Field of the invention
The present invention provides a process for preparation of fluorinated aromatic compounds of formula I.
Formula I
wherein "Z" represents carbon or nitrogen atom, "R" may be selected from hydrogen, alkyl, halogen, cyano, nitro, alkoxy, hydroxy and combination thereof, n represent 0-4.
Background of the invention
The fluorinated aromatic compounds of formula I are important intermediates for preparation of agrochemicals and pharmaceutical compounds.
E.P. Patent No. 0,734,363 Bl describes a process for fluorination of p-tolunitrile using fluorine gas diluted with nitrogen, in presence of formic acid to produce fluorinated p-tolunitrile.
The main disadvantage of the above process is that fluorine is very difficult to handle at commercial scale and also leads to the formation of undesired isomers.
Object of the invention
The main object of the present invention is to provide an industrially advantageous, cost effective, simple and alternate process for preparation of compound of formula I.
Formula I

wherein "Z" represents carbon or nitrogen atom, "R" may be selected from hydrogen, alkyl, halogen, cyano, nitro, alkoxy, hydroxy and combination thereof, n represent 0-4.
Summary of the invention A first aspect of the present invention is to provide a process for preparation of a compound of formula I,
Formula I
wherein "Z" represents carbon or nitrogen atom, "R" may be selected from hydrogen, alkyl, halogen, cyano, nitro, alkoxy, hydroxy and combination thereof, n represent 0-4, comprising the steps of:
a) reducing a compound of formula IV in a non-alcoholic solvent using hydrogen in presence of a catalyst to give a compound of formula III;
Formula IV Formula III
wherein Z, R and n are as defined above,
b) diazotizing the compound of formula III using a diazotizing agent to obtain first reaction mixture;
c) reacting the first reaction mixture with a fluoroborating agent to obtain a compound of formula II; and

Formula II wherein Z, R and n are as defined above, d) decomposing the compound of formula II to obtain the compound of
formula I. Second aspect of the present invention is to provide a process for preparation of a compound of formula I,
Formula I
wherein "Z" represents carbon or nitrogen atom, "R" may be selected from hydrogen, alkyl, halogen, cyano, nitro, alkoxy, hydroxy and combination thereof, n represent 0-4, comprising the step of decomposing a compound of formula II,
Formula II wherein Z, R and n are as defined above.
Third aspect of the present invention is to provide a process for preparation of a compound of formula I,

Formula I
wherein "Z" represents carbon or nitrogen atom, "R" may be selected from hydrogen, alkyl, halogen, cyano, nitro, alkoxy, hydroxy and combination thereof, n represent 0-4,
comprising the steps of: a) diazotizing the compound of formula III,
Formula III
wherein Z, R and n are as defined above, using a diazotizing agent to obtain a first reaction mixture; b) reacting the first reaction mixture of step a) with a fluoroborating agent to
obtain a compound of formula II; and
Formula II wherein Z, R and n are as defined above, c) decomposing the compound of formula II to obtain the compound of formula
I.
Fourth aspect of the present invention is to provide a process for preparation of a compound of formula I,

Formula I
wherein "Z" represents carbon or nitrogen atom, "R" may be selected from hydrogen, alkyl, halogen, cyano, nitro, alkoxy, hydroxy and combination thereof, n represent 0-4, comprising the steps of: a) reducing a compound of formula IV in a non-alcoholic solvent in presence of hydrogen and a catalyst to give a compound of formula III;
Formula IV Formula III
wherein Z, R andn are as defined above,
b) isolating compound of formula III, having purity greater than 97%;
c) converting the compound of formula III to the compound of formula I.
Detailed description of the invention
As used herein, the term "alkyl" includes methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, tert-butyl and the like.
As used herein, "step of diazotizing" refers to a process of converting aromatic amine into its diazonium salt, using a diazotizing agent in presence of acid.
As used herein, the "acid" may be selected from sulfuric acid, hydrochloric acid, hydrofluoric acid, hydrobromic acid and hydroiodic acid or a mixture thereof.

