in a subsequent step (step-2) is converted into a compound of formula (VII) or into salts thereof using a suitable reducing reagent, a suitable acid and in the presence of a suitable solvent. wherein, X is halogen; m, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ are as defined above. In another embodiment, the present invention provides a process for preparing a compound of formula (I), (I) wherein, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and m are defined herein above, comprising the step-A of: reacting a compound of formula (VII) or of salts thereof, wherein, m, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ are as defined above, with a compound of formula (VIII) or of salts thereof, wherein, R ¹ and R ² are as defined above, in the presence of a suitable acid and optionally in the presence of a solvent, as shown in the below scheme: wherein, the compound of formula (VII) or of salts thereof is obtained by at least one of the following schemes (a) to (c); wherein, m, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ are as defined above, a) Scheme-a: reacting a compound of formula (IV) or of salts thereof with a compound of formula (XII) or of salts thereof, in the presence of a suitable metal complex/salt and in the presence of a suitable solvent to obtain a compound of formula (VII) or of salts thereof. wherein, X is halogen; m, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ are as defined above; or; b) Scheme-b: in step-1, reacting a compound of formula (IV) or of salts thereof with a compound of formula (XII) or of salts thereof in the presence of a suitable Lewis acid and optionally in the presence of a solvent to obtain a compound of formula (VI) or of salts thereof; which in a subsequent step (step-2) is converted into a compound of formula (VII) or of salts thereof using a suitable reducing reagent, a suitable acid and in the presence of a suitable solvent. wherein, X is halogen; m, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ are as defined above, or; c) Scheme-c: in step-1, reacting a compound of formula (IVa) or of salts thereof with a compound of formula (XIIa) or of salts thereof in the presence of a suitable organometallic compound and suitable solvent to obtain a compound of formula (VIa) or of salts thereof; which in a subsequent step (step-2) is converted into a compound of formula (VII) or of salts thereof using a suitable reducing reagent, a suitable acid and in the presence of a suitable solvent. wherein, X is halogen; m, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ are as defined above. In a preferred embodiment, the compound of formula (I) is (I) wherein, R ¹ is selected from the group consisting of methyl, ethyl, isopropyl, cyclopropyl, and cyclopropyl methyl; R ² is selected from the group consisting of methyl, ethyl, isopropyl, cyclopropyl, and cyclopropylmethyl; R ³ is selected from the group consisting of halogen, cyano, methyl, ethyl, isopropyl, halomethyl, and cyclopropyl; R ⁴ is selected from the group consisting of halogen, cyano, methyl, ethyl, isopropyl, halomethyl, methoxy, and cyclopropyl; R ⁵ and R ⁶ are independently selected from the group consisting of hydrogen, halogen, methyl, halomethyl, and methoxy; R ⁷ is selected from the group consisting of hydrogen, halogen, cyano, methyl, ethyl, isopropyl, halomethyl, methoxy, ethoxy, isopropoxy, and cyclopropyl; wherein R ⁷ is optionally substituted with halogen, cyano, methyl, ethyl, isopropyl, methoxy or ethoxy; m represents an integer selected from 0 to 4; and salts, N-oxides, metal complexes or stereo-isomers thereof. In one embodiment, the substituent R ⁸ is selected from the group consisting of C1-C6-alkyl, C1-C6- alkoxy, and C1-C6-haloalkyl. Preferably, the substituent R ⁸ is methyl, methoxy, ethoxy, propoxy, 1- methylethoxy, butoxy, 1-methylpropoxy or halomethyl. More preferably, the substituent R ⁸ is selected from methyl or methoxy. In one embodiment, the substituents R ⁵ and R ⁶ are preferably hydrogen. In one embodiment, m represents an integer preferably selected from 0, 1, or 2. In one embodiment, the preparation of a compound of formula (I) is carried out by reacting a compound of formula (VII) and (VIII) or of salts thereof, in the presence of a suitable acid and optionally in the presence of a solvent at a reaction temperature and for a duration, which affords sufficient formation of a compound of formula (I) or of salts thereof. The suitable acid in the preparation of a compound of formula (I) in step-A is selected in a non-limited way from the group consisting of mineral acids, organic acids, Lewis acids, and halides. The mineral acids include but are not limited to hydrochloric acid, hydrobromic acid, hydrofluoric acid, sulphuric acid, nitric acid, phosphoric acid, and perchloric acid. Organic acids include but are not limited to formic acid, acetic acid, trifluoroacetic acid, sulphonic acid, benzenesulfonic acid, p-toluene sulphonic acid, and methanesulphonic acid. The Lewis acids include but are not limited to barium fluoride, barium chloride, zinc chloride, aluminium chloride, ferric chloride, titanium chloride, magnesium chloride, copper chloride, silicon tetrafluoride, stannous chloride, and stannous fluoride. The halides include but are not limited to SOCl2, SO2Cl2, COCl2, (COCl)2, C(=O)(OCCl3)2, POX3, PX3, PX5 or metal halides; wherein X is Cl, Br, I or F. Preferably, the suitable acid is selected from SOCl2, SO2Cl2, COCl2, (COCl)2, or POX3. The halide is a binary phase, of which one part is a halogen atom and the other part is an element or radical that is less electronegative (or more electropositive) than the halogen. The suitable solvent used for the preparation of a compound of formula (I) is selected in a non-limiting way from the group consisting of aliphatic, alicyclic or aromatic hydrocarbons, halogenated hydrocarbons, ethers, nitriles, amides, sulphoxides, and sulphones or mixture thereof; aliphatic hydrocarbons are selected from but not limited to petroleum ether, n-hexane, n-heptane, octane, and the like; alicyclic hydrocarbon like cycloalkanes are selected from but not limited