FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
"PROCESS FOR THE PREPARATION OF MARAVIROC"
AJANTA PHARMA LTD.
A company incorporated under the laws of India having their office at
98, Ajanta house, Charkop, Kandivli (West)
Mumbai - 400067, Maharashtra, India.
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 4,4-difluoro-N-{(lS)-3-[3-(3-isopropyl-5-methyl-4H-l ,2,4-triazol-4-yl)-8-azabicyclo[3.2.1 ]oct-8-yl]-l -phenylpropyl}cyclo hexanecarboxamide represented by Formula I, commonly known as Maraviroc.
The process provides Maraviroc in higher yield and purity compared to the previously known processes.
BACKGROUND OF THE INVENTION
Maraviroc is an antiretroviral drug in the CCR5 (C-C chemokine receptor type 5) receptor antagonist class used in the treatment of HIV infection.
Maraviroc and various processes for preparation of Maraviroc were disclosed in U.S. Patent No. 6,667,314. One of the process as described in the patent is depicted as follows in scheme I.

U.S. Patent No. 6,667,314, discloses the preparation of Maraviroc, wherein 3-(3-Isopropyl-5-methyl-4H-l, 2, 4-triazol-4-yl)-exo-8-azabicyclo [3.2.1] octane is reacted with sodium triacetoxyborohydride in presence of acetic acid to give Maraviroc.
Indian patent application 1840/MUM/2012, discloses the preparation of Maraviroc by reductive amination using ammonium salt as a reducing agent, as shown below,
Chinese patent application CN104860946, discloses the process for preparation of intermediate used for preparation of Maraviroc i.e. compound of Formula 1 obtained via reductive amination reaction, as shown below,
Organic Process Research & Development 2008, 12, 1104-1113 discloses process for preparation of Maraviroc by six-step synthetic route as shown below,

The process for preparation of Maraviroc described in the above patents or patent applications suffer from the drawbacks like low purity levels of Maraviroc and/or intermediates thereof and use of moisture sensitive and hazardous compounds like acid chloride.
Overall, the processes for preparation of Maraviroc and its intermediates described in above prior arts are not suitable for large scale production due to drawbacks discussed above. Therefore, there is a need for a simple, efficient and commercially viable process for preparation of Maraviroc and/or intermediates thereof with higher purity levels.
The present invention provides such an improved process for the preparation of Maraviroc and/or intermediates thereof, avoiding the above drawbacks.
SUMMARY OF THE INVENTION
According to an aspect of the present invention, there is provided a process for preparation of Maraviroc of Formula I, comprising

reacting a compound of Formula II
with a compound of Formula III
According to another aspect of the present invention, there is provided an improved process for preparation of Maraviroc of Formula I comprising steps of,
(lS)-4,4-difluoro-N-(3-oxo-l-phenylpropyl)cyclohexane carboxamide of Formula III and 3-(3-isopropyl-5-methyl-4H-l,2,4-tiazol-4-yl)-exo-8-azabicyclo [3.2.1] octane phosphate salt of Formula II is reacted with sodium triacetoxyborohydride and isolation using acid base work up to get Maraviroc of Formula I.
Another object of the present invention is to provide an improved process for preparation of the Maraviroc intermediate represented by a compound of Formula III from compound of Formula VII, while compound of Formula VII is obtained from 4,4-difluoro cyclohexane carboxylic acid of Formula V, (S)-3-Amino-3-phenyl propan-1-ol of Formula VI, with higher purity levels.

Another object of the present invention is to provide an improved process for preparation of the Maraviroc intermediate represented by a compound of Formula II while avoiding instability amino characteristic towards air oxidation and to get ultra-pure intermediate of Formula II.
Another object of the present invention is to provide an improved process for preparation of highly purified Maraviroc while avoiding the use of moisture sensitive acid chloride compound and use of hazardous thionyl chloride.
Another object of the present invention is to provide an improved process for preparation of highly purified Maraviroc while removing impurity by acid-base purification to avoid yield loss during purification by crystallization.
DETAILED DESCRIPTION OF INVENTION
The present invention relates to the improved, simple and economic process for the preparation of Maraviroc of Formula I
The process of the present invention for preparation of Maraviroc of Formula I is as depicted
below,
STAGE 1;
Preparation of (lS)-4, 4-Difluoro-N-(3-hydroxy-l-phenylpropyl) cyclohexane carboxamide of Formula VII

