DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003

COMPLETE SPECIFICATION
(Section 10 and Rule 13)

A PROCESS FOR THE PREPARATION OF BELUMOSUDIL AND ITS INTERMEDIATES

AUROBINDO PHARMA LTD HAVING CORPORATE OFFICE AT
GALAXY, FLOORS: 22-24,
PLOT No.1, SURVEY No.83/1,
HYDERABAD KNOWLEDGE CITY,
RAIDURG PANMAKTHA,
RANGA REDDY DISTRICT,
HYDERABAD – 500 032,
TELANGANA, INDIA
AN INDIAN ORGANIZATION

The following specification particularly describes the invention and the manner in which it is to be performed:
FIELD OF THE INVENTION
The present invention relates to a process for the preparation of Belumosudil or pharmaceutically acceptable salts thereof. Further, the present invention provides a novel intermediate of Belumosudil and process for the preparation thereof.

BACKGROUND OF THE INVENTION
Belumosudil mesylate is a substituted quinazoline with 5-aminoindazole and a phenoxyacetamide component and is chemically known as 2-{3-[4-(1H-indazol-5-ylamino)-2-quinazolinyl]phenoxy}-N-(propan-2-yl)acetamide methanesulfonate (1:1). The chemical structure is as follows:

Belumosudil (REZUROCK®) is an inhibitor of Rho-associated coiled-coil kinase 2 (ROCK2) and indicated for the treatment of adult and pediatric patients 12 years and older with chronic graft-versus-host disease (chronic GVHD) after failure of at least two prior lines of systemic therapy.

US 8,357,693 describes Belumosudil or salt thereof and a general process for the preparation of Belumosudil, which involves multi-step process of about 10 steps.

CN 106916145 discloses a process for the preparation of Belumosudil, which involves additional tedious steps like ester formation and de-esterification in the preparation of compound of Formula-IV and also involves condensation and cyclization in two steps to obtain Belumosudil as shown in below scheme I:

Scheme I
WO 2023187697 discloses a process for the preparation of Belumosudil, which is similar to the process of CN 106916145.

The aforesaid prior art processes have difficulties with one or the other drawbacks such as multiple reaction steps, use of hazardous chemicals, column chromatography and/or low purity of intermediates and leads the process commercially not viable. Therefore, there is a need to develop an alternative process for the preparation of Belumosudil and its intermediates, which is simple, reduces number of steps, involves inexpensive raw materials and non-hazardous chemicals.

The inventors of present invention have found an alternative process for the preparation of Belumosudil as well as intermediates thereof, which involves use of a novel intermediate, single step for condensation and cyclization of Formula-IV and reduces number of steps than the prior art.

OBJECTIVE OF THE INVENTION
The objective of the present invention is to provide a process for the preparation of Belumosudil or pharmaceutically acceptable salts thereof from an intermediate of Formula-V:
.

In another objective of the present invention is to provide a novel intermediate of Formula-V and process for the preparation thereof.

SUMMARY OF THE INVENTION
In an aspect, the present invention provides a process for the preparation of Belumosudil of Formula-I or pharmaceutically acceptable salts thereof,

which comprises the steps of:
(a) reacting a compound of the Formula-V with 2-aminobenzamide of Formula-VI to obtain compound of Formula-IV;

(b) halogenating the compound of Formula-IV with a halogenating agent to obtain compound of Formula-II; and

wherein X is selected from fluoro, chloro, bromo and iodo.

(c) condensing the compound of Formula-II with 5-amino-1H-indazole to obtain Belumosudil or pharmaceutically acceptable salts thereof.

In another aspect, the present invention provides an intermediate of Formula-V or salts thereof:

In another aspect, the present invention provides a process for the preparation of intermediate of Formula-V, which comprises condensation of 3-hydroxybenzaldehyde of Formula-VII with 2-halo-N-isopropylacetamide of Formula-VIII to obtain compound of the Formula-V:

wherein X is selected from fluoro, chloro, bromo and iodo.