to cyclohexane, methylcyclohexane, cycloheptane, cyclooctane, and the like; aromatic hydrocarbons are selected from but not limited to benzene, toluene, xylene, and the like or mixtures thereof; halogenated hydrocarbons are selected from but not limited to chlorobenzene, dichlorobenzene, dichloromethane, chloroform, tetrachloromethane, dichloroethane trichloroethane, and the like or mixtures thereof; ethers are selected from but not limited to diethyl ether, diisopropyl ether, methyl tert-butyl ether, methyl tert-amyl ether, 1,4-dioxane, tetrahydrofuran, 2-methyl tetrahydrofuran, 1,2-dimethoxyethane, 1,2-diethoxyethane, cyclopentylmethylether, anisole, and the like or mixture thereof; nitriles are selected from but not limited to acetonitrile, propionitrile, n- and isobutyronitrile, benzonitrile, and the like or mixture thereof; amides are selected from but not limited to N,N-dimethylformamide, N,N-dimethylacetamide, N- methylformanilide, N-methylpyrrolidone, and the like or mixture thereof; sulphoxides are selected from but not limited to dimethyl sulphoxide and the like; sulphones are selected from but not limited to sulpholane, and the like; alcohols are selected from but not limited to methanol, ethanol, propanol, isopropanol, butanol, isobutanol, tert-butanol, amyl alcohol, and the like or mixtures thereof. In one embodiment, solvents used for the preparation of a compound of formula (I) in step-A are preferably selected from toluene, xylene, chlorobenzene, and dichlorobenzene. The reaction time is not critical and depends on the batch size, the temperature, the reagents, and the solvents being employed. Typically, the reaction time may vary from a few minutes to several hours. In one embodiment, the preparation of a compound of formula (I) in step-A is carried out at a temperature in the range of 0 ℃ to 150 ℃. It is also possible to carry out this reaction at higher or lower temperatures. In one embodiment, the preparation of a compound of formula (I) in step-A is carried out at a preferable temperature in the range of 25 ℃ to 100 ℃. In one embodiment, step-A comprises a solvent is selected from toluene, xylene, chlorobenzene or dichlorobenzene; an acid is selected from SOCl2, SO2Cl2, COCl2, (COCl)2, POCl3, POBr3, PCl3 or PCl5; the reaction temperature ranges from 0 ℃ to 150 ℃. The key intermediate compound of formula (VII) or of salts thereof, required in the preparation of a compound of formula (I) or of salts thereof, can be prepared by one or more methods as per scheme-a to scheme-c. In one embodiment, the preparation of an intermediate compound of formula (VII) or of salts thereof as per scheme-a is carried out by reacting a compound of formula (IV) or of salts thereof with a compound of formula (XII) or of salts thereof in the presence of a suitable metal complex/salt and in the presence of a suitable solvent and at a suitable reaction temperature, which affords sufficient formation of a compound of formula (VII) or of salts thereof. In another embodiment, the preparation of an intermediate compound of formula (VII) or of salts thereof as per scheme-a, is carried out by reacting a compound of formula (IV) or of salts thereof with a compound of formula (XII) or of salts thereof, in the presence of a suitable metal triflate salt, a suitable solvent and at a reaction temperature, which affords sufficient formation of a compound of formula (VII) or of salts thereof. The suitable triflate salt in scheme-a is selected in a non-limiting way from the group consisting of lithium trifluoromethanesulfonate, barium trifluoromethanesulfonate, bismuth(III) trifluoromethanesulfonate, calcium trifluoromethanesulfonate, magnesium trifluoromethanesulfonate, aluminium trifluoromethanesulfonate, scandium(III) trifluoromethanesulfonate, copper(II) trifluoromethanesulfonate, iron(II) trifluoromethanesulfonate, yttrium(III) trifluoromethanesulfonate, zinc trifluoromethanesulfonate, (4-nitrophenyl)(phenyl)iodonium trifluoromethanesulfonate, bis(4- fluorophenyl)iodonium trifluoromethanesulfonate, (2-bromoethyl)diphenylsulfonium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3- methylimidazolium trifluoromethanesulfonate, 1-fluoro-2,4,6-trimethylpyridinium trifluoromethanesulfonate, 1-fluoropyridinium trifluoromethanesulfonate, bis(4-tert- butylphenyl)iodonium trifluoromethanesulfonate, and 1-butyl-2,3-dimethylimidazolium trifluoromethanesulfonate. Preferably, the triflate salt is zinc trifluoromethanesulfonate. The reaction time is not critical and depends on the batch size, the temperature, the reagents, and solvents employed. Typically, the reaction time may vary from a few minutes to several hours. The reaction as per scheme-a is carried out at a temperature in the range of 0℃ to 100 ℃, optionally under an inert atmosphere. Preferably, the reaction temperature ranges from 0 ℃ to 50 ℃. The suitable solvents for scheme-a are selected from the solvents as provided for the preparation of a compound of formula (I). Preferably, the solvents are selected from 1,4-dioxane, tetrahydrofuran, 2- methyl tetrahydrofuran, 1,2-dimethoxyethane, 1,2-diethoxyethane, N,N-dimethylformamide, N,N- dimethylacetamide or nitromethane, and the like. In yet another embodiment, scheme-a comprises a metal salt which is selected from zinc trifluoromethanesulfonate, iron(II) trifluoromethanesulfonate, yttrium(III) trifluoromethanesulfonate, calcium trifluoromethanesulfonate, magnesium trifluoromethanesulfonate, aluminium trifluoromethanesulfonate or scandium(III) trifluoromethanesulfonate; a solvent is selected from 1,4- dioxane, tetrahydrofuran, 2-methyl tetrahydrofuran, 1,2-dimethoxyethane, 1,2-diethoxyethane, N,N- dimethylformamide, N,N-dimethylacetamide or nitromethane; the reaction temperature ranges from 0 ℃ to 100 ℃. Alternatively, the compound of formula (VII) or of salts thereof can be prepared by scheme-b; comprising of (step-1) reacting a compound of formula (IV) or of salts thereof, with a compound of formula (XII) or of salts thereof in the presence of a suitable Lewis acid and optionally in the presence of a solvent to obtain a compound of formula (VI) or of salts thereof; which