Process-1:
4,4-Difluoro cyclohexane carboxylic acid of Formula V is reacted with (S)-3-amino-3 -phenyl propan-1-ol of Formula VI in presence of 1-Hydroxybenzotriazole hydrate (HOBT), 1,3-dicyclohexyldiimide (DCC) and organic solvent to get (lS)-4,4-difluoro-N-(3 -hydroxy-1-phenylpropyl) cyclohexane carboxamide of Formula VII.
In one embodiment, reaction between Formula V & Formula VI may be performed in the presence of a suitable base and a suitable solvent.
In one embodiment, the reaction may be carried out at a temperature of about 20°C to about 40°C optionally, under stirring. Preferably the reaction may be carried out at a temperature of about 20°C to about 30°C, more preferably at about 25°C to about 30°C.
In one embodiment, the reaction may be performed in the presence of a suitable base which may include organic and inorganic bases.
In one embodiment, an organic base used, includes, but is not limited to, primary, secondary or tertiary amines such as methylamine, n-methyl morpholine, ethylamine, n-propylamine, isopropylamine, triethylamine, N,N-diisopropylethylamine and the like.
In one embodiment, inorganic base used, includes, but is not limited to, alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, lithium hydroxide and the like; alkaline earth metal carbonates; alkali metal carbonates such as sodium carbonate, caesium carbonate, potassium carbonate and the like; alkali metal bicarbonates such as sodium bicarbonate, potassium bicarbonate and the like.
In one embodiment, the suitable solvent used, includes, but is not limited to alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol and the like;

haloalkanes such as dichloromethane, chloroform and the like; ethers such as dimethyl ether, diethyl ether, diisopropyl ether, tert-butyl methyl ether, tetrahydrofuran, dioxane and the like; esters such as methyl acetate, ethyl acetate, n-propyl acetate, tert-butyl acetate and the like; hydrocarbons such as toluene, xylene and the like; dimethyl sulfoxide; dimethyl formamide; dimethyl acetamide; N-Methyl-2-pyrrolidone; water; or mixtures thereof. Preferably the solvent selected a haloalkane, more preferably dichloromethane.
In one embodiment, after completion of the reaction, suitable work up may be performed, as known to a skilled artisan, to isolate the compound of Formula VII before purification. In one embodiment, water may be added to the reaction mixture after completion of the reaction and organic solvent layer, preferably dichloromethane layer may be separated and washed with water and dried. The product may be isolated by distillation of the solvent to get residue which may be further purified.
In one embodiment, the product obtained may be purified by techniques known in the art such as crystallization, fractional crystallization, liquid-liquid extraction and the like.
In one embodiment, the improved process for preparation of compound of Formula VII avoids the use of moisture sensitive acid chloride compound and use of hazardous thionyl chloride.
4,4-difluoro cyclohexane carboxylic acid of Formula V is converted to mix anhydride with ethyl chloroformate further react with (S)-3-amino-3-phenyl propan-1-ol of Formula VI in an

organic solvent to get (lS)-4,4-difluoro-N-(3-hydroxy-1-phenylpropyl) cyclohexane carboxamide of Formula VII.
In one embodiment, the reaction may be performed in the presence of a suitable base and a suitable solvent.
In one embodiment, the reaction may be carried out at a temperature of about 0°C to about 15°C optionally, under stirring. Preferably the reaction may be carried out at a temperature of about 0°C to about 10°C, more preferably at about 0°C to about 5°C.
In one embodiment, the reaction may be performed in the presence of a suitable base which may include organic and inorganic bases.
In one embodiment, an organic base used includes, but is not limited to, primary, secondary or tertiary amines such as methylamine, n-methyl morpholine, ethylamine, n-propylamine, isopropylamine, triethylamine, N,N-diisopropylethylamine and the like. Preferably the organic base selected is triethylamine.
In one embodiment, inorganic base used, includes, but is not limited to, alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, lithium hydroxide and the like; alkaline earth metal carbonates; alkali metal carbonates such as sodium carbonate, caesium carbonate, potassium carbonate and the like; alkali metal bicarbonates such as sodium bicarbonate, potassium bicarbonate and the like.
In one embodiment, the suitable solvent used includes, but is not limited to alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol and the like; haloalkanes such as dichloromethane, chloroform and the like; ethers such as dimethyl ether, diethyl ether, diisopropyl ether, tert-butyl methyl ether, tetrahydrofuran, dioxane and the like; esters such as methyl acetate, ethyl acetate, n-propyl acetate, tert-butyl acetate and the like; hydrocarbons such as toluene, xylene and the like; dimethyl sulfoxide; dimethyl formamide; dimethyl acetamide; N-methyl-2-pyrrolidone; water; or mixtures thereof. Preferably the solvent selected is ethyl acetate.
In one embodiment, after completion of the reaction, suitable work up may be performed, as known to a skilled artisan, to isolate the compound of Formula VII before purification. In one embodiment, water may be added to the reaction mixture after completion of the reaction and