As used herein, the "diazotizing agent" refers to a group consisting of alkali metal nitrite, nitrous acid, nitrous anhydride, nitrous halide, and nitrous oxide. The preferred diazotizing agents are sodium nitrite and potassium nitrite.
The diazotization reaction of the present invention is carried out at a temperature selected in the range of 0 to 15°C within a time period selected from 30 minutes to 4 hours.
As used herein, the "fluoroborating agent" refers to fluoroboric acid, sodium tetrafluoroborate, potassium tetrafluoroborate, ammonium tetrafluoroborate, lithium tetrafluoroborate, rubidium tetrafluoroborate or the like.
The conversion of compound of formula III to compound of formula II is carried out at a temperature selected from 0 to 15°C within a time period selected from 30 minutes to 4 hours.
In another embodiment of the present invention the compound of formula III is converted to compound of formula II, wherein the compound of II is isolated as a solid product.
Additionally, the compound of formula III is converted into compound of formula II in presence of water.
As used herein, the step of "decomposing" refers to thermal decomposition of the diazonium salt in an organic solvent.
The decomposition of compound of formula II to a compound of formula I is carried out at a temperature selected from 40 to 75°C in a time period of 30 minutes to 4 hours.
The organic solvent used for thermal decomposition is selected from the group consisting of heptane, hexane, pentane, tetrahydrofuran, methyl tert-butyl ether, iso-propyl ether and the like.
As used herein, the step of isolation is done by chemical separation, acid-base neutralization, decantation, distillation, evaporation, column chromatography and filtration or combinations of these procedures thereof.
The process of reduction of compound of formula IV is carried out using hydrogen gas in presence of a catalyst in a non-alcoholic solvent.

The catalyst used in the reaction can be a metal catalyst on carbon. The metal catalyst can be selected from VIII block metals like palladium, platinum, rhodium, ruthenium, nickel, or VIII block metals impregnated on activated carbon and alike.
The catalyst can preferably be selected from palladium on carbon (Pd/C), platinum on carbon (Pt/C), rhodium on carbon (Rh/C) and alike.
The concentration of the catalyst may vary from 1 to 10% loading on carbon. Particularly, when 5% of Pd/C is used as a catalyst, then it is recycled for four folds as compare to 10% Pd/C. Optionally, water may be added in the reactor along with the catalyst.
It is advantageous to carry out the reduction reaction in presence of non-alcoholic solvent, because use of non-alcoholic solvent control the reduction of the desired product thereby avoiding impurities formation.
The non-alcoholic solvent can be selected from water, hydrocarbon solvent, cyclic ethers, esters and alike. The hydrocarbon solvent can be selected from aliphatic and aromatic hydrocarbons such as toluene, hexane, heptane and alike or a mixture thereof. The cyclic ether solvent can be selected from tetrahydrofuran, 1,4 dioxane and alike or mixture thereof. The ester solvent can be selected from ethyl acetate, methyl acetate and alike or mixture thereof.
The reduction reaction is carried out at a temperature in the range of 40°C to 60°C and pressure in the range of 5 to 15 kg/cm2.
In a preferred embodiment, compound of formula III is prepared from compound of formula IV with a purity greater than 97%.
A preferred embodiment of first to fourth aspects of the present invention provides a process for preparation of a compound of formula I, wherein, Z is carbon, n is 2 and R is a methyl and a cyano group, wherein, methyl is at a position ortho to ring fluorine and para to the cyano group on the ring, as represented below.

In a specific embodiment of first aspect, the present invention provides a process for preparation of 3-fluoro-4-methylbenzonitrile, comprising the steps of:
a) reducing 3-nitro-4-methylbenzonitrile in a non-alcoholic solvent using hydrogen in presence of a catalyst to give 3-amino-4-methylbenzonitrile;
b) diazotizing 3-amino-4-methylbenzonitrile using a diazotizing agent to obtain a first reaction mixture;
c) reacting the first reaction mixture with a fluoroborating agent to obtain 2-methyl-5-cyanobenzenediazonium tetrafluoroborate; and
d) decomposing 2-methyl-5-cyanobenzenediazonium tetrafluoroborate to obtain 3-fluoro-4-methylbenzonitrile.
In a specific embodiment of second aspect, the present invention provides a process for preparation of 3-fiuoro-4-methylbenzonitrile, comprising the steps of decomposing 2-methyl-5-cyanobenzenediazonium tetrafluoroborate.
In a specific embodiment of third aspect, the present invention provides a process for preparation of 3-fluoro-4-methylbenzonitrile,
comprising the steps of:
a) diazotizing 3-amino-4-methylbenzonitrile using a diazotizing agent to obtain a first reaction mixture;
b) reacting the first reaction mixture of step a) with a fluoroborating agent to obtain 2-methyl-5-cyanobenzenediazonium tetrafluoroborate;
c) decomposing 2-methyl-5-cyanobenzenediazonium tetrafluoroborate to obtain 3-fluoro-4-methylbenzonitrile.