in a subsequent step (step- 2) is converted into a compound of formula (VII) or of salts thereof using a suitable reducing reagent, a suitable acid and in the presence of a suitable solvent. The suitable Lewis acid for step-1 of scheme-b is selected in a non-limiting way from the group consisting of barium fluoride, barium chloride, zinc chloride, zinc bromide, aluminium chloride, magnesium chloride, copper chloride, ferric chloride, silicon tetrafluoride, stannous chloride, titanium chloride, and stannous fluoride. Preferably, the Lewis acid is selected from zinc chloride, aluminium chloride, ferric chloride, magnesium chloride, or copper chloride. The optional solvent for step-1 of scheme-b is selected from aliphatic, alicyclic, or aromatic hydrocarbons, such as cyclohexane, methylcyclohexane, benzene, toluene, xylene, nitrobenzene, chlorobenzene, and decalin or mixture thereof. Preferably, the step-1 of scheme-b is carried out in the absence of solvent. The reaction as per step-1 of scheme-b is carried out at a temperature in the range of 25℃ to 150 ℃. Preferably, the reaction temperature ranges from 70 ℃ to 120 ℃. The suitable reducing agent for step-2 of scheme-b is selected in a non-limiting way from the group consisting of sodium borohydride, sodium cyanoborohydride, zinc borohydride, zinc amalgam, lithium aluminium hydride (LiAlH ₄ ), triethylsilane, diborane, and sodium amalgam. Preferably, the reducing agent is triethylsilane. The suitable acid for step-2 of scheme-b is selected in a non-limiting way from the group consisting of methanesulphonic acid, trifluoroacetic acid, triflic acid or borontrifluoride diethyl etherate. Preferably, the acid is selected from borontrifluoride diethyl etherate or triflic acid. The suitable solvents for step-2 of scheme-b are selected from the solvents as provided for the preparation of a compound of formula (I) or of salts thereof. Preferably, the solvents are selected from chlorobenzene, dichlorobenzene, dichloromethane, chloroform, acetonitrile, propionitrile, n- and isobutyronitrile, benzonitrile, diethyl ether, diisopropyl ether or methyl tert-butyl ether. The reaction as per step-2 of scheme-b is carried out at a temperature in the range of 0 ℃ to 70 ℃. Preferably, the reaction temperature ranges from 0 ℃ to 50 ℃. The reaction time for step-1 and step-2 of scheme-b is not critical and depends on the batch size, the temperature, the reagents, and solvents being employed. Typically, the reaction time may vary from a few minutes to several hours. In one embodiment, the preparation of a compound of formula (VII) or of salts thereof, by following reaction scheme-b, may be performed with or without the isolation of the intermediate compound (VI) or of salts thereof. In another embodiment, step-1 of scheme-b comprises a Lewis acid which is selected from zinc chloride, aluminium chloride, ferric chloride, magnesium chloride or copper chloride; the reaction temperature ranges from 25 ℃ to 150 ℃; step-2 of scheme-b comprises a reducing agent which is selected from sodium borohydride, sodium cyanoborohydride, triethyl silane or diborane; a solvent is selected from chlorobenzene, dichlorobenzene, dichloromethane, chloroform, acetonitrile, propionitrile, n- and isobutyronitrile, benzonitrile, diethyl ether, diisopropyl ether or methyl tert-butyl ether; a suitable acid is selected from methanesulphonic acid, trifluoroacetic acid, triflic acid or borontrifluoride diethyl etherate; the reaction temperature ranges from 0 ℃ to 70 ℃. Alternatively, the compound of formula (VII) or of salts thereof can be prepared as per scheme-c; comprising of (step-1) reacting a compound of formula (IVa) or of salts thereof, with a compound of formula (XIIa) or of salts thereof in the presence of a suitable organometallic compound, in the presence of a suitable solvent and at a suitable temperature to obtain a compound of formula (VIa) or of salts thereof; which in a subsequent step (step-2) is converted into a compound of formula (VII) or into salts thereof using a suitable reducing reagent, a suitable acid and in the presence of a suitable solvent. The reaction as per step-1 of scheme-c is carried out at a suitable temperature in the range of -100 ℃ to 25 ℃. Preferably, the reaction temperature ranges from -70 ℃ to 25℃. The suitable organometallic compound for step-1 of scheme-c is selected from organo lithium reagents such as n-butyl lithium, n-hexyl lithium, lithium diisopropylamide (LDA), or Grignard reagents. The suitable solvents for step-1 of scheme-c are selected from solvents as provided for the preparation of a compound of formula (I). Preferably, the solvents are selected from diethyl ether, diisopropyl ether, methyl tert-butyl ether, methyl tert-amyl ether, tetrahydrofuran, or 2-methyl tetrahydrofuran. The suitable reducing agent for step-2 of scheme-c is selected in a non-limiting way from the group consisting of sodium borohydride, sodium cyanoborohydride, zinc borohydride, zinc amalgam, lithium aluminium hydride (LiAlH4), triethylsilane, diborane, and sodium amalgam. Preferably, the reducing agent is triethylsilane. The suitable acid for step-2 of scheme-c is selected in a non-limiting way from the group consisting of methanesulphonic acid, trifluoroacetic acid, triflic acid or borontrifluoride diethyl etherate. Preferably, the acid is triflic acid. The suitable solvents for step-2 of scheme-c are selected from solvents as provided for the preparation of a compound of formula (I). Preferably, the solvents are selected from chlorobenzene, dichlorobenzene, dichloromethane, chloroform, acetonitrile, propionitrile, n- and isobutyronitrile, benzonitrile, diethyl ether, diisopropyl ether or methyl tert-butyl ether. The reaction temperature for performing the reaction step-2 of scheme-c may vary from 0 ℃ to 50 ℃. The reaction time for step-1 and step-2 of scheme-c is not critical and depends on the batch size, the temperature, the reagents and solvents being employed. Typically, the reaction time may vary from a few minutes to several hours. In one embodiment, step-1 of scheme-c comprises an organometallic compound which