organic solvent layer, preferably organic layer, was separated and washed with water and dried. The product may be isolated by distillation of the solvent to get residue which may be further purified.
In one embodiment, the product obtained may be purified by techniques known in the art such as crystallization, fractional crystallization, liquid-liquid extraction and the like.
In one embodiment, the improved process for preparation of compound of Formula VII avoids the use of moisture sensitive acid chloride compound and use of hazardous thionyl chloride.
Stage 2:
Preparation of (lS)-4,4-difluoro-N-(3-oxo-1-phenylpropyl) cyclohexane carboxamide of Formula III
(lS)-4,4-difluoro-N-(3-hydroxy-1-phenylpropyl) cyclohexane carboxamide of Formula VII is converted to (lS)-4,4-difluoro-N-(3-oxo-1-phenylpropyl) cyclohexane carboxamide of Formula III by using potassium bromide, (2,2,6,6-Tetramethylpiperidin-l-yl)oxyl (TEMPO), sodium thiosulphate and sodium hypochlorite.
In one embodiment, the reaction may be performed in the presence of a suitable base and a suitable solvent.
In one embodiment, the reaction may be carried out at a temperature of about 15°C to about 40°C optionally, under stirring. Preferably the reaction may be carried out at a temperature of about 20°C to about 35°C, more preferably at about 25°C to about 30°C.

In one embodiment, the reaction may be performed in the presence of a suitable base which may include organic and inorganic bases.
In one embodiment, an organic base used includes, but is not limited to, primary, secondary or tertiary amines such as methylamine, n-methyl morpholine, ethylamine, n-propylamine, isopropylamine, triethylamine, N,N-diisopropylethylamine and the like.
In one embodiment, inorganic base used, includes, but is not limited to, alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, lithium hydroxide and the like; alkaline earth metal carbonates; alkali metal carbonates such as sodium carbonate, caesium carbonate, potassium carbonate and the like; alkali metal bicarbonates such as sodium bicarbonate, potassium bicarbonate and the like.
In one embodiment, the suitable solvent used, includes, but is not limited to alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol and the like; haloalkanes such as dichloromethane, chloroform and the like; ethers such as dimethyl ether, diethyl ether, diisopropyl ether, tert-butyl methyl ether, tetrahydrofuran, dioxane and the like; esters such as methyl acetate, ethyl acetate, n-propyl acetate, tert-butyl acetate and the like; hydrocarbons such as toluene, xylene and the like; dimethyl sulfoxide; dimethyl formamide; dimethyl acetamide; N-Methyl-2-pyrrolidone; water; or mixtures thereof. Preferably the solvent selected is ethyl acetate.
In one embodiment, after completion of the reaction, suitable work up may be performed, as known to a skilled artisan, to isolate the compound of Formula III before purification. In one embodiment, water may be added to the reaction mixture after completion of the reaction and organic solvent layer, preferably organic layer may be separated and washed with water and dried. The product may be isolated by distillation of the solvent to get residue which may be further purified.
In one embodiment, the product obtained may be purified by techniques known in the art such as crystallization, fractional crystallization, liquid-liquid extraction and the like.
In one embodiment, the improved process for preparation of compound of Formula III gives higher yield while using minimum reagent.