DETAILED DESCRIPTION OF THE INVENTION
The pharmaceutically acceptable salts or salts of the present invention comprises inorganic acid or organic acid. The inorganic acid is selected from hydrochloric acid, hydrobromic acid, sulfuric acid, sulfamic acid, phosphoric acid, and nitric acid; The organic acid is selected from acetic acid, propionic acid, succinic acid, glycolic acid, stearic acid, lactic acid, malic acid, tartaric acid, citric acid, ascorbic acid, palmitic acid, maleic acid, hydroxymaleic acid, phenylacetic acid, glutamic acid, benzoic acid, salicyclic acid, sulfanilic acid, 2-acetoxybenzoic acid, fumaric acid, toluenesulfonic acid, methanesulfonic acid, ethane sulfonic acid, and oxalic acid.

The intermediates and starting materials of the present invention are used as free base or salt thereof.

The suitable solvent comprises halogenated hydrocarbon, ketone, nitrile, hydrocarbon, alcohol, ether, ester, polar aprotic solvents, and water or the any combination thereof. The halogenated hydrocarbon solvent is selected from 1-bromopropane, dichloromethane, ethylene dichloride, chloroform, tetrachloroethylene, carbon tetrachloride, chlorobenzene, 1,2-dichlorobenzene and 1,2-difluorobenzene. The ketone solvent is selected from acetone, methyl isobutyl ketone, methyl ethyl ketone, mesityl oxide, isophorone, methyl isopropyl ketone, acetophenone, cyclopentanone, methyl sec-butyl ketone and pentanone. The nitrile solvent is selected from acetonitrile and benzonitrile. The hydrocarbon solvent is selected from hexane, heptane, cyclohexane, octane, pentane, isopentane, nonane, benzene, toluene, xylene and ethylbenzene. The alcohol solvent is selected from methanol, ethanol, tert-butanol, isopropanol, benzyl alcohol, 1,4-butanediol, tert-butyl alcohol, 2-ethylhexanol, isobutanol, 2-methyl-1-butanol, 2-pentanol, 1,3-propanediol and propylene glycol. The ether solvent is selected from methyl t-butyl ether, diethylether, tetrahydrofuran, 1,4-dioxane, dibenzyl ether, tert-amyl ethyl ether, cyclopentyl methyl ether, diisopropyl ether, dimethoxyethane, ethyl tert-butyl ether, 2-methyltetrahydrofuran, polyethylene glycol and tetrahydropyran. The ester solvent is selected from ethyl acetate, isopropyl acetate, benzyl benzoate, tert-butyl acetate, butyl acetate, diethyl carbonate, ethyl acetoacetate, ethyl butyrate, ethylene carbonate, hexyl acetate, isoamyl acetate, isobutyl acetate, methyl acetate, methyl propionate and propyl acetate. The polar aprotic solvents is selected from dimethylacetamide, formamide, acetamide, N-methylpyrrolidine (NMP), dimethyl formamide, n-methylformamide, 1,3-dimethyl-2-imidazolidinone, n-formylmorpholine, 2-pyrrolidone, tetramethylurea, n-vinylpyrrolidone and n-vinylacetamide and dimethyl sulfoxide.

In an aspect, the present invention provides a process for the preparation of Belumosudil, a compound of Formula-I or pharmaceutically acceptable salts thereof,

which comprises the steps of:
(a) reacting a compound of the Formula-V with 2-aminobenzamide of Formula-VI to obtain compound of Formula-IV;

(b) halogenating the compound of Formula-IV with a halogenating agent to obtain compound of Formula-II; and

wherein X is selected from fluoro, chloro, bromo and iodo

(c) condensing the compound of Formula-II with 5-amino-1H-indazole to obtain Belumosudil or pharmaceutically acceptable salts thereof.

The addition of 2-aminobenzamide in step a) is performed in lot-wise addition or direct charging to enhance the reaction completion while controlling contamination of impurities.

The process of step a) i.e. condensation and cyclization is carried out in the presence or absence of a reagent and solvent to obtain compound of Formula-IV.

The suitable reagent comprises sodium metabisulfite, sodium bisulfite, zinc chloride, copper chloride, iron chloride, lanthanum chloride, gadolinium chloride, yttrium chloride, scandium chloride, sodium dithionite, gallium trifluoromethanesulfonate, vanadyl acetylacetonate, vanadium oxide and vanadyl sulfate or combination thereof. In an embodiment, the suitable reagent comprises sodium metabisulfite and sodium bisulfite.