is selected from n-butyl lithium, n-hexyl lithium, lithium diisopropylamide, or Grignard reagents; a solvent is selected from diethyl ether, diisopropyl ether, methyl tert-butyl ether, methyl tert-amyl ether, tetrahydrofuran or 2-methyl tetrahydrofuran and, the reaction temperature ranges from -100 ℃ to 25 ℃; step-2 of scheme- c comprises a reducing agent is selected from sodium borohydride, sodium cyanoborohydride, zinc borohydride, zinc amalgam, lithium aluminium hydride (LiAlH ₄ ), triethylsilane, diborane, and sodium amalgam; a solvent is selected from chlorobenzene, dichlorobenzene, dichloromethane, chloroform, acetonitrile, propionitrile, n- and isobutyronitrile, benzonitrile, diethyl ether, diisopropyl ether or methyl tert-butyl ether; a suitable acid is selected from methanesulphonic acid, trifluoroacetic acid, triflic acid or borontrifluoride diethyl etherate; the reaction temperature ranges from 0 ℃ to 50 ℃. In one embodiment, the preparation of a compound of formula (VII) or of salts thereof, as per the reaction scheme-c, may be performed with or without isolation of the intermediate compound (VIa) or of salts thereof. In one embodiment, the preparation of the compounds of formula (I) or (VII) or of salts thereof may involve the isolation of respective reaction intermediates after the completion of the reaction. However, the reaction steps can also proceed to the next steps without isolation of the respective reaction intermediates. The processes as disclosed in the present invention are preferably carried out batch-wise. However, semi-continuous or continuous reaction passages, for instance under flow reaction conditions, are also possible. The processes as disclosed in the present invention can be run in the absence of a solvent or in the presence of one or more suitable solvents. The optional solvent should be resistant against undesired side reactions, e.g., oxidation (i.e. a solvent will be preferred whose rate of oxidation is substantially lower than that of the compounds of formula (I) to (VIII) and suitable for suspending, or preferably dissolving the reactants. 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 a solvent, further optionally drying of the product if required. The isolation of the reaction product can also be carried out by a technique which includes but is not limited to decantation, centrifugation, evaporation, ultrafiltration, liquid-liquid extraction, distillation, recrystallization, chromatography, and the like. The process steps according to the invention are generally carried out under atmospheric pressure. Alternatively, however, it is also possible to work under reduced pressure or under pressure. Applications: According to the above description, reaction step-A for the synthesis of a compound of formula (I) can also be used to obtain a compound of formula (Z): (Z) wherein, R ¹ and R ² are independently selected from the group consisting of C1-C6-alkyl, C3-C6-cycloalkyl-C1- C3-alkyl, and C3-C6-cycloalkyl; preferably R ¹ is methyl and R ¹ is ethyl. R ³ and R ⁴ are independently selected from the group consisting of halogen, cyano, C1-C6-alkyl, C1-C6- haloalkyl, C1-C6-alkoxy, and C3-C6-cycloalkyl; A represents -{[C(R ⁵ R ⁶ )]0-2-(Y)0-1}-, -{[C(R ⁵ R ⁶ )]0-1-(Y)0-1-C(=G)}- or -{[Y-C(R ⁵ R ⁶ )]0-1-C(=G)}-; wherein Y represent O, S or NR ⁵ ; and G represents O or S; R ⁵ and R ⁶ are independently selected from the group consisting of hydrogen, X, C1-C6-alkyl, C1-C6- haloalkyl, and C3-C8-cycloalkyl; wherein one or more carbon atoms in cycloalkyl ring may be replaced by heteroatoms selected from the group consisting of N, O, S(O)m and optionally including 1 to 3 ring members selected from the group consisting of C(=O) or C(=S); or R ⁵ and R ⁶ together with the carbon atom to which they are attached may form a =O or cyclopropyl ring; R ⁷ is selected from the group consisting of hydrogen, halogen, cyano, nitro, C1-C6-alkyl, C1-C6- haloalkyl, C1-C6-alkoxy, C1-C6-alkylthio, C1-C6-alkylsulfinyl, C1-C6-alkylsulfonyl, C3-C6-cycloalkyl, and C3-C6-cycloalkyl-C1-C3-alkyl; wherein R ⁷ optionally substituted with halogen, cyano, C1-C4-alkyl or C1-C4-alkoxy; R′ is selected from the group consisting of hydrogen, C ₁ -C ₈ -alkyl and C ₃ -C ₈ -cycloalkyl; wherein alkyl and cycloalkyl groups may be optionally substituted by one or more X; R″ is selected from the group consisting of hydrogen, C ₁ -C ₈ -alkyl, C ₁ -C ₈ -haloalkyl, C ₃ -C ₈ -cycloalkyl, N(R′)2, OR′, and C6-C18-aryl; wherein one or more carbon atoms in cyclic ring may be replaced by heteroatoms selected from the group consisting of N, O, S(O) _m and optionally including 1 to 3 ring members selected from the group consisting of C(=O) or C(=S); m represents an integer selected from 0 to 4; X represents halogen; and salts, N-oxides, metal complexes or stereo-isomers thereof. In one embodiment, the present invention provides a process for preparing a compound of formula (Z) (Z) wherein, R ¹ and R ² are independently selected from the group consisting of C1-C6-alkyl, C3-C6-cycloalkyl-C1- C3-alkyl, and C3-C6-cycloalkyl; preferably R ¹ is methyl and R ¹ is ethyl. R ³ and R ⁴ are independently selected from the group consisting of halogen, cyano, C1-C6-alkyl, C1-C6- haloalkyl, C1-C6-alkoxy, and C3-C6-cycloalkyl; A represents -{[C(R ⁵ R ⁶ )]0-2-(Y)0-1}-, -{[C(R ⁵ R ⁶ )]0-1-(Y)0-1-C(=G)}- or -{[Y-C(R ⁵ R ⁶ )]0-1-C(=G)}-; wherein Y represent O, S or NR ⁵ ; and G represents O or S; R ⁵ and R ⁶ are independently selected from the group consisting of hydrogen, X, C1-C6-alkyl, C1-C6- haloalkyl, and C3-C8-cycloalkyl; wherein one or more carbon atoms in cycloalkyl ring may be replaced by heteroatoms selected from the group consisting of N, O, S(O)m and optionally including 1 to 3 ring members selected from the group consisting of C(=O) or C(=S); or R ⁵ and R ⁶ together with the carbon atom to which they are attached may form a =O or cyclopropyl ring; R ⁷ is selected from the group consisting of hydrogen, halogen, cyano, nitro, C1-C6-alkyl, C1-C6- haloalkyl, C1-C6-alkoxy, C1-C6-alkylthio, C1-C6-alkylsulfinyl, C1-C6-alkylsulfonyl, C3-C6-cycloalkyl, and C3-C6-cycloalkyl-C1-C3-alkyl; wherein