In a specific embodiment of fourth aspect, the present invention provides a process for preparation 3-fluoro-4-methylbenzonitrile, comprising the steps of:
a) reducing 3-nitro-4-methylbenzonitrile in a non-alcoholic solvent in presence of hydrogen and a catalyst to give 3-amino-4-methylbenzonitrile;
b) isolating 3-amino-4-methylbenzonitrile, having purity greater than 97%;
c) converting 3-amino-4-methylbenzonitrile to 3-fluoro-4-methylb enzonitril e.
The starting material i.e. the compounds of formula IV is commercially available or can be prepared by the method as disclosed in Tetrahedron Letters, 52(52), 7038-7041; 2011.
Embodiments of the invention are not mutually exclusive, but may be implemented in various combinations. The described embodiments of the invention and the disclosed examples are given for the purpose of illustration rather than limitation of the invention as set forth in the appended claims.
Unless stated to the contrary, any of the words "comprising", "comprises" and includes mean "including without limitation" and shall not be construed to limit any general statement that it follows to the specific or similar items or matters immediately following it.
The following example is given by way of illustration and therefore should not be construed to limit the scope of the present invention.
EXAMPLES 1. Preparation of 3-amino-4-methylbenzonitrile
A solution of 3-nitro-4-methylbenzonitrile (20g) in toluene (200ml) was added in an autoclave reactor. Then, 5% Pd/C (0.26g) along with water (1.6g) was added to the reactor at a temperature of 27°C. Hydrogen gas was flushed into the reactor. The pressure of the reactor was raised to 10 Kg/cm2 and temperature was

raised to 50°C. After reaction completion, ensured by HPLC analysis, the reaction mass was cooled to 30°C. The reaction mass was filtered and the filtered mother liquor was concentrated under reduced pressure to obtain 15.9g of the titled compound and having 99% purity by HPLC.
2. Preparation of 2-methyl-5-cyanobenzenediazonium tetrafluoroborate
salt
An aqueous solution of hydrochloric acid (32mL; 35%) was slowly added to a solution of 3-amino-4-methylbenzonitrile (19g; 93%) in water (60mL) at a temperature of about 10-15°C. The reaction mass was cooled to 0-5°C and an aqueous solution of sodium nitrite (11 g of sodium nitrite in 15 mL of water) was slowly added to the reaction mixture at temperature of below 5°C. The reaction mass was further stirred at 0-5°C for 30 minutes. Fluoro boric acid solution (59 g of 40%>) was added to the reaction mixture at a temperature of below 10°C to form a thick slurry of reaction mixture of diazonium tetrafluoroborate. The slurry was filtered using buchner funnel and washed consecutively with cold water (20 mL; 5-10°C), methanol (60-75 mL), and diethyl ether (50-75 mL). The tetrafluoroborate salt so obtained was dried under vacuum at 25-30°C in lOOmmHg for 20-30 minutes. Yield: 85% Purity (by HPLC): 97.81%
3. Preparation of 3-fluoro-4-methyl benzonitrile
The tetrafluoroborate salt obtained from step 1, is decomposed using heptane (300mL) and heated at 65-70°C. When the white fumes of boron trifluoride commenced to appear, the heating was stopped and the decomposition was allowed to proceed spontaneously. The boron trifluoride generated in the reaction was absorbed using water traps and other gases were removed using nitrogen purging. The heptane layer thus obtained contains crude 3-fluoro-4-methyl benzonitrile.
Purity (by HPLC): 97.8% Recrystallization of crude product:

The heptane layer (235g) containing crude 3-fluoro-4-methyl benzonitrile (4.8%) was concentrated to 30g under 110 mmHg vacuum at 55 °C. The obtained heptane layer containing 35-40 % 3-fluoro-4-methyl benzonitrile was cooled to 8 °C under vigorous stirring and filtered to get pure 3-fluoro-4-methyl benzonitrile.
Yield: 51.5%
Purity (by HPLC): 99.6%
4. Preparation of 3-amino-4-isopropylbenzonitrile
A solution of 3-nitro-4-isopropylbenzonitrile (lOg) in toluene (110ml) was added in an autoclave reactor. Then, 5% Pd/C (0.12g) along with water (lg) was added to the reactor at a temperature of 25-27°C. Hydrogen gas was flushed into the reactor. The pressure of the reactor was raised to 10 Kg/cm2 and temperature was slowly raised to 50°C. After reaction completion was analysed HPLC, then reaction mass was cooled to 30°C. The reaction mass was filtered and filtrate liquor was concentrated under reduced pressure to obtain 8.1g of the titled compound and having 99% purity by HPLC.
5. Preparation of 2-isopropyl-5-cyanobenzenediazonium
tetrafluoroborate salt
An aqueous solution of hydrochloric acid (32mL; 35%) was slowly added to a solution of 3-amino-4-isopropylbenzonitrile (19g; 93%) in water (60mL) at a temperature of about 10-15°C. The reaction mass was cooled to 0-5°C and an aqueous solution of sodium nitrite (11 g of sodium nitrite in 15 mL of water) was slowly added to the reaction mixture at temperature of below 5°C. The reaction mass was further stirred at 0-5°C for 30 minutes. Aqueous solution of Potassium tetrafluoroborate was added to the reaction mixture at a temperature of below 10°C to form a thick slurry of reaction mixture of diazonium tetrafluoroborate. The slurry was filtered using buchner funnel and washed consecutively with cold water (20 mL; 5-10°C), methanol (75 mL), and diethyl ether (90 mL). The tetrafluoroborate

salt so obtained was dried under vacuum at 25-30°C in lOOmmHg for 20-30
minutes.
Yield: 90%
Purity (by HPLC): 97.81%
6. Preparation of 3-fluoro-4-isopropyl benzonitrile
The 2-isopropyl-5-cyanobenzenediazonium tetrafluorob orate salt is decomposed using heptane (250mL) and heated to 65°C. When the white fumes of boron trifluoride commenced to appear, the heating was stopped and the decomposition was allowed to proceed spontaneously. The boron trifluoride generated in the reaction was absorbed using water traps and other gases were removed using nitrogen purging. The heptane layer thus obtained contains crude 3-fluoro-4-isopropyl benzonitrile.
Purity (by HPLC): 98.8% Recrystallization of crude product:
The heptane layer (220g) containing crude 3-fluoro-4-isopropyl benzonitrile was concentrated to 42g under 110 mmHg vacuum at 55 °C. The obtained heptane layer containing 35-40 % 3-fluoro-4-isopropyl benzonitrile was cooled to 8 °C under vigorous stirring and filtered to get pure 3-fluoro-4-isopropyl benzonitrile.
Yield: 65-70%
Purity (by HPLC): 99.6%
7. Preparation of 3-amino-4-methylchlorobenzene
A solution of 3-nitro-4-methychlorobenzene (lOg) in 1,4-dioxane (150ml) was added in an autoclave reactor. 5% Pd/C (0.12g) along with water (l.lg) was added to the reactor at a temperature of up to 27°C. Hydrogen gas was purged into the reactor. The pressure of the reactor was raised to 10 Kg/cm2 and temperature was slowly raised to 50°C. After reaction completion was analysed HPLC, then reaction mass was cooled to 30°C. The reaction mass was filtered and filtrate liquor was concentrated under reduced pressure to obtain 8.0g of the titled compound. Purity: >98%

8. Preparation of 3-fluoro-4-methoxyaniline
A solution of 2-fluoro-l-methoxy-4-nitrobenzene (15g) in tetrahydrofuran (120ml) was added in an autoclave reactor. 5% Pd/C (0.18g) along with water (1.3g) was added to the reactor at a temperature of up to 27°C. Hydrogen gas was purged into the reactor. The pressure of the reactor was raised to 10 Kg/cm2 and temperature was slowly raised to 50°C. After reaction completion was analysed HPLC, then reaction mass was cooled to 30°C. The reaction mass was filtered and filtrate liquor was concentrated under reduced pressure to obtain 12g of the titled compound. Yield: > 99% Purity: >99%
9. Preparation of 3-fluoro-4-methoxybenzenediazonium tetra
fluoroborate salt
An aqueous solution of hydrochloric acid (22mL; 35%) was slowly added to a solution of 3-fluoro-4-methoxyaniline (12g; 93%) in water (60mL) at a temperature of about 10-15°C. The reaction mass was cooled to 0-5°C and an aqueous solution of sodium nitrite (6.36 g of sodium nitrite in 10 mL of water) was slowly added to the reaction mixture at temperature of below 5°C. The reaction mass was further stirred at 0-5°C for 30 minutes. Fluoro boric acid solution (35g of 40%)was added to the reaction mixture at a temperature of below 10°C to form a thick slurry of reaction mixture of diazonium tetrafluoroborate. The slurry was filtered using buchner funnel and washed consecutively with cold water (20 mL; 5-10°C), methanol (60-75 mL), and diethyl ether (50-75 mL). The tetra fluoroborate salt so obtained was dried under vacuum at 25-30°C in lOOmmHg for 20-30 minutes. Yield: 92% Purity (by HPLC): 98.1%