The suitable solvent comprises polar aprotic solvents such as formamide, acetamide, dimethyl formamide, dimethylacetamide, NMP, dimethyl sulfoxide and the like; hydrocarbon solvent; halogenated hydrocarbon solvent; nitrile or combination thereof. This step is carried out at a temperature of about 0 °C to about 200 °C or to reflux based on the solvent used. In an embodiment, the reaction is carried out at about 100 to 130 °C for a period of about 1 hour to about 20 hours or until the completion of the reaction.

The resultant compound of Formula IV is further purified by using purification techniques such as recrystallization, anti-solvent technique, and/or crash cooling. The solvent used for the purification comprises halogenated hydrocarbon solvent, alcohol, hydrocarbon, ester, ether, water, or combination thereof.

The suitable halogenating reagent in step b) comprises chlorinating agent, brominating agents, fluorination reagents, or iodination reagents. The chlorinating agent is selected from thionyl chloride, phosphrous oxychloride, phosphorus trichloride, phosphorus pentachloride, oxalyl chloride, calcium hypochlorite or combination thereof. The brominating agent is selected from phosphorus oxybromide, phosphorus tribromide, bromine chloride, and aluminum tribromide or combination thereof; The fluorination reagent is selected from phosphorus trifluoride, phosphorus pentafluoride or combination thereof; The iodination reagent is selected from phosphorus triiodide and phosphorus pentaiodide or combination thereof. In an embodiment, the suitable reagent comprises chlorinating agent.

The process of step b) is carried out in presence of a suitable base and solvent to obtain compound of Formula-II.

The suitable base in step b) comprises diisopropylethylamine, triethylamine, diisopropylamine, diethylamine, piperidine, pyridine N-methyl morpholine (NMM), N,N-dimethylbenzylamine, picoline, lutidine, N,N-dimethylaniline, tert.butyl amine, 4-dimethylaminopyridine (DMAP), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) and 1,4-diazabicyclo[2.2.2]octane (DABCO) or mixture of thereof. In an embodiment, the suitable base comprises diisopropylethylamine, triethylamine, diisopropylamine and diethylamine.

The suitable solvent in step b) comprises hydrocarbon, halogenated hydrocarbon, polar aprotic solvent and N-methylformamide or combination thereof. This process step is carried out at a temperature of about 0 to about 150 °C or at a higher temperature based on the solvent used. The reaction is conducted for a period of about 1 hour to about 15 hours or until the completion of the reaction. The resultant compound of Formula-II is used for the next step without isolation.

The process of step c) involves reaction of compound of Formula-II with 5-amino-1H-indazole of the Formula-III in presence of solvent and suitable base to obtain Belumosudil or salt thereof.

The suitable base in step c) comprises carbonate of lithium, sodium, potassium, barium, calcium, magnesium; bicarbonate of sodium, potassium, barium, calcium and magnesium; hydroxides of alkali metals like sodium, potassium, lithium, barium, calcium, cesium, strontium and magnesium, alkoxide of metal like sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide or mixture of thereof.

The suitable solvent in step c) comprises alcohol, hydrocarbon solvent, polar aprotic solvents, ether solvent, nitrile solvent, ketone solvent or combination thereof.

This process is conducted at a temperature of about 0 to about 150 °C or at a higher temperature based on the solvent used, for a period of about 1 hour to about 15 hours or until the completion of the reaction.

The obtained Belumosudil is optionally purified by recrystallization or slurry in a solvent like water, alcohol, or combination thereof. Further, the salt of Belumosudil is obtained by treating it with an acid in the presence of suitable solvent. The suitable solvent comprises alcohol, hydrocarbon solvent, polar aprotic solvent, ether solvent, nitrile solvent, ketone solvent, or combination thereof.

In another aspect, the present invention provides a process for the preparation of intermediate of Formula-V, which comprises condensation of 3-hydroxybenzaldehyde of Formula-VII with 2-halo-N-isopropylacetamide of Formula-VIII to obtain compound of the Formula-V:
wherein X is selected from fluoro, chloro, bromo and iodo

The reaction of 3-hydroxybenzaldehyde of Formula-VII with 2-halo-N-isopropylacetamide of Formula-VIII is conducted in presence or absence of a suitable base and solvent to obtain compound of Formula-V.