R ⁷ optionally substituted with halogen, cyano, C1-C4-alkyl or C1-C4-alkoxy; R′ is selected from the group consisting of hydrogen, C1-C8-alkyl and C3-C8-cycloalkyl; wherein alkyl and cycloalkyl groups may be optionally substituted by one or more X; R″ is selected from the group consisting of hydrogen, C ₁ -C ₈ -alkyl, C ₁ -C ₈ -haloalkyl, C ₃ -C ₈ -cycloalkyl, N(R′) ₂ , OR′, and C ₆ -C ₁₈ -aryl; wherein one or more carbon atoms in cyclic ring may be replaced by heteroatoms selected from the group consisting of N, O, S(O) _m and optionally including 1 to 3 ring members selected from the group consisting of C(=O) or C(=S); m represents an integer selected from 0 to 4; X represents halogen; and salts, N-oxides, metal complexes or stereo-isomers thereof; comprising the step-B of: reacting a compound of formula (Z ^A ) or of salts thereof, wherein, R ⁸ is selected from the group consisting of C ₁ -C ₆ -alkyl, C ₁ -C ₆ -alkoxy, and C ₁ -C ₆ -haloalkyl; m, A, R ³ , R ⁴ , and R ⁷ are as defined above, with a compound of formula (VIII) or of salts thereof, wherein, R ¹ and R ² are as defined above, in the presence of a suitable acid and optionally in the presence of a solvent as shown in the below scheme: wherein, m, A, R ¹ , R ² , R ³ , R ⁴ , R ⁷ , and R ⁸ are as defined above. In one embodiment, A is selected from the group consisting of -O-, -S-, -NR ⁵ -, -C(=O)-, -OC(=O)-, - C(R ⁵ R ⁶ )C(=O)-, -OC(R ⁵ R ⁶ )C(=O)-, -SC(R ⁵ R ⁶ )C(=O)-, -NR ⁵ C(R ⁵ R ⁶ )C(=O)-, -C(R ⁵ R ⁶ )NR ⁵ C(=O)-, - C(R ⁵ R ⁶ )O-, -C(R ⁵ R ⁶ )S-, -C(R ⁵ R ⁶ )NR ⁵ -, -(C=O)C(R ⁵ R ⁶ )O-, -(C=O)C(R ⁵ R ⁶ )-,-(C=O)C(R ⁵ R ⁶ )S-, and - (C=O)C(R ⁵ R ⁶ )NR ⁵ -. In one embodiment, step-B for the preparation of a compound of formula (Z) comprises a solvent which is selected from toluene, xylene, chlorobenzene or dichlorobenzene; an acid is selected from SOCl2, SO2Cl2, COCl2, (COCl)2, POCl3, POBr3, PCl3 or PCl5; the reaction temperature ranges from 0 ℃ to 150 ℃. In one embodiment, the substituents R ⁵ and R ⁶ are preferably hydrogen. In one embodiment, the preparation of a compound of formula (Z) in step-B is carried out at a preferable temperature in the range of 25 ℃ to 100 ℃. In one embodiment, R ⁸ is preferably selected from methyl, methoxy, ethoxy, propoxy, 1-methylethoxy, butoxy, 1-methylpropoxy or halomethyl. Without further elaboration, it is believed 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 the disclosure in any way whatsoever. Examples: A) Preparation of a compound of formula (I) from a compound of formula (VII): Example 1: Preparation of N'-(2,5-dimethyl-4-(2-methylbenzyl)phenyl)-N-ethyl-N- methylformimidamide. Method-1: To a stirred solution of N-(2,5-dimethyl-4-(2-methylbenzyl)phenyl)acetamide (0.4 g, 1.5 mmol) and phosphorus oxychloride (0.139 mL, 1.5 mmol) in toluene (4 mL), N-ethyl-N-methylformamide (0.130 g, 1.5 mmol) was added at 25 ° C. The reaction mixture was then stirred at 100 ℃ for 1 h. The reaction mixture was quenched by the addition of water (10 mL). Triethyl amine (2 mL) was added till the reaction mixture was neutralized. The reaction mixture was extracted with ethyl acetate (20 mL). The organic layer was washed with brine (40 mL), dried over anhydrous sodium sulphate and concentrated under reduced pressure to obtain a crude product which was purified by column chromatography on silica gel to obtain N'-(2,5-dimethyl-4-(2-methylbenzyl)phenyl)-N-ethyl-N-methylf ormimidamide (0.27 g, 61.3 % yield ). ¹ H-NMR (400 MHz, DMSO-d6) δ 7.59 (s, 1H), 7.17-7.14 (m, 1H), 7.10-7.03 (m, 2H), 6.80-6.77 (m, 1H), 6.59 (d,2H), 3.78 (d,2H), 3.42-3.35 (m, 1H), 3.29 (s, 1H), 2.90 (s, 3H), 2.22 (s, 3H), 2.09 (s, 3H), 2.04 (s, 3H), 1.10 (t, 3H); LCMS (M+1):295.1. Method-2: To a stirred solution of N-(2,5-dimethyl-4-(2-methylbenzyl)phenyl)acetamide (0.200 g, 0.75 mmol) and oxalyl chloride (0.095 g, 0.75 mmol) in toluene (5 ml), N-ethyl-N-methylformamide (0.130 g, 1.45 mmol) was added at 25 ℃. The reaction mixture was then stirred at 100 ℃ for 1 h. After completion of the reaction, the reaction mixture was quenched by the addition of water (5 mL). Triethyl amine (1 mL) was added till the reaction mixture was neutralized, followed by extraction with ethyl acetate (20 mL). The organic layer was washed with brine (40 mL), dried over anhydrous sodium sulphate and concentrated under reduced pressure to obtain a crude product which was purified by column chromatography on silica gel to obtain N'-(2,5-dimethyl-4-(2-methylbenzyl)phenyl)-N-ethyl-N- methylformimidamide (0.12 g, 54.5 % yield). ¹ H-NMR (400 MHz, DMSO-d ₆ ) δ 7.59 (s, 1H), 7.17-7.14 (m, 1H), 7.10-7.03 (m, 2H), 6.80-6.77 (m, 1H), 6.59 (d,2H), 3.78 (d,2H), 3.42-3.35 (m, 1H), 3.29 (s, 1H), 2.90 (s, 3H), 2.22 (s, 3H), 2.09 (s, 3H), 2.04 (s, 3H), 1.10 (t, 3H); LCMS (M+1):295.1. Method-3: To a stirred solution of methyl (2,5-dimethyl-4-(2-methylbenzyl)phenyl)carbamate (0.47 g, 1.67 mmol) in toluene (10 mL), phosphorous oxychloride (0.19 mL, 2.011 mmol) and N-ethyl-N-methylformamide (0.22 g, 2.51 mmol) were added at 25 °C and the mixture was stirred at 80 °C for 5 h. After completion of the reaction, the reaction mixture was cooled to 25 °C, quenched by addition of cold water (10 mL) and triethylamine (2 mL) and extracted with ethyl acetate (2 x 10 mL). The combined organic layers were washed with brine (10 mL), dried over anhydrous sodium sulphate and concentrated under reduced pressure to obtain a crude product which was purified by column chromatography on silica gel to obtain N'-(2,5-dimethyl-4-(2-methylbenzyl)phenyl)-N-ethyl-N-methylf ormimidamide (0.120 g, 0.41 mmol, 24.31 % yield). ¹ H-NMR (400 MHz, CDCl3) δ 7.44 (bs, 1H), 7.19 – 7.07 (m, 3H), 6.85 (d, 1H), 6.70 (bs, 1H), 6.60 (bs, 1H), 3.82 (s, 2H), 3.39 (bs, 2H), 3.01 (s, 3H), 2.29 (s, 3H), 2.18 (s, 3H), 1.12 (t, 3H). LCMS (M+H): 295.35. Example 2: Preparation of N'-(2,5-dimethyl-4-(2-nitrobenzyl)phenyl)-N-ethyl-N- methylformimidamide. To a stirred solution of N-(2,5-dimethyl-4-(2-nitrobenzyl)phenyl)acetamide (4.0 g, 13.4 mmol) and phosphorus oxychloride (1.25 ml, 13.4 mmol) in toluene (40 mL), N-ethyl-N-methylformamide (1.40 g, 16.09 mmol) was added at 25 ℃. The reaction