10. Preparation of 2,4-difluoroanisole
The 3-fluoro-4-methoxybenzenediazonium tetrafluoroborate salt
salt of example 9 is decomposed using heptane (200mL) and heated at 65-70°C. When the white fumes of boron trifluoride commenced to appear, the heating was stopped and the decomposition was allowed to proceed spontaneously. The boron trifluoride generated in the reaction was absorbed using water traps and other gases were removed using nitrogen purging. The heptane layer thus obtained contains crude 2,4-difluoroanisole
Purity (by HPLC): 97.8% Recrystallization of crude product:
The heptane layer containing crude 2,4-difluoroanisole (4.8%) was concentrated to 30g under 110 mmHg vacuum at 55 °C. The obtained heptane layer containing 35-40 % 2,4-difluoroanisole was cooled to 8 °C under vigorous stirring and filtered to get pure 2,4-difluoroanisole .
Yield: 70 %
Purity (by HPLC): 99.6%
11. Preparation of 3-fluoro-4-methoxybenzenediazoniumtetrafluoro
borate salt
An aqueous solution of hydrochloric acid (20mL; 35%) was slowly added to a solution of 3-fluoro-4-methoxyaniline (lOg; 90%) in water (40mL) at a temperature of about 15°C. The reaction mass was cooled to 0-5°C and an aqueous solution of sodium nitrite (6.0g of sodium nitrite in 10 mL of water) was slowly added to the reaction mixture at temperature of below 5°C. The reaction mass was further stirred at 0-5°C for 30 minutes. Aqueous solution of Potassium tetrafluorob orate borate was added to the reaction mixture at a temperature of below 10°C to form a thick slurry of reaction mixture of diazonium tetrafluorob orate. The slurry was filtered using buchner funnel and washed consecutively with cold water (20 mL; 5-10°C), methanol (60-75 mL), and diethyl ether (50-75 mL).

The tetrafluoroborate salt so obtained was dried under vacuum at 25-30°C in lOOmmHg for 20-30 minutes. Yield: 90% Purity (by HPLC): 98.1%
12. Preparation of 3-fluoro-4-methoxybenzenediazoniumtetrafluoro
borate salt
An aqueous solution of hydrochloric acid (20mL; 35%) was slowly added to a solution of 3-fluoro-4-methoxyaniline (lOg; 90%%) in water (40mL) at a temperature of about 15°C. The reaction mass was cooled to 0-5°C and an aqueous solution of potassium nitrite (6.0g of potassium nitrite in 10 mL of water) was slowly added to the reaction mixture at temperature of below 5°C. The reaction mass was further stirred at 0-5°C for 30 minutes. Aqueous solution of potassium tetrafluorob orate was added to the reaction mixture at a temperature of below 10°C to form a thick slurry of reaction mixture of diazonium tetra fluoroborate. The slurry was filtered using buchner funnel and washed consecutively with cold water (20 mL; 5-10°C), methanol (60-75 mL), and diethyl ether (50-75 mL). The tetrafluorob orate salt so obtained was dried under vacuum at 25-30°C in lOOmmHg for 20-30 minutes. Yield: 94% Purity (by HPLC): 98%
13. Preparation of 3-fluoro-5-methylbenzenediazonium tetrafluoroborate
salt
An aqueous solution of hydrochloric acid (20mL; 35%) was slowly added to a solution of 3-fluoro-5-methylaniline (lOg; 90%%) in water (40mL) at a temperature of about 15°C. The reaction mass was cooled to 0-5°C and an aqueous solution of potassium nitrite (7g of potassium nitrite in 15 mL of water) was slowly added to the reaction mixture at temperature of below 5°C. The reaction mass was further stirred at 0-5°C for 30 minutes. Aqueous solution of potassium tetrafluoroborate

was added to the reaction mixture at a temperature of below 10°C to form a thick
slurry of reaction mixture of diazonium tetrafluoroborate. The slurry was filtered
using buchner funnel and washed consecutively with cold water (20 mL; 5-10°C),
methanol (75 mL), and diethyl ether (75 mL). The tetrafluorob orate salt so obtained
was dried under vacuum at 25-30°C in lOOmmHg for 20-30 minutes.
Yield: 95%
Purity (by HPLC): 98.1%
14. Preparation of 2,5-difluorotoluene
4-fluoro-2-methylbenzenediazonium tetrafluorob orate salt is decomposed using isopropyl ether (200mL) and heated at 65-70°C. When the white fumes of boron trifluoride commenced to appear, the heating was stopped and the decomposition was allowed to proceed spontaneously. The boron trifluoride generated in the reaction was absorbed using water traps and other gases were removed using nitrogen purging. The isopropyl ether layer thus obtained contains crude 2,5-difluoroanisole. The isopropyl ether layer containing crude 2,5-difluorotoluene was concentrated under 110 mmHg vacuum at 55 °C. The obtained isopropyl ether layer containing 2,5-difluorotoluene was cooled to 8 °C under vigorous stirring and filtered to get pure 2,5-difluorotoluene. Yield: >80% Purity (by HPLC): 97.8%

WE CLAIM:
1. A process for preparation of a compound of formula I,
Formula I
wherein "Z" represents carbon or nitrogen atom, "R" may be selected from hydrogen, alkyl, halogen, cyano, nitro, alkoxy, hydroxy and combination thereof, n represent 0-4, the process comprising the steps of:
a) reducing a compound of formula IV in a non-alcoholic solvent using hydrogen in presence of a catalyst to give a compound of formula III;
Formula IV Formula III
wherein Z, R and n are as defined above,
b) diazotizing the compound of formula III using a diazotizing agent to obtain first reaction mixture;
c) reacting the first reaction mixture with a fiuoroborating agent to obtain a compound of formula II; and
Formula II wherein Z, R and n are as defined above,

d) decomposing the compound of formula II to obtain the compound of formula I.
2. A process for preparation of a compound of formula I,
Formula I
wherein "Z" represents carbon or nitrogen atom, "R" may be selected from hydrogen, alkyl, halogen, cyano, nitro, alkoxy, hydroxy and combination thereof, n represent 0-4, comprising the step of decomposing a compound of formula II,
Formula II wherein Z, R and n are as defined above.
3. A process for preparation of a compound of formula I,
Formula I
wherein "Z" represents carbon or nitrogen atom, "R" may be selected from hydrogen, alkyl, halogen, cyano, nitro, alkoxy, hydroxy and combination thereof, n represent 0-4,

comprising the steps of:
a) diazotizing the compound of formula III,
Formula III
wherein Z, R and n are as defined above, using a diazotizing agent to obtain a first reaction mixture; b) reacting the first reaction mixture of step a) with a fluoroborating agent to
obtain a compound of formula II; and
Formula II wherein Z, R and n are as defined above, c) decomposing the compound of formula II to obtain the compound of formula
I. 4. A process for preparation of a compound of formula I,
Formula I
wherein "Z" represents carbon or nitrogen atom, "R" may be selected from hydrogen, alkyl, halogen, cyano, nitro, alkoxy, hydroxy and combination thereof, n represent 0-4, comprising the steps of:

a) reducing a compound of formula IV in a non-alcoholic solvent in
presence of hydrogen and a catalyst to give a compound of formula III;
Formula IV Formula III
wherein Z, R andn are as defined above,
b) isolating compound of formula III, having purity greater than 97%;
c) converting the compound of formula III to the compound of formula I.

5. The process as claimed in claim 1 and 2, wherein, the organic solvent is selected from a group consisting of heptane, hexane, pentane, tetrahydrofuran, methyl tert-butyl ether and iso-propyl ether or a mixture thereof.
6. The process as claimed in claim 1 and 3, wherein, the diazotizing agent is selected from a group consisting of sodium nitrite or potassium nitrite, nitrous acid, nitrous anhydride, nitrous halide and nitrous oxide.
7. The process as claimed in claim 1 and 3, wherein, fluoroborating agent is selected from a group consisting of fluoroboric acid, sodium tetrafluoroborate, potassium tetrafluorob orate, ammonium tetrafluoroborate, lithium tetrafluoroborate and rubidium tetrafluoroborate.
8. The process as claimed in claim 1 and 4, wherein, non-alcoholic solvent is selected from a group consisting of hydrocarbon solvent, cyclic ethers and esters or a mixture thereof.

9. The process as claimed in claim 1, wherein, the catalyst is selected from a group consisting of palladium, platinum, rhodium, ruthenium, nickel, palladium on carbon, platinum on carbon and rhodium on carbon.