The suitable base comprises an inorganic base, which is selected from carbonate of lithium, sodium, potassium, barium, calcium, magnesium; bicarbonate of sodium, potassium, barium, calcium and magnesium; hydroxides of alkali metals like sodium, potassium, lithium, barium, calcium, cesium, strontium and magnesium; oxides of metal like potassium, sodium, calcium, lithium, zinc, iron, cobalt, chrome, copper, manganese and nickel; alkoxide of metal like sodium methoxide, sodium ethoxide, potassium methoxide and potassium ethoxide or mixture of thereof.

The suitable solvent in the above reaction comprises polar aprotic solvent, nitrile solvent, hydrocarbon, ketone solvent, alcohol, halogenated hydrocarbon solvent or combination thereof.

In another aspect, the present invention provides Belumosudil intermediate of Formula-V or salts thereof:

The compound of the Formula-V is used in the preparation of Belumosudil or pharmaceutically acceptable salts thereof.

In one embodiment, present invention provides Belumosudil or pharmaceutically acceptable salts thereof, which is substantially free of impurities represented by the following compounds of Formula II to V and IX to XII:

The impurities set forth above are identified by standard analytical techniques known to a person of skill in the art such as High-Performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS).

As used herein, the term "substantially free of impurities", refers to the Belumosudil or pharmaceutically acceptable salts thereof obtained by the process of the present invention having less than from about 0.15% w/w to about 0.05% w/w (as determined by HPLC) of the above specified impurities.

The starting materials used in this aspect, 3-hydroxy benzaldehyde (VII), 2-halo-N-isopropylacetamide (VIII), 2-aminobenzamide (VI) and 5-amino indazole (III) are obtained according to any method known in the art, for example, Journal of Organic Syntheses, 29, 63, 1949, Journal of Organic Chemistry (1948), 13, 347-52, Journal of the American Chemical Society, 1943, 65, 10, 1804–1806 and Canadian Journal of Chemistry (1979), 57(15), 1958-66.

The following examples illustrate the nature of the invention and are provided for illustrative purposes only and should not be construed to limit the scope of the invention.

EXAMPLES

Example 1: Preparation of 2-Chloro-N-isopropylacetamide (VIII):
Isopropylamine (209.4g) was dissolved in methylene chloride (600 ml) at 20-30 °C and cooled the reaction mass to -15 to 0°C. Thereafter, a solution of chloroacetyl chloride (200g) in methylene chloride (200ml) was added slowly to reaction mass at -15 to 0°C. The reaction mass was stirred at -15 to 0°C for 1h and filtered and then washed with methylene chloride (600ml). The aqueous sodium chloride solution (400 ml; 10%w/w) was added to the reaction mass and separated the layers. The organic layer was concentrated at a temperature below 50°C under atmospheric pressure.

Example 2: Preparation of 2-(3-formylphenoxy)-N-isopropylacetamide (V):
The concentrated mass obtained in example 1 was added to N,N-dimethylformamide (600ml) at temperature below 50°C and then concentrated under reduced pressure. The reaction mass was cooled to 20-30°C. Thereafter, 3-hydroxybenzaldehyde (VII) (205.44g) and subsequently potassium carbonate (244.75g) were added to the concentrated mass and raised the temperature to 65-70°C. The reaction mass was stirred at 60-70°C for 12 h and cooled to 45-50°C. The purified water (?3000ml) was added slowly at maintaining temperature of about 45-50°C, cooled to 20-30°C and stirred for 30±5 min. Thereafter, the product slurry was cooled to 2-8°C and stirred for 30±5. The obtained product was filtered at 2-8°C and washed with pre-cooled purified water (600ml) followed by with methyl tertiary-butyl ether (200ml) at 5-15°C. The wet filtered mass (?426g) was dried under the reduced pressure for 2h±15 min without applying heating, thereafter, continued drying at 40-50°C to obtain 2-(3-formylphenoxy)-N-isopropylacetamide (V) (Yield: 300g, 76.5%, Purity by HPLC: 99.85%, 1H NMR (300 MHz, CDCl3)d (ppm): 9.99 (s, 1H), 7.50-7.43 (m, 3H), 7.23-7.19(m,1H), 6.25 (br, NH, 1H), 4.51(s, 2H), 4.21-4.19(m, 1H),1.21(d, J=6.6Hz, 6H).