mixture was then stirred at 100 ℃ for 1 h. After completion of the reaction, the reaction mixture was quenched by the addition of water (50 mL). Triethyl amine (12 mL) was added till the reaction mixture was neutralized followed by extraction with ethyl acetate (20 mL). The organic layer was washed with brine (40 mL), dried over anhydrous sodium sulphate and concentrated under reduced pressure to obtain a crude product which was purified by column chromatography on silica gel to obtain N'-(2,5-dimethyl-4-(2-nitrobenzyl)phenyl)-N-ethyl-N- methylformimidamide (2.8 g, 64.2 % yield). ¹ H-NMR (400 MHz, DMSO-d ₆ ) δ 7.95 (dd, 1H), 7.61-7.47 (m, 3H), 7.14 (d, 1H), 6.61 (d, 2H), 4.09 (s, 2H), 3.35 (m,2H), 2.90 (s, 3H), 2.04 (s, 6H), 1.10 (t, 3H); LCMS (M+1):326.2. Example 3: Preparation of N'-(4-(2-bromobenzyl)-2,5-dimethylphenyl)-N-ethyl-N- methylformimidamide. To a stirred solution of N-(4-(2-bromobenzyl)-2,5-dimethylphenyl)acetamide (6.0 g, 18.06 mmol) and phosphorus oxychloride (1.7 ml, 18.06 mmol) in toluene (60 mL), N-ethyl-N-methylformamide (1.9 g, 21.67 mmol) was added at 25 ℃. The reaction mixture was then stirred at 100 ℃ for 1 h. After completion of the reaction, the reaction mixture was quenched by the addition of water (50 mL). Triethyl amine (12 mL) was added till the reaction mixture was neutralized, followed by extraction with ethyl acetate (20 mL). The organic layer was washed with brine (40 mL), dried over anhydrous sodium sulphate and concentrated under reduced pressure to obtain a crude product which was purified by column chromatography on silica gel to obtain N'-(4-(2-bromobenzyl)-2,5-dimethylphenyl)-N-ethyl-N- methylformimidamide (4.8 g, 74% yield). 1H-NMR (400 MHz, DMSO-d ₆ ) δ 7.64-7.56 (m, 2H), 7.26 (td, 1H), 7.14 (td, 1H), 6.91 (dd, 1H), 6.67 (s, 1H), 6.60 (s, 1H), 3.88 (s, 2H), 3.34-3.49 (m, 2H), 2.91 (s, 3H), 2.07 (s, 6H), 1.11 (t, 3H); LCMS (M+1): 360.55. Example 4: Preparation of N'-(2-chloro-4-(2,4-difluorobenzyl)-5-methylphenyl)-N-ethyl- N- methylformimidamide. To a stirred solution of N-(2-chloro-4-(2,4-difluorobenzyl)-5-methylphenyl)acetamide (1.0 g, 3.23 mmol) and phosphorus oxychloride (0.301 mL, 3.23 mmol) in toluene (10 mL), N-ethyl-N- methylformamide (0.34 g, 3.87 mmol) was added at 25 ℃. The reaction mixture was then stirred at 100 ℃ for 1 h. After completion of the reaction, the reaction mixture was quenched by the addition of water (50 mL). Triethyl amine (12 mL) was added till the reaction mixture was neutralized, followed by extraction with ethyl acetate (20 mL). The organic layer was washed with brine (20 mL), dried over anhydrous sodium sulphate and concentrated under reduced pressure to obtain a crude product which was purified by column chromatography on silica gel to obtain N'-(2-chloro-4-(2,4-difluorobenzyl)-5- methylphenyl)-N-ethyl-N-methylformimidamide (0.9 g, 83 % yield). ¹ H-NMR (400 MHz, DMSO-d ₆ ) δ 7.64 (bs, 1H), 7.33 (dd, 1H), 7.18-7.14 (m, 1H), 7.10 (s, 1H), 6.95 (s, 2H), 6.78 (s, 3H), 3.86 (s,2H), 3.41 (m, 2H), 2.97 (s, 3H), 2.10 (s, 3H); LCMS (M+1):337.15. Example 5: Preparation of N-ethyl-N'-(4-(2-fluorobenzyl)-2,5-dimethylphenyl)-N- methylformimidamide. To a stirred solution of N-(2-chloro-4-(2,4-difluorobenzyl)-5-methylphenyl)acetamide (1.0 g, 3.69 mmol) and phosphorus oxychloride (0.41 ml, 4.42 mmol) in toluene (10 mL), N-ethyl-N- methylformamide (0.64 g, 7.37 mmol) was added at 25 ℃. The reaction mixture was then stirred at 100 ℃ for 1 h. After completion of the reaction, the reaction mixture was quenched by the addition of water (50 mL). Triethyl amine (12 mL) was added till the reaction mixture was neutralized, followed by extraction with ethyl acetate (20 mL). The organic layer was washed with brine (40 mL), dried over anhydrous sodium sulphate and concentrated under reduced pressure to obtain a crude product which was purified by column chromatography on silica gel to obtain N-ethyl-N'-(4-(2-fluorobenzyl)-2,5- dimethylphenyl)-N-methylformimidamide (0.84 g, 76 % yield). 1H-NMR (400 MHz, DMSO- d6)) δ 7.55 (d, 1H), 7.26-7.20 (m, 1H), 7.17-7.12 (m, 1H), 7.08 (td, 1H), 7.03-6.99 (m, 1H), 6.78 (s, 1H), 6.56 (s, 1H), 3.83 (s, 2H), 3.41 (d,2H), 2.90 (s, 3H), 2.13 (s, 3H), 2.07 (s, 3H), 1.10 (t, 3H); LCMS(M+1): 298.80. B) Preparation of a compound of formula (VII): Example 6: Preparation of N-ethyl-N-methylformamide intermediate. To a stirred solution of N-methylethanamine (14.71 mL, 169 mmol) in ethanol (30 mL), ethyl formate (21.21 ml, 372 mmol) was added. The reaction mixture was stirred at 65 ℃ for 2 h. The volatiles were removed under reduced pressure to obtain crude N-ethyl-N-methylformamide (12.0 g, 81 %). ¹ H-NMR (400 MHz, DMSO-d ₆ ) δ: 8.07-7.99 (m, 1H), 3.40-3.29 (m, 2H), 3.25-2.85 (m, 3H), 1.90-1.10 (m, 3H); GCMS: (M ⁺ ) 87. Example 7: Preparation of N-(2,5-dimethyl-4-(2-methylbenzyl)phenyl)acetamide intermediate. Step-(i): Preparation of N-(2,5-dimethyl-4-(2-methylbenzoyl)phenyl)acetamide. To a stirred mixture of N-(2,5-dimethylphenyl)acetamide (50 g, 306 mmol), aluminium chloride (102 g, 766 mmol) and 2-methylbenzoyl chloride (100 mL, 766 mmol) were added at 25 ℃ and the mixture was heated at 100 ℃ and this temperature was maintained till completion of the reaction. After completion of the reaction, the reaction mixture was quenched by addition of 1N hydrochloric acid (approx. 250 mL till a clear solution was obtained). The reaction mixture was extracted with 1,2- dichloromethane (500 mL x 2). The combined organic layers were washed with water (500 mL x 3), followed by brine (250 mL), dried over anhydrous sodium sulphate and concentrated under reduced pressure to obtain a crude product which was purified by column chromatography on silica gel to obtain N-(2,5-dimethyl-4-(2-methylbenzyl)phenyl)acetamide (70 g, 81 % yield ). LCMS (M+H): 281.4. Step-(ii): Preparation of N-(2,5-dimethyl-4-(2-methylbenzyl)phenyl)acetamide. Method-1: Triethylsilane (79 mL, 498 mmol) was added to a suspension of N-(2,5-dimethyl-4-(2- methylbenzoyl)phenyl)acetamide (35 g, 124 mmol) in acetonitrile (150 mL), followed by the addition of borontrifluoride diethyl etherate (63.1 mL, 498 mmol) over a period of 10 min at 0 ℃. The reaction mixture was stirred at 25 ℃ for 36 h. After completion of the reaction, the reaction mixture was neutralized to pH 7-8 with solid sodium bicarbonate and then extracted with dichloromethane (200 mL x 3). The combined organic layers were dried over anhydrous sodium sulphate and concentrated under reduced pressure to obtain a crude product which was purified by column chromatography on silica gel to obtain N-(2,5-dimethyl-4-(2-methylbenzyl)phenyl)acetamide (12 g, 36.1 % ). 