Stage 3:
Preparation of Maraviroc crude:
According to another aspect of the present invention, there is provided an improved process for preparation of Maraviroc of Formula I comprising,
(lS)-4,4-difluoro-N-(3-oxo-l-phenylpropyl)cyclohexane carboxamide of Formula III and 3-(3-isopropyl-5-methyl-4H-l,2,4-tiazol-4-yl)-exo-8-azabicyclo [3.2.1] octane phosphate salt of Formula II is reacted with sodium triacetoxyborohydride and isolation using acid base work up to get Maraviroc of Formula I.
In one embodiment, the reaction may be performed in the presence of a suitable base and a suitable solvent.
In one embodiment, the reaction may be carried out at a temperature of about 15°C to about 40°C optionally, under stirring. Preferably the reaction may be carried out at a temperature of about 20°C to about 35°C, more preferably at about 25°C to about 30°C.
In one embodiment, the reaction may be performed in the presence of a suitable base which may include organic and inorganic bases. In one embodiment, the reaction may be performed in the nitrogen atmosphere.
In one embodiment, an organic base used includes, but is not limited to, primary, secondary or tertiary amines such as methylamine, n-methyl morpholine, ethylamine, n-propylamine, isopropylamine, triethylamine, N,N-diisopropylethylamine and the like.

In one embodiment, inorganic base used, includes, but is not limited to, alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, lithium hydroxide and the like; alkaline earth metal carbonates; alkali metal carbonates such as sodium carbonate, caesium carbonate, potassium carbonate and the like; alkali metal bicarbonates such as sodium bicarbonate, potassium bicarbonate and the like.
In one embodiment, the suitable solvent used includes, but is not limited to alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol and the like; haloalkanes such as dichloromethane, chloroform and the like; ethers such as dimethyl ether, diethyl ether, diisopropyl ether, tert-butyl methyl ether, tetrahydrofuran, dioxane and the like; esters such as methyl acetate, ethyl acetate, n-propyl acetate, tert-butyl acetate and the like; hydrocarbons such as toluene, xylene and the like; dimethyl sulfoxide; dimethyl formamide; dimethyl acetamide; N-methyl-2-pyrrolidone; water; or mixtures thereof. Preferably the solvent selected is ethyl acetate.
In one embodiment, after completion of the reaction, suitable work up may be performed, as known to a skilled artisan, to isolate the compound of Formula I before purification. In one embodiment, water may be added to the reaction mixture after completion of the reaction and organic solvent layer, preferably organic layer may be separated and washed with water and dried. The product may be isolated by distillation of the solvent to get residue which may be further purified.
In one embodiment, the product obtained may be purified by techniques known in the art such as crystallization, fractional crystallization, liquid-liquid extraction and the like.
In one embodiment, the impurity may be removed by acid-base purification to avoid the yield loss during purification by crystallization.
In one embodiment, the impurity is controlled during reaction by using phosphate salt of triazole compound of Formula II without using acetic acid and acid-base work up to get ICH quality Maraviroc compound.

Preperation of Intermediate Triazole:
Preparation of 3-(3-isopropyl-5-methyl-4H-l,2,4-triazol-4-yl)-exo-8-azbicyclo [3.2.1] octane phosphate salt
In another embodiment, 8-benzyl-3-(3-isopropyl-5-methyl-4H-l,2,4-triazol-4-yl)-8-aza-bicyclo [3.2.1] octane of Formula IX is reacted with ammonium formate, palladium carbon, ammonia and organic solvent. Reaction mass filtered and solvent is removed completely. Residue crystallized with ethyl acetate and reacts with o-phosphoric acid in organic solvent to get 3-(3-Isopropyl-5-methyl-4H-l,2,4-triazol-4-yl)-exo-8-azabicyclo [3.2.1] octane phosphate salt of Formula II.
In one embodiment, the reaction may be performed in the presence of a suitable base and a suitable solvent.
In one embodiment, the reaction may be carried out at a temperature of about 15°C to about 40°C optionally, under stirring. Preferably the reaction may be carried out at a temperature of about 20°C to about 35°C, more preferably at about 25°C to about 30°C.
In one embodiment, the reaction may be performed in the presence of a suitable base which may include organic and inorganic bases. In one embodiment, the reaction may be performed in the nitrogen atmosphere.