Example 3: Purification of 2-(3-formylphenoxy)-N-isopropylacetamide (V):
The obtained wet filtered mass (?426g) in example 2 was suspended in methyl tertiary butyl ether (1800ml), heated to 50-55°C and stirred for 30±5 min. Thereafter, the mass was cooled to 2-8°C and stirred for 30±5 min. The obtained product was filtered at 2-8°C and washed with pre-cooled methyl tertiary butyl ether (400ml). The wet filtered mass (?420g) was dried under the reduced pressure for 2h±15 min without applying heating, thereafter, continued drying at 40-50°C to obtain 2-(3-formylphenoxy)-N-isopropylacetamide (V) (Yield: 255g, 65%, Purity by HPLC: 99.95%).

Example 4: Preparation of 2-(3-quinazolin-4(3H)-one)phenoxy)-N-isopropylacetamide (IV):
2-(3-formylphenoxy)-N-isopropylacetamide (V) (230g) was added to 2-aminobenzamide (VI) (148.60g), and subsequently sodium metabisulfite (148.2 g) and N,N’-dimethylacetamide (1380ml) were added at 20-30°C. Thereafter, raised the temperature of reaction mass to 115-125°C. The reaction mass was stirred till the completion of the compound of Formula V, cooled the reaction mass to 20-30°C. The purified water (2760ml) was slowly added to the reaction mass at a temperature below 40°C and stirred at 20-30°C for 30±5 min. The obtained solid was filtered and washed with purified water (2x345ml) and methylene chloride (2x230ml). The resultant filtered mas was dried under reduced pressure for 2h±15min without applying heating and then dried at 50-60°C to obtain 2-(3-quinazolin-4(3H)-one)phenoxy)-N-isopropylacetamide (IV) (Yield: 306g, 92.1%, Purity by HPLC: 99.91%).

Example 5: Purification of 2-(3-quinazolin-4(3H)-one)phenoxy)-N-isopropylacetamide (IV):
2-(3-quinazolin-4(3H)-one)phenoxy)-N-isopropylacetamide (IV) (?425g) obtained in example 4 was suspended in methylene chloride (1380ml) at 20-30°C and heat the reaction mass to reflux at 35-40°C. The reaction mass was stirred for 30±5 min at 20-30°C. The obtained mass was filtered and washed with methylene chloride (2x230ml) at 20-30°C. The wet filtered mass was dried under reduced pressure for 2h±15min without heating and then dried at 50-60°C under reduced pressure to obtain 2-(3-quinazolin-4(3H)-one)phenoxy)-N-isopropylacetamide (IV) (Yield: 285g, 81.5%, Purity by HPLC: 99.95%).

Example 6: Preparation of 2-(3-(4-chloroquinazolin-2-yl)phenoxy)-N-isopropylacetamide (II):
2-(3-quinazolin-4(3H)-one)phenoxy)-N-isopropylacetamide (IV) (200g) was dissolved in toluene (3000ml) and cooled the reaction mass to 5-15°C. Diisopropylethylamine (115g) and subsequently phosphorus oxychloride (127.3g) were added slowly to reaction mass at 5-15°C. The reaction mass was stirred for 30±5 at 5-15°C and raised the temperature of the reaction to 75-85°C. The reaction mass was stirred at 75-85°C and cooled to 25-30°C. Methylene chloride (2000ml) and purified water (1000ml) were added and then allowed the layers to settle and separated the layers. Toluene (335ml)-methylene chloride (65ml) solvent mixture (400ml) was added to aqueous layer. The layers were allowed to settle and separated. The 5%w/w aqueous sodium bicarbonate solution (900m) was added to obtained organic layer, and then the layers were separated. The obtained organic layer (?5200ml) was filtered and washed with methylene chloride (50ml) (Purity by HPLC: 97.28%).

Example 7: Preparation of Belumosudil (I):
The organic layer obtained in example 6 was concentrated at below 50°C under reduced pressure and cooled to 20-25°C. Sodium bicarbonate (54.77g) and followed by ethanol (600ml) were added to the reaction mass at 20-25°C. Thereafter, 5-aminoindazole (III) solution in ethanol (?1400ml; by dissolving 77.35g of 5-aminoindazole in 1300ml of ethanol) at 20-25°C was added to reaction mass and raised the temperature to 70-80°C and then stirred at 70-80°C for 3hours. The reaction mass was cooled to 20-30°C and stirred for 30±5 min. The reaction mass was filtered and washed with ethanol (400ml). The obtained wet product was added to purified water (2000ml) and stirred for 30±5 min. The obtained product was filtered and washed with purified water (2x300ml) and then with ethanol (2x300ml). The obtained wet filtered mass (?370g) was dried under reduced pressure for 2h±15 min without applying heating. Thereafter, the solid was dried at 50-60°C for 6h under reduced pressure to obtain Belumosudil (Yield: 200g, 74.55%, Purity by HPLC: 99.91%).