1H-NMR (400 MHz, DMSO- d ₆ ) δ 9.32 (s, 1H), 7.21-7.18 (m, 2H), 7.18-7.16 (m, 2H), 6.80 (d, J = 7.3 Hz, 1H), 6.68 (s, 1H), 3.85 (s, 2H), 2.20 (s, 3H), 2.08( s, 3H), 2.01 (s, 3H), 1.95 (s, 3H); LCMS (M+H) 268.3. Method-2: To an ice cold solution of N-(2,5-dimethyl-4-(2-methylbenzoyl)phenyl)acetamide (100 g, 355 mmol) and triflic acid (126 mL, 1422 mmol) in dichloromethane (1000 mL), triethylsilane (227 ml, 1422 mmol) was added drop wise at 0 ℃. The reaction mixture was then slowly allowed to warm to 25 ℃ and stirred at 25 ℃ for 2 h. After completion of the reaction, the reaction mixture was quenched by addition of an ice-cold aqueous 5% sodium bicarbonate solution (500 mL) and then extracted with dichloromethane (500 mL x 3). The combined organic layers were dried over anhydrous sodium sulphate and concentrated under reduced pressure to obtain a crude product. The crude product was then stirred in dichloromethane (150 mL) and hexane (700 mL). The solid was filtered to obtain N-(2,5- dimethyl-4-(2-methylbenzyl)phenyl)acetamide (86 g, 90% yield ). 1H-NMR (400 MHz, DMSO- d6) δ 9.32 (s, 1H), 7.21-7.18 (m, 2H), 7.18-7.16 (m, 2H), 6.80 (d, J = 7.3 Hz, 1H), 6.68 (s, 1H), 3.85 (s, 2H), 2.20 (s, 3H), 2.08(s, 3H), 2.01 (s, 3H), 1.95 (s, 3H); LCMS (M+H) 268.3. Example-8: Preparation of N-(2,5-dimethyl-4-(2-methylbenzyl)phenyl)acetamide: To a stirred solution of N-(2,5-dimethylphenyl)acetamide (0.45 g, 2.71 mmol) in 1,4-dioxane (2 mL), zinc trifluoromethanesulfonate (0.2 g, 0.55 mmol) and 1-(bromomethyl)-2-methylbenzene (0.60g, 3.25 mmol) were added and stirring was continued at 25 ℃ for 46 h. After completion of the reaction, the reaction mixture was quenched by addition of water (5 mL), followed by extraction with ethyl acetate (20 mL). The organic layer was washed with brine (10 mL), dried over anhydrous sodium sulphate and concentrated under reduced pressure to obtain a crude product which was purified by prep HPLC to obtain N-(2,5-dimethyl-4-(2-methylbenzyl)phenyl)acetamide (0.083g). LCMS (M+H): 290.75. ¹ H- NMR (400 MHz, DMSO- d6) δ 9.16 (s, 1H), 7.18 (d, J = 10.3 Hz, 2H), 7.02-7.13 (m, 2H), 6.78-6.80 (m, 1H), 6.68 (s, 1H), 3.81 (s, 2H), 2.18 (s, 3H), 2.14 (s, 3H), 2.05 (s, 3H), 2.02 (s, 3H). Example 9: Step 1: Preparation of N-(4-bromo-2-chloro-5-methylphenyl)acetamide: To a stirred solution of 4-bromo-2-chloro-5-methylaniline (5 g, 22.68 mmol) and triethylamine (7.90 mL, 56.7 mmol) in dichloromethane (50 mL), acetyl chloride (1.94 mL, 27.2 mmol) was added at 0 ℃. The reaction mixture was allowed to warm up to 25 ℃ and stirred further for 2 h. After completion of the reaction, the reaction mixture was quenched by addition of water (150 mL) and extracted with dichloromethane (200 mL x 3). The combined organic layers were washed with saturated sodium bicarbonate solution (200 mL), water (200 mL) and brine (150 mL), dried over anhydrous sodium sulphate and concentrated under reduced pressure to obtain a crude product which was purified by column chromatography on silica gel to obtain N-(4-bromo-2-chloro-5-methylphenyl)acetamide (3.93 g, 14.97 mmol, 66.0 % yield ). ¹ H-NMR (400 MHz, DMSO- d6) δ: 7.74 (s, 1H), 7.69 (s, 1H), 2.23 (s, 3H), 2.05 (s, 3H); LCMS (M+H): 263.80 Step-2: Preparation of N-(2-chloro-4-(hydroxy(o-tolyl)methyl)-5-methylphenyl)acetam ide: To a stirred solution of N-(4-bromo-2-chloro-5-methylphenyl)acetamide (0.834 g, 3.18 mmol) in tetrahydrofuran (12 mL), n-butyllithium (2.80 ml, 6.99 mmol) was added dropwise at -70 ℃ and stirring was continued at the same temperature for 1 h.2-Methyl-benzaldehyde (0.763 g, 6.35 mmol) (dissolved in 5 mL THF solution) was added drop-wise at -70 ℃, and the reaction mixture was then allowed to warm slowly to 0 ℃ over a period of 1 h. After completion of the reaction, the reaction mixture was quenched by addition of ice water (10 ml) and extracted with ethyl acetate (30 mL), washed with brine (20 mL) and concentrated under reduced pressure to obtain a crude product which was purified by column chromatography to obtain N-(2-chloro-4-(hydroxy(o-tolyl)methyl)-5-methylphenyl)acetam ide (0.312 g, 1.027 mmol, 32.3 % yield ). LCMS (M-1): 301.85. Example 10: Step 1: Preparation of methyl (2,5-dimethyl-4-(2-methylbenzyl)phenyl)carbamate: To a stirred mixture of potassium carbonate (0.84 g, 6.07 mmol), 2,5-dimethyl-4-(2- methylbenzyl)aniline (0.45 g, 2.02 mmol) in acetone (10 mL), methyl chloroformate (0.47 mL, 6.07 mmol) was added at 25 °C. The resulting reaction suspension was stirred at 40 °C for 16 h. After completion of the reaction, the mixture was cool to 25 °C and filtered. The filtrate was evaporated to dryness to obtain methyl (2,5-dimethyl-4-(2-methylbenzyl)phenyl)carbamate (0.52 g, 1.84 mmol, 91 % yield). LCMS (M+1): 284.10. Example 11: Preparation of N'-(4-(2-bromobenzoyl)-2,5-dimethylphenyl)-N-ethyl-N- methylformimidamide Step-1: Preparation of N-(4-(2-bromobenzoyl)-2,5-dimethylphenyl)acetamide To a stirred mixture of aluminium chloride (29.4 g, 221 mmol) and N-(2,5-dimethylphenyl)acetamide (12 g, 73.5 mmol), 2-bromobenzoyl chloride (11.59 mL, 88 mmol) was added at 25 °C and the reaction mixture was heated at 100 °C for 6 h. After completion of the reaction, the reaction mixture was quenched by addition of 1 N hydrochloric acid and cold water (300 mL). The reaction mixture was extracted with dichloromethane (200 mL x 2). The combined organic layers were washed with saturated aqueous sodium bicarbonate solution (100 mL) and brine (100 mL), dried over anhydrous sodium sulphate, filtered and concentrated under reduced pressure to obtain a crude product which was triturated with hexane, decanted and dried to obtain