In one embodiment, an organic base used includes, but is not limited to, primary, secondary or tertiary amines such as methylamine, n-methyl morpholine, ethylamine, n-propylamine, isopropylamine, triethylamine, N,N-diisopropylethylamine and the like.
In one embodiment, inorganic base used, includes, but is not limited to, alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, lithium hydroxide and the like; alkaline earth metal carbonates; alkali metal carbonates such as sodium carbonate, caesium carbonate, potassium carbonate and the like; alkali metal bicarbonates such as sodium bicarbonate, potassium bicarbonate and the like.
In one embodiment, the suitable solvent used, includes, but is not limited to alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol and the like; haloalkanes such as dichloromethane, chloroform and the like; ethers such as dimethyl ether, diethyl ether, diisopropyl ether, tert-butyl methyl ether, tetrahydrofuran, dioxane and the like; esters such as methyl acetate, ethyl acetate, n-propyl acetate, tert-butyl acetate and the like; hydrocarbons such as toluene, xylene and the like; dimethyl sulfoxide; dimethyl formamide; dimethyl acetamide; N-methyl-2-pyrrolidone; water; or mixtures thereof. Preferably the solvent selected is ethyl acetate.
In one embodiment, after completion of the reaction, suitable work up may be performed, as known to a skilled artisan, to isolate the compound of Formula II before purification. In one embodiment, water may be added to the reaction mixture after completion of the reaction and organic solvent layer, preferably organic layer is separated and washed with water and dried. The product may be isolated by distillation of the solvent to get residue which may be further purified.
In one embodiment, the product obtained may be purified by techniques known in the art such as crystallization, fractional crystallization, liquid-liquid extraction and the like.
In one embodiment, phosphate salt preparation avoids instability amino characteristic towards air oxidation and is easy to purify and get ultra-pure intermediate of Formula II.
In one embodiment, the process of purification of Maraviroc may be carried out using process known in the art, if required.

The present invention is explained in detail by referring to examples, which are not to be construed as limitative.
Example-1: Preparation of (lS)-4,4-difluoro-N-(3-hydroxy-l-phenylpropyI) cyclohexane carboxamide:
HOBT (1-Hydroxybenzotriazole hydrate) (4.4 g, 0.033 mole), MDC (75 mL) and 4, 4-difluoro cyclohexane carboxylic acid of Formula V (5.0 g, 0.030 mole) was charged at about 25°C to 30°C. Cooled to about 10°C to 15°C. (S)-3-amino-3-phenylpropan-l-ol of Formula VI (4.5 g, 0.030 mole) was added to reaction mass at about 0°C to 5°C. N-methyl morpholine (2.46 g, 0.024 mole) was added to reaction mass at about 10°C to 15°C. Reaction was stirred at about 10°C to 15°C. Solution of DCC (1,3-dicyclohexyldiimide) (6.2 g, 0.030 mole) in 10 mL of MDC (10 mL) was added at about 10°C to 15°C. Reaction was stirred at about 10°C to 15°C. After completion of reaction, the reaction mass was filtered and washed with MDC and sodium carbonate at about 15°C to 20°C. Organic layer washed with citric acid at about 20°C to 30°C and distilled out solvents under vacuum at about 30°C to 35°C to get solid residue. DIPE (20 mL) was added to residue and stirred at about 25 °C to 30°C. Residue was then filtered and washed with DIPE then dried the wet product under vacuum at about 30°C to 35°C to obtain compound of Formula VII.
Example-2: Preparation of (lS)-4,4-difluoro-N-(3-hydroxy-l-phenylpropyI) cyclohexane carboxamide:
4,4-difiuoro cyclohexane carboxylic acid of Formula V (5.0 g 0.030 mole) and ethyl acetate (35 mL) was cooled at about 0°C to 5°C. Triethyl amine (5.5 g, 0.054 mole) was added to reaction mass at about 0°C to 5°C. Reaction was stirred at about 0°C to 5°C. Ethyl chloroformate (3.3 g, 0.030 mole) in Ethyl acetate (1.5 mL) was added at about 0°C to 5°C. Reaction was stirred at about 0°C to 5°C. (S)-3-amino-3-phenylpropan-l-ol of Formula VI (7.08 g, 0.047 mole) was charged at about 0°C to 5°C. DMF (11.36 mL) was added to reaction mass at about 0°C to 5°C. Reaction was stirred at 0°C to 5°C. Water was added to reaction mass at about 0°C to 5°C. Separated layers. Aqueous layer was extracted with ethyl acetate at about 0°C to 5°C. Combined both organic layers and washed with water. Organic layer washed with dil. HC1 solution. Organic layer washed with water. Organic layer washed with saturated sodium bicarbonate solution at about 10°C to 15°C. Organic layer washed with water and brine solution, dried over anhydrous sodium sulphate and distilled to obtain compound of Formula VII.

Example-3: Preparation of (lS)-4,4-difluoro-N-(3-oxo-l-phenylpropyl) cyclohexane carboxamide:
Potassium bromide (0.320,0.0026 mole) and TEMPO (0.09 g, 0.0006 mole) was taken in MDC and water at about 25°C to 30°C. (1 S)-4,4-difluoro-N-(3-hydroxy-1-phenylpropyl) cyclohexane carboxamide of Formula VII (20.0 g, 0.067 mole) was added to reaction mass at about 25°C to 30°C. Sodium hypochlorite solution and NaHC03 were added at about 0°C to 5°C and stirred at about 10°C to 15°C. Sodium thiosulphate solution in water was added to reaction mass at about 10°C to 15°C. Separated the layers and extracted with MDC. Combined the organic layers and distilled out solvent under vacuum to obtain a compound of Formula III.
Example-4: Preparation of Maraviroc:
3-(3-isopropyl-5-methyl-4H-l,2,4-triazol-4-yl)-exo-8-azabicyclo [3.2.1] octane phosphate salt of Formula II (21 g 0.063 mole) and MDC (110 mL) was stirred at temperature at about 25°C to 30°C under nitrogen atmosphere. (IS) 4,4-difluoro-N-(3-oxo-l-phenylpropyl) cyclohexane carboxamide of Formula III (14.8 g, 0.050 mole) in 50 mL of MDC (50 mL) was added at about 25°C to 30°C. Sodium triacetoxy borohydride (12.74 g, 0.060 mole) was added lot wise to reaction mass at about 25°C to 30°C. Reaction mass was stirred at about 25°C to 30°C. Water was added after completion of reaction at about 25°C to 30°C. Reaction mass was settled and layers were separated. Aqueous layer was extracted with MDC. Both organic layers were combined and washed with 1M KOH solution at about 25°C to 30°C. Organic layer washed with water and with brine solution. Solution of o-phosphoric acid in water was added to organic layer at about 20°C to 25°C. Aqueous and organic layers were separated. Aqueous layer washed with MDC. Solution of sodium carbonate in water was added to the aqueous layer at about 20°C to 25°C. MDC was added to extract the product at about 25°C to 30°C. Aqueous and organic layers were separated. Aqueous layer extracted with MDC. Both layers were combined, dried over anhydrous sodium sulphate and distilled out solvents under vacuum to get Maraviroc compound of Formula I.

We claim:
1. A process for preparation of Maraviroc of Formula I, comprising
reacting a compound of Formula II
2. The compound of Formula II

3. A process for preparation of a compound of Formula II, comprising
reacting a compound of Formula IV with o-phosphoric acid. 4. A process for preparation of Maraviroc comprising steps of
a) preparation of compound of Formula VII
b) reacting a compound of Formula V with compound of Formula VI in presence of 1 -hydroxybenzotriazole hydrate (HOBT) and 1,3-dicyclohexyldiimide (DCC) to get compound of Formula VII

5. The process as claimed in claim 4, wherein the reaction between a compound of Formula V with compound of Formula VI in presence of 1-hydroxybenzotriazole hydrate (HOBT) and 1,3-dicyclohexyldiimide (DCC) is performed at temperature of about 20°C to about 40°C.
6. A process for preparation of Maraviroc comprising steps of

a) preparation of compound of Formula VII
b) reacting compound of Formula VIII with compound of Formula VI to get compound of Formula VII