Example 8: Purification of Belumosudil base:
Ethanol (1600ml) was added to the belumosudil base (?370g), heated the reaction mass to 70-80°C, stirred for 1h±10 min and then cooled to 10-15°C. The reaction mass was filtered and washed with pre-cooled ethanol (400ml). The purified water (2000ml) was added to the wet Belumosudil and stirred for 30±5 at 20-30 °C min. The resultant reaction mass was filtered and washed with purified water (2x300ml). The filtered mass was washed with ethanol (2x300ml) at 20-30°C and dried under reduced pressure for 2h±15 min without applying heating. Thereafter, the solid was dried at 50-60°C for 6h under reduced pressure to obtain Belumosudil base (Yield: 190g, 70.82%, Purity by HPLC: 99.91%)

Example 9: Preparation of Belumosudil mesylate:
Belumosudil base (100 g) was suspended in ethanol (3000 ml) and heated the reaction mixture to 70-75°C. The methanesulfonic acid (25.50g) solution in ethanol (2000ml) was added slowly to the reaction mass for 5h. Thereafter, stirred the reaction mass for 1h±10 min, cooled to 20-30°C and then stirred for 1h±15 min. The obtained mass was filtered at 20-30°C and washed with ethanol (2x200 ml). The wet filtered mass was dried under reduced pressure for 2h±15min without applying heating. Thereafter, the solid was dried at 50-60°C under reduced pressure to obtain Belumosudil mesylate (Yield: 110g, 90.80%, Purity by HPLC: 99.97%).
Impurity Formula IV: 0.02%,
Impurity Formula II: 0.01%
Impurity Formula III, Impurity Formula V, Impurity Formula IX, Impurity Formula X, Impurity Formula XI and Impurity Formula XII: Not detected ,CLAIMS:WE CLAIM:

1. A process for the preparation of Belumosudil of Formula (I), or a pharmaceutically acceptable salt thereof:

which comprises the steps of:
(a) reacting a compound of the Formula-V with 2-aminobenzamide of Formula-VI to obtain compound of Formula-IV;

(b) reacting the compound of Formula-IV with a halogenating agent to obtain compound of Formula-II; and

wherein X is selected from fluoro, chloro, bromo and iodo.

(c) condensing the compound of Formula-II with 5-amino-1H-indazole to obtain Belumosudil or salt thereof.

2. The process as claimed in claim 1, wherein the step a) is carried out in presence of suitable reagent such as sodium metabisulfite and sodium bisulfite.

3. The process as claimed in claim 1, wherein the halogenating agent is chlorinating agent.

4. The process as claimed in claim 1, wherein the suitable solvent is selected from the group comprising polar aprotic solvents, hydrocarbon solvent, halogenated hydrocarbon, nitrile solvent, alcohol, ether solvent, ketone solvent or the any combination thereof.

5. The process as claimed in claim 1, wherein the steps b) and c) are carried out in presence of base.

6. The process as claimed in claim 1, wherein the Belumosudil or pharmaceutically acceptable salts thereof is substantially free of at least one of impurities of formulae IX to XII:

7. A process for the preparation of Belumosudil intermediate of Formula-V, which comprises condensation of 3-hydroxybenzaldehyde of Formula-VII with 2-halo-N-isopropylacetamide of Formula-VIII:

wherein X is selected from fluoro, chloro, bromo and iodo.

8. The process as claimed in claim 7, wherein the condensation is carried out in presence of inorganic base.

9. The process as claimed in claim 7, wherein suitable solvent is selected from the group comprising dimethyl acetamide, dimethylformamide, acetonitrile, benzonitrile, toluene, acetone, N-methyl-2-pyrrolidone, methanol, ethanol, dimethyl sulfoxide, toluene, dichloromethane or mixture of thereof or the any combination thereof.

10. The compound of Formula