N-(4-(2-bromobenzoyl)-2,5- dimethylphenyl)acetamide (23.0 g, 66.4 mmol, 90 % yield) as pale yellow solid. LCMS (M+1): 347.45 Step 2: Preparation of N'-(4-(2-bromobenzoyl)-2,5-dimethylphenyl)-N-ethyl-N- methylformimidamide To a stirred solution of N-(4-(2-bromobenzoyl)-2,5-dimethylphenyl)acetamide (4.0 g, 11.55 mmol) in toluene (40 mL), phosphorous oxychloride (1.08 mL, 11.55 mmol) and N-ethyl-N-methylformamide (1.21 g, 13.86 mmol) was added at 25 °C. The reaction mixture was then stirred at 100 °C for 1 h. After completion of the reaction, the reaction mixture was cooled to 25 °C, quenched by addition of water (50 mL). Triethylamine (7 mL) was added till the reaction mixture was neutralized, followed by extraction with ethyl acetate (50 mL x 2). The combined organic layers were dried over anhydrous sodium sulphate and concentrated under reduced pressure to obtain a crude product which was purified by column chromatography on silica gel to obtain N'-(4-(2-bromobenzoyl)-2,5-dimethylphenyl)-N- ethyl-N-methylformimidamide (2 g, 5.36 mmol, 46.4 % yield). LCMS (M+1): 374.85 B) Preparation of a compound of formula (Z) from a compound of formula (Z ^A ): Example 12: Preparation of N-ethyl-N'-(4-(2-(2-fluorophenoxy)acetyl)-2,5-dimethylphenyl )-N- methylformimidamide: Step-1: Preparation of N-(4-(2-chloroacetyl)-2,5-dimethylphenyl)acetamide: To a stirred mixture of N-(2,5-dimethylphenyl)acetamide (7.0 g, 42.9 mmol) and aluminium chloride (17.15 g, 129 mmol), chloroacetyl chloride (17.18 mL, 214 mmol) was added drop wise at 0 °C and the reaction mixture was stirred at 0 °C for 5 h. After completion of the reaction, the reaction mixture was quenched by addition of ice cold water (100 mL). The solid was filtered to obtain N-(4-(2-chloroacetyl)- 2,5-dimethylphenyl)acetamide (8.5 g, 35.5 mmol, 83 % yield). LCMS (M-1): 238.00 Step-2: Preparation of N-(4-(2-(2-fluorophenoxy)acetyl)-2,5-dimethylphenyl)acetamid e: To a stirred solution of N-(4-(2-chloroacetyl)-2,5-dimethylphenyl)acetamide (3.0 g, 12.52 mmol) in N,N-dimethylformamide (20 mL), potassium carbonate (3.46 g, 25.03 mmol) and 2-fluorophenol (1.54 g, 13.77 mmol) was added at 25 ℃. The reaction mixture was stirred at 25 ℃ for 6 h. After completion of the reaction, the reaction mixture was quenched by addition of water (100 mL). The solid was filtered to obtain N-(4-(2-(2-fluorophenoxy)acetyl)-2,5-dimethylphenyl)acetamid e (2.0 g, 6.34 mmol, 50.7 % yield). LCMS (M+1): 316 Step-3: Preparation of N-ethyl-N'-(4-(2-(2-fluorophenoxy)acetyl)-2,5-dimethylphenyl )-N- methylformimidamide: To a stirred solution of N-(4-(2-(2-fluorophenoxy)acetyl)-2,5-dimethylphenyl)acetamid e (2.5 g, 7.93 mmol) in toluene (20 mL), a mixture of phoshorousoxychloride (0.74 mL, 7.93 mmol) and N-ethyl-N- methylformamide (0.83 g, 9.51 mmol) in toluene (3 mL) was added at 25 ℃. The reaction mixture was stirred at 100 °C for 1 h. After completion of the reaction, the reaction mixture was quenched by addition of water (50 mL). Triethyl amine (5 mL) was added till the reaction mixture was neutralized, followed by extraction with ethyl acetate (100 mL x 2). The combined organic layers were dried over anhydrous sodium sulphate and concentrated under reduced pressure to obtain a crude product which was purified by preparative HPLC to obtain N-ethyl-N'-(4-(2-(2-fluorophenoxy)acetyl)-2,5-dimethylphenyl )-N- methylformimidamide (1.60 g, 4.67 mmol, 58.9 % yield). ¹ H-NMR (400 MHz, DMSO- d6) δ: 7.95-7.6 (m, 2H), 7.3-7.15 (m, 1H), 7.1-7.0 (m, 2H), 6.95-6.85 (m, 1H), 6.75-6.65 (m, 1H), 5.5 (s, 2H), 3.60- 3.31 (m, 2H), 3.12-3.9 (m, 3H), 2.4 (s, 3H), 2.35 (s, 3H) 1.15 (t, 3H); LCMS (M+1): 343.40 Example 13: Preparation of 3-methylbenzyl 5-chloro-4- (((ethyl(methyl)amino)methylene)amino)-2-methylbenzoate: To a stirred solution of 3-methylbenzyl 4-acetamido-5-chloro-2-methylbenzoate (0.7 g, 2.110 mmol) in toluene (10 mL), a mixture of phosphorousoxychloride (0.24 mL, 2.53 mmol) and N-ethyl-N- methylformamide (0.46 g, 5.27 mmol) in toluene (3 mL) was added at 25 °C. The reaction mixture was stirred at 90 °C for 1 h. After completion of the reaction, the reaction mixture was quenched by addition of water (50 mL) & triethylamine (1.5 mL) and extracted with ethyl acetate (2 x 50 mL), dried over anhydrous sodium sulphate and concentrated under reduced pressure to obtain a crude product which was purified by column chromatography on silica gel to obtain 3-methylbenzyl 5-chloro-4- (((ethyl(methyl)amino)methylene)amino)-2-methylbenzoate (0.64 g, 1.78 mmol, 85 % yield) as a brown viscous liquid. ¹ H-NMR (400 MHz, DMSO- d ₆ ) δ: 8.00 (s, 1H), 7.55 (bs, 1H), 7.28-7.22 (m, 2H), 7.16-7.14 (m, 1H), 6.70 (s, 1H), 5.26 (s, 2H), 3.51 (bs, 2H), 3.06 (bs, 3H), 2.55 (s, 3H), 2.37 (s, 3H), 1.26 (t, 3H); LCMS (M+1): 360.0 Example 14: Preparation of N-(2-bromobenzyl)-5-chloro-N-ethyl-4- (((ethyl(methyl)amino)methylene) amino)-2-methylbenzamide To a stirred solution of 4-acetamido-N-(2-bromobenzyl)-5-chloro-N-ethyl-2-methylbenza mide (0.7 g, 1.65 mmol) in toluene (7 mL), phosphorousoxychloride (0.19 mL, 1.98 mmol) and N-ethyl-N- methylformamide (0.22 g, 2.48 mmol) were added. The reaction mixture was stirred at 95 °C for 1 h. After completion of the reaction, the reaction mixture was cooled to 95 °C, quenched by addition of water (10 mL) and triethylamine (2 mL) and extracted with ethyl acetate (2 x 20 mL). The combined organic layers were washed with brine solution (20 mL), dried over anhydrous sodium sulphate and concentrated under reduced pressure to obtain a crude product which was purified by column chromatography on silica gel to obtain N-(2-bromobenzyl)-5-chloro-N-ethyl-4- (((ethyl(methyl)amino)methylene)amino)-2-methylbenzamide (0.58 g, 1.29 mmol, 78 % yield). ¹ H- NMR (400 MHz, DMSO- d ₆ )) δ 7.70 (s, 1H), 7.62-7.57 (m, 1H), 7.44-7.35 (m, 2H), 7.26-7.22 (m, 1H), 7.15 (s, 1H), 6.85 (s, 1H), 4.57 (d, J = 70.0 Hz, 2H), 3.39 (d, J = 6.4 Hz, 2H), 3.29-3.22 (m, 2H), 2.97 (s, 3H), 2.19 (s, 3H), 1.15 (t, J = 7.2 Hz, 3H), 1.12-0.94 (m, 3H). LCMS (M+1): 452.00. The following Table-I discloses representative examples of converting Z ^A to Z, but are not limited to the following examples: Table-I: