This patent application claims the benefit of priority to Indian Provisional Patent Application No. 201841039870, filed on October 22, 2018, which is incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates to novel, cost effective and industrially advantageous processes for the production of 3-Fluoro-4-(4-morpholinyl)aniline with high yield and purity using cheaper raw materials and reagents.
BACKGROUND OF THE INVENTION
U.S. Patent No. 5,688,792 (hereinafter referred to as the US'792 patent), assigned to Pharmacia & Upjohn Company, discloses a variety of oxazine and thiazine oxazolidinone derivatives and their stereo chemically isomeric forms, processes for their preparation, pharmaceutical compositions comprising the derivatives, and method of use thereof. Among them, Linezolid, a member of the oxazolidinone class of drugs and chemically named as N-[[(5S)-3-[3-fluoro-4-(4-morpholinyl)phenyl]-2-oxo-5-oxazoIidinyl]methyl]acetamide, is active against most Gram-positive bacteria that cause disease, including streptococci, vancomycin-resistant enterococci (VRE), and methicillin-resistant Staphylococcus aureus (MRSA). Linezolid is represented by the following structural formula:

In the synthesis of Linezolid, 3-Fluoro-4-(4-morpholinyl)aniline is a key intermediate. Various processes for the preparation of 3-Fluoro-4-(4-morpholinyl)aniline were reported in U.S. Patent Nos. US 5,688,792, US 7,429,661, US 7,307,163; PCT Publication Nos. WO 2012/114355, and WO 2015/162622; Chinese Patent Application Publication Nos. CN 103103229, and CN101659645B; and Journal Article: J. Med. Chem. 39(3), 673-679,1996.
The synthesis of 3-Fluoro-4-(4-morpholinyl)aniline disclosed in the US'792 patent is depicted in the below scheme-1:
The synthesis of 3-Fluoro-4-(4-morpholinyl)aniline as described in the US'792 patent involves the following reaction steps: a) 3,4-Difluoronitrobenzene is reacted with morpholine in the presence of diisopropylethylamine in ethyl acetate solvent to produce 3-fluoro-4-morpholinyl-nitrobenzene as a pale yellow solid; and b) a suspension of 3-fluoro-4-morpholinylnitrobenzene, ammonium formate in tetrahydrofuran and methanol is hydrogenated using hydrogen gas in the presence of Pd/C catalyst under nitrogen atmosphere, followed by tedious work up procedures to produce 3-Fluoro-4-(4-morpholinyl)aniline as a brown solid.

However, the process described in the US'792 patent is not commercial viable since it suffers from the following disadvantages and limitations: i) the process involves the use of expensive raw materials such as 3,4-difluoronitrobenzene; and ii) the process involves the use of highly combustible solvents like tetrahydrofuran.
Chinese Patent No. CN101659645 (hereinafter referred to as CN'645 patent) discloses a process for the preparation of 3-Fmoro-4-(4-moipholmyl)aniIine, which is depicted in the below scheme-2:
However, the process described in the CN'645 patent is not commercial viable since it suffers from the following disadvantages and limitations: i) the process involves the use of expensive raw materials like bis(chloroethyl)ether; and ii) the process involves the use of highly combustible solvents like tetrahydrofuran.
The object of the present invention is to provide a novel, cost effective and industrially advantageous process for the preparation of 3-Fluoro-4-(4-morpholinyl)aniline with high yield and purity using cheaper raw materials and reagents to resolve the

problems associated with the processes described in the prior art, and that will be suitable for large-scale preparation.
SUMMARY OF THE INVENTION
In one aspect, provided herein are novel, cost effective and industrially advantageous process for the preparation of 3-Fluoro-4-(4-morpholinyl)aniline or a salt thereof.
The present inventors have surprisingly and unexpectedly found that 3-Fluoro-4-(4-morpholinyl)aniline or a salt thereof can be prepared by reduction of l-fluon>2-nitrobenzene with a suitable reducing agent in a suitable solvent to produce 2-fluoroaniline hydrochloride, which is then condensed with 2-chloroethanol in the presence of a suitable base and suitable catalyst to produce 2,2'-[(2-fluorophenyl)imino]bis[ethanol], followed by reaction with a dehydrating agent to produce 4-(2-fluorophenyl)morpholineJ which undergoes nitration using nitric acid to produce 3-fluoro-4-morpholinyl-nitrobenzene, which is finally reduced with a suitable reducing agent to produce 3-Fluoro-4-(4-morpholinyl)aniline or a salt thereof.
The novel process for the preparation of 3-Fluoro-4-(4-morpholinyl)aniline disclosed in the present invention is represented by a schematic diagram as depicted in scheme-3:

The processes for the preparation of 3-Fluoro-4-(4-morpholinyl)aniline disclosed herein have the following advantages over the processes described in the prior art: i) the processes involve the use of cheaper raw materials like 2-haloethanol; and avoid
the use of expensive raw materials like 3,4-difluoronitrobenzene and
bis(chloroethyl)ether; thereby making the process cost effective; ii) the overall yield and the purity of 3-Fluoro4-(4-morpholinyl)aniline are increased; iii) the processes avoid the use of highly combustible solvents like tetrahydrofuran; and iv) the processes involve easy work-up methods and simple isolation processes.
PET AILED DESCRIPTION OF THE INVENTION According to one aspect, there is provided a novel, cost effective and industrially advantageous process for the preparation of 3-Fluoro-4-(4-morphomayl)aniline of formula
or a salt thereof, which comprises:
a) reducing 1 -fluoro-2-nitrobenzene of formula II:
with a suitable reducing agent or an hydrogenation catalyst, optionally in the presence of a base, to produce 2-fluoroanline of formula III:

or a salt thereof;
reacting the compound of formula HI or a salt thereof with 2-haloethanol of formula
wherein 'X' is a halogen;
in the presence of a suitable base, and optionally in the presence of an alkali metal
halide as a catalyst, to produce 2,2'-[(2-fluorophenyl)imino]bis[ethanol] of formula V:
reacting the compound of formula V with a suitable dehydrating agent to produce 4-(2-fluorophenyl)morpholine of formula VI:
reacting the compound of formula VI with a suitable nitrating agent in the presence of a suitable solvent to produce 3-fluoro-4-morpholinyl-nitrobenzene of formula VII:
and;
reducing the compound of formula VII with a suitable reducing agent or a hydrogenation catalyst in a suitable solvent to produce 3-Fluoro-4-(4-morpholinyl)aniline of formula I or a salt thereof.

In one embodiment, the halogen atom 'X' in the compound of formula IV is selected from the group consisting of CI, Br and I. Most specifically, the halogen atom 'X' in the compound of formula IV is CI.
Salts of the compounds of formulae I and III as used herein include acid addition salts which are derived from an acid such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, oxalic acid, acetic acid, benzenesulfonic acid, toluene sulfonic acid, and the like.
Exemplary salts of the compounds of formulae I and III include, but are not limited to, hydrochloride, hydrobromide, sulfate, nitrate, acetate, oxalate, benzenesulfonate, toluene sulfonate, and the like. A most specific salt of the compounds of formulae I and III is hydrochloride salt.
Unless otherwise specified, the term 'base' as used herein includes organic bases and inorganic bases. Exemplary organic bases include, but are not limited to, triethyl amine, trimethylamine, N,N-diisopropylethylamine, N-methylmorpholine and N-methylpiperidine. Exemplary inorganic bases include, but are not limited to, aqueous ammonia, ammonia saturated in an organic solvent, sodium hydroxide, calcium hydroxide, magnesium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate,, lithium carbonate, sodium methoxide, sodium ethoxide, sodium tert-butoxide, sodium isopropoxide and potassium tert-butoxide, and the like.
Unless otherwise specified, the suitable solvent used for isolating, purifying and/or recrystallizing the compounds of formula I, II, III, V, VI and VII obtained by, or employed in, the processes described in the present invention is selected from the group consisting of water, an alcohol, a ketone, a polar aprotic solvent, an ether, an ester, a hydrocarbon, a halogenated hydrocarbon, a nitrile solvent, and mixtures thereof. Specifically, the solvent used for isolating, purifying and/or recrystallizing the compounds obtained by the processes described herein is selected from the group consisting of water, methanol, ethanol, 1-propanol, isopropyl alcohol, tetrahydrofuran, 2-methyl-tetrahydrofuran, diisopropyl ether, methyl tert-butyl ether, ethyl acetate, acetone, cyclohexane, toluene, xylene, dichloromethane, dichloroethane, chloroform, acetonitrile, dimethylformamide, acetic acid, dimethylacetamide, and mixtures thereof.

As used herein, the term "reflux temperature" means the temperature at which the solvent or solvent system refluxes or boils at atmospheric pressure.
As used herein, the term "room temperature" refers to a temperature of about 20°C to about 35CC. For example, "room temperature" can refer to a temperature of about 25°C to about 30°C.
In one embodiment, the reduction in step-(a) is carried out in the presence of hydrogen gas or a hydrogen source.
In another embodiment, the reduction in step-(a) is carried out by catalytic hydrogenation under hydrogen pressure in the presence of a suitable hydrogenation catalyst. Exemplary hydrogenation catalysts used in step-(a) include, but are not limited to, Raney nickel, palladium on carbon, platinum oxide, platinum on carbon, Pd(OH)2, Pd-BaSC>4 and the like. Specifically, the hydrogenation catalyst is Raney nickel or palladium on carbon, and a most specific hydrogenation catalyst is Raney nickel.
In another embodiment, the reduction in step-(a) is carried out by using a suitable reducing agent. Exemplary reducing agents used in step-(a) include, but are not limited to, palladium on carbon and ammonium formate, palladium on carbon and hydrazine hydrate, palladium on carbon and formic acid, palladium on carbon and cyclohexadiene, sodium hydro sulphite, FeCb and ammonium chloride, FeCl3 and hydrazine hydrate, iron powder and acetic acid, iron powder and HC1, Zinc dust and acetic acid, tin(II) chloride, Zinc dust and HC1, Zinc dust and ammonium formate, Zinc dust and ammonium chloride, sodium dithionite, Na2S, LiAlH^NiBBU, and the like.
Specifically, the reducing agent used in step-(a) is selected from the group consisting of sodium dithionite, palladium on carbon and cyclohexadiene, sodium hydro sulphite, FeCl3 and ammonium chloride, FeC^ and hydrazine hydrate, and iron powder and acetic acid.
The reaction in step-(a) is carried out in a suitable solvent. Exemplary solvents used in step-(a) include, but are not limited to, an alcohol, a nitrile solvent, an ester solvent, a polar aprotic solvent, and mixtures thereof.
Specifically, the solvent used in step-(a) is selected from the group consisting of methanol, ethanol, 1-propanol, isopropyl alcohol, acetonitrile, N,N-dimethylforrnamide,

N,N-dimethylacetamide, dimethylsulfoxide, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and mixtures thereof. A most specific solvent is methanol.
In one embodiment, the base used in step-(a) is an inorganic base selected from the group as described hereinabove. A most specific inorganic base used in the step-(a) is aqueous ammonia.
In one embodiment, the reaction in step-(a) is carried out at a temperature of about 20°C to the reflux temperature of the solvent used, specifically at a temperature of about 25°C to about 50°C. The reaction time may vary from about 3 hours to about 10 hours.
In another embodiment, the reaction in step-(a) is carried out under hydrogen pressure of about 1 kg/cm to about 10 kg/cm2, specifically under pressure of about 2 kg/cm2 to about 5 kg/cm2.
The reaction mass containing the 2-fluoroaniline of formula III or a salt thereof obtained in step-(a) may be subjected to usual work up methods such as a washing, an extraction, a pH adjustment, an evaporation, a layer separation, a decolorization, or a combination thereof. The reaction mass may be used directly in the next step to produce the compound of formula V, or the compound of formula III may be isolated and/or recrystallized and then used in the next step.
In a preferred embodiment, the compound of formula HI is isolated in the form of a hydrochloride salt.
In one embodiment, the reaction in step-(b) is carried out in the presence of a suitable solvent. Exemplary solvents used in step-(b) include, but are not limited to, water, an alcohol, a nitrile solvent, an ester solvent, a polar aprotic solvent, and mixtures thereof.
Specifically, the solvent used in step-(b) is selected from the group consisting of water, methanol, ethanol, 1-propanol, isopropyl alcohol, acetonitrile, N,N-dimethylformamide, N,N-dime1hylacetamide, dimethyl sulfoxide, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and mixtures thereof. A most specific solvent is water.
In one embodiment, the base used in step-(b) is an organic base or an inorganic base selected from the group as described hereinabove. Specifically, the base used in step-(b) is an inorganic base selected from the group consisting of aqueous ammonia, ammonia saturated in an organic solvent, sodium hydroxide, calcium hydroxide, magnesium

hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, sodium methoxide, sodium ethoxide, sodium tert-butoxide, sodium isopropoxide and potassium tert-butoxide. Most specifically, the base used in step-(b) is calcium hydroxide, sodium hydroxide, potassium hydroxide, calcium carbonate, sodium carbonate or potassium carbonate.
In another embodiment, the 'alkali metal halide' used as a catalyst in step-(b) is selected from the group consisting of sodium bromide, sodium iodide, potassium bromide and potassium iodide. A most specific alkali metal halide is potassium bromide or potassium iodide.
In another embodiment, the amount of the alkali metal halide employed in step-(b) is 1% w/w to about 8% w/w, specifically from about 3.5% w/w to about 5.5% w/w, with respect to the quantity of the 2-flouroanline of formula III or a salt thereof.
The reaction temperature and time period for condensation reaction in step-(b) will ordinarily depend on the starting compound and the solvent employed in the reaction.
In one embodiment, the reaction in step-(b) is carried out at a temperature of about 50°C to the reflux temperature of the solvent used, specifically at a temperature of about 60°C to the reflux temperature of the solvent used, and more specifically at the reflux temperature of the solvent used. The reaction time may vary from about 12 hours to about 75 hours.
The reaction mass containing the 2,2'-[(2-Fluorophenyl)imino]bis[ethanol] compound of formula V obtained in step-(b) may be subjected to usual work up methods such as a washing, an extraction, a pH adjustment, an evaporation, a layer separation, a decolorization, or a combination thereof. The reaction mass may be used directly in the next step to produce the compound of formula VI, or the compound of formula V may be isolated and/or recrystallized and then used in the next step.
In one embodiment, the dehydrating agent used in step-(c) is include, but are not limited to, sulphuric acid, calcium Oxide, phosphorous pentoxide, phosphoryl Chloride, para-toluene sulphonic acid, camphor sulphonic acid, and the like. A most preferred dehydrating agent is sulphuric acid.
In one embodiment, the reaction in step-(c) is carried out at a temperature of about 30°C to about 160°C, specifically at a temperature of about 40°C to about 155°C. The

reaction time may vary from about 30 minutes to about 3 hours, specifically from about 45 minutes to about 2 hours.
The reaction mass containing the 4-(2-fluorophenyl)morpholine compound of formula VI obtained in step-(c) may be subjected to usual work up such as a washing, an extraction, a pH adjustment, an evaporation, a layer separation, a decolorization, or a combination thereof. The reaction mass may be used directly in the next step to produce the compound of formula VII, or the compound of formula VI may be isolated and/or recrystallized and then used in the next step.
In one embodiment, the nitrating agent used in step-(d) include, but are not limited to, fuming nitric acid, sodium nitrate, potassium nitrate, copper(H) nitrate, barium nitrate and the like. A most specific nitrating agent is nitric acid.
Exemplary solvents used in step-(d) include, but are not limited, methanol, ethanol, 1-propanol, isopropyl alcohol, acetonitrile, N,N-dimethylformamide, acetic acid N,N-dimethylacetamide, dimethylsulfoxide, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and mixtures thereof A most specific solvent used in step-(d) is acetic acid.
hi one embodiment, the reaction in step-(d) is carried out at a temperature of about 0°C to 50°C, specifically at a temperature of about 5°C to about 35°C, and more specifically at a temperature of about 10°C to about 30°C. The reaction time may vary from about 5 hours to about 30 hours, and specifically from about 15 to about 25 hours.
The reaction mass containing the 3-fiuoro-4-morpholinyl-nitrobenzene compound of formula VII obtained in step-(d) may be subjected to usual work up such as a washing, an extraction, a pH adjustment, an evaporation, a layer separation, a decolorization, or a combination thereof. The reaction mass may be used directly in the next step to produce the compound of formula I, or the compound of formula VII may be isolated and/or recrystallized and then used in the next step.
In one embodiment, the reduction in step-(e) is carried out in the presence of hydrogen gas or a hydrogen source.
In another embodiment, the reduction in step-(e) is carried out by catalytic hydrogenation under hydrogen pressure in the presence of a suitable hydrogenation catalyst. Exemplary hydrogenation catalysts used in step-(e) include, but are not limited to, Raney nickel, palladium on carbon, platinum oxide, platinum on carbon, Pd(OH)2, Pd-

BaS04 and the like. Specifically, the hydrogenation catalyst is Raney nickel or palladium on carbon, and a most specific hydrogenation catalyst is Raney nickel.
In another embodiment, the reduction in step-(e) is carried out by using a suitable reducing agent. Exemplary reducing agents used in step-(e) include, but are not limited to, palladium on carbon and ammonium formate, palladium on carbon and hydrazine hydrate, palladium on carbon and formic acid, palladium on carbon and cyclohexadiene, sodium hydro sulphite, FeCb and ammonium chloride, FeCl3 and hydrazine hydrate, iron powder and acetic acid, iron powder and HC1, Zinc dust and acetic acid, tin(II) chloride, Zinc dust and HC1, Zinc dust and ammonium formate, Zinc dust and ammonium chloride, sodium dithionite, Na2S, LiAlH4| NiBH4, and the like.
Specifically, the reducing agent used in step-(e) is selected from the group consisting of sodium dithionite, palladium on carbon and cyclohexadiene, sodium hydro sulphite, FeCb and ammonium chloride, FeCh and hydrazine hydrate, and iron powder and acetic acid.
In one embodiment, the reaction in step-(e) is carried out in the presence of a reaction inert solvent. Exemplary solvents used in step-(e) include, but are not limited to, an alcohol, a nitrile solvent, an ester solvent, a polar aprotic solvent, and mixtures thereof.
Specifically, the solvent used in step-(e) is selected from the group consisting of methanol, ethanol, 1-propanol, isopropyl alcohol, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and mixtures thereof. A most specific solvent is ethyl acetate.
In another embodiment, the reaction in step-(e) is carried out under hydrogen pressure of about 1 kg/cm to about 10 kg/cm , specifically under pressure of about 2 kg/cm to about 5 kg/cm .
The reaction mass containing the 3-Fluoro-4-(4-morpholinyl)aniline of formula I obtained in step-(e) may be subjected to usual work up methods such as a washing, a quenching, an extraction, a pH adjustment, an evaporation, a layer separation, decolorization, a carbon treatment, or a combination thereof.
In one embodiment, the 3-Fluoro-4-(4-morpholinyl)aniline of formula I obtained in step-(e) may be isolated and/or re-crystallized from a suitable solvent by conventional methods such as cooling, seeding, partial removal of the solvent from the solution, by

adding an anti-solvent to the solution, evaporation, vacuum distillation, or a combination thereof.
The highly pure 3-Fluoro-4-(4-morpholinyl)aniline of formula I obtained by the above process may be further dried in, for example, a Vacuum Tray Dryer, a Rotocon Vacuum Dryer, a Vacuum Paddle Dryer or a pilot plant Rota vapor, to further lower residual solvents. In one embodiment, the drying is carried out at atmospheric pressure or reduced pressures, such as below about 200 mm Hg, or below about 50 mm Hg, at temperatures such as about 35°C to about 120°C, and specifically at about 75°C to about 85°C. The drying can be carried out for any desired time period that achieves the desired result, such as times about 1 to 20 hours.
According to another aspect, there is provided a novel, cost effective and industrially advantageous process for the preparation of 3-Fluoro-4-(4-morpholinyl)aniline
or a salt thereof, which comprises:
a) reacting 2-flouroaniline of formula III:
wherein 'X' is a halogen,
in the presence of a suitable base, and optionally in the presence of an alkali metal
halide as a catalyst, to produce 2,2'-[(2-fluorophenyl)imino]bis[ethanol] of formula V:

) reacting the compound of formula V with a suitable dehydrating agent to produce 4-(2-fluorophenyl)morpholine of formula VI:
reacting the compound of formula VI with a suitable nitrating agent in the presence of a suitable solvent to produce 3-fluoro-4-morpholinyl-nitrobenzene of formula VII:
and; d) reducing the compound of formula VII with a suitable reducing agent or a
hydrogenation catalyst in a suitable solvent to produce 3-Fluoro-4-(4-
morpholinyl)aniline of formula I or a salt thereof.
The preparation of 3-Fluoro-4-(4-morpholinyl)aniline of formula I or a salt thereof as described in the above process steps-(a), (b), (c) and (d) can be carried out by using the respective solvents, reagents, methods, parameters and conditions as described hereinabove.
According to another aspect, there is provided a novel, cost effective and industrially advantageous process for the preparation of 3-Fluoro-4-(4-morpholinyl)aniline of formula I:

or a salt thereof which comprises:
a) reacting 2,2'-[(2-fluoropheiiyl)imino]bis[ethanol] of formula V:
with a suitable dehydrating agent to produce 4-(2-fhiorophenyl)morpholirie of formula VI:
(b) reacting the compound of formula VI with a suitable nitrating agent in the presence of a suitable solvent to produce 3-fluoro-4-morpholinyl-nitrobenzene of formula VU:
and; (c) reducing the compound of formula VII with a suitable reducing agent or a
hydrogenation catalyst in a suitable solvent to produce 3-Fluoro-4-(4-
morpholinyl)aniline of formula I or a salt thereof.
The preparation of 3-Fluoro-4-(4-morpholinyl)aniline of formula I or a salt thereof as described in the above process steps-(a), (b) and (c) can be carried out by using the suitable solvents, reagents, methods, parameters and conditions as described hereinabove.
According to another aspect, there is provided a novel, cost effective and industrially advantageous process for the preparation of 3-Fluoro-4-(4-morpholinyl)aniline of formula I:

or a salt thereof which comprises:
a) reacting 4-(2-fluorophenyl)morpholine of formula VI:
with a suitable nitrating agent in the presence of a suitable solvent to produce 3-fTu.oro-4-morpholinyl-nitrobenzene of formula VII:
and; b) reducing the compound of formula VII with a suitable reducing agent or a
hydrogenation catalyst in a suitable solvent to produce 3-Fluoro-4-(4-
morpholinyl)aniline of formula I or a salt thereof.
The preparation of 3-Fluoro4-(4-morpholinyl)anilme of formula I or a salt thereof as described in the above process steps-(a) and (b) can be carried out by using the suitable solvents, reagents, methods, parameters and conditions as described hereinabove.
The following examples are given for the purpose of illustrating the present invention and should not be considered as limitation on the scope or spirit of the invention.

Preparation of 2-Flouroaniline hydrochloride
Methanol (300 ml) was taken into an autoclave vessel at 25-30°C, followed by the addition of l-flouro-2-nitrobenzene (100 g), Raney nickel (12 g) and aqueous ammonia solution (15 ml) at the same temperature. The reaction mixture was hydrogenated under a pressure of 5 Kg/cm2 at 25-30°C for about 5 to 6 hours. The temperature of the reaction mass increased to 45-50°C. After completion of the reaction, the resulting mass was cooled to 25-30°C. The reaction mixture was filtered through hyflow and then washed with methanol (100 ml). Concentrated hydrochloric acid (93 ml) was added to the resulting filtrate and then the solvent was distilled off at 95-100cC to produce 105 g of 2-flouroaniline hydrochloride as a brown colour solid. FT-IR Bands (Liquid Neat): 3376,1631, 1505,1155,1026 and 923 cm"1.
Example 2 Preparation of 2,2'-[(2-Fluorophenyl)imino]bis[ethanoI] Method-(A):
Water (200 ml) was taken into a reaction flask at 25-30°C, followed by the addition of 2-flouroaniline hydrochloride (105 g), calcium carbonate (191.6 g), 2-chloroethanol (228.5 g) and potassium iodide (5g, catalytic amount) at the same temperature. The resulting mixture was heated to reflux temperature and then maintained for 72 hours at the same temperature. After completion of the reaction, the reaction mass was cooled to 25-30°C, and then extracted five times with n-butyl acetate (300 ml x 5). The resulting organic layers were combined and the solvent was distilled off completely under reduced pressure of 5 mm/Hg at 90-95°C to give 140 g of 2,2'-[(2-fluorophenyl)imino]bis[ethanol] as a dark brown thick syrup.
Mass [M+H]: 200.1; FT-IR Bands (Liquid Neat): 3351,1612, 1505, 1195,1042 and 750 cm"1.

Jvietnoq-B:
Water (200 ml) was taken into a reaction flask at 25-30°C, followed by the addition of 2-fiouroaniline hydrochloride (105 g), calcium carbonate (191.6 g), 2-chloroethanol (228.5 g) and potassium bromide (5g., catalytic amount, 5%) at the same temperature. The resulting mixture was heated to reflux temperature and then maintained for 72 hours at the same temperature. After completion of the reaction the reaction mass was cooled to 25-30°C, and then extracted five times with n-butyl acetate (300 ml x 5). The resulting organic layers were combined and the solvent was distilled off completely under reduced pressure of 5 mm/Hg at 90-95°C to give 140 g of 2,2'-[(2-fluorophenyl)imino]bis[ethanol] as a dark brown thick syrup.
Mass [M+H]: 200.1; FT-IR Bands (Liquid Neat): 3351,1612, 1505, 1195,1042 and 750 cm"1.
Method-C:
2-Chloroethanol (200 ml) was taken into a reaction flask at 25-30°C, followed by the addition of 2-flouroaniline (100 g), calcium hydroxide (84 g), and potassium bromide (5g, catalytic amount, 5%) at the same temperature. The resulting mixture was heated to 110°C and then maintained for 24 hours at the same temperature. After completion of the reaction the reaction mass was cooled to 100°C and then water (300 ml) was added. The resulting mass was extracted three times with n-butyl acetate (100 ml x 3). The resulting organic layers were combined and the solvent was distilled off completely under reduced pressure of 5 mm/Hg at 90-95°C to give 190 g of 2,2'-[(2-fluorophenyl)imino]bis[ethanol] as a dark brown thick syrup. Purity by GC: 90%.
Example 3 Preparation of 4-(2-FIuorophenyl)morpho]ine
2,2'-[(2-Fluorophenyl)imino]bis[ethanol] (100 g) was added to concentrated sulphuric acid (110 ml) at 35 °C. The reaction mass was heated to 150-155°C and maintained for 1 hour at the same temperature. After the completion of the reaction, the reaction mass was cooled to 25-3 0°C, and poured into water (800 ml) followed by adjusting the pH to 11 with 50% NaOH solution (220 ml). The aqueous layer was extracted three times with butyl acetate

(250 ml x 4). The combined organic layers were washed with water (250 ml) and brine
solution (350 ml). The solvent was distilled off completely under reduced pressure of 5
mm/Hg at 90-95cC to produce 65 g of 4-(2-fluorophenyl)morpholine as a dark brown thick
syrup.
Purity by GC: 98%.
Example 4 Preparation of 3-Fluoro-4-morpholinyl-nitrobenzene Method-(A):
4-(2-Fluorophenyl)morpholine (85 g) was dissolved in acetic acid (255 ml) while stirring at 5-10°C, followed by the addition of 98% nitric acid (32.5 g) at 5-10°C. The temperature of the reaction mass was raised to 25-30°C and then stirred for 24 hours at the same temperature. After completion of the reaction, the resulting mass was poured into ice-cold water (500 ml). The separated solid was filtered and washed with water (200 ml). To the resulting solid, ethyl acetate (150 ml) was added and then stirred for 30 minutes at 0-5°C. The separated solid was filtered, washed with chilled ethyl acetate (50 ml) and then dried at 65-70°C to produce 55 g of 3-Fluoro^-moroholinyl-nitrobenzene as a yellow solid. Melting point: 111.2°-112.4°C; Mass [M+H]: 227.1; FT-IR Bands (KBr Pellet): 2925, 1603,1515,1495,1328,1242,1121 and 948 cm'1.
Method-(B):
4-(2-Fluorophenyl)morpholine (300 g) was dissolved in acetic acid (3000 ml) while stirring at 10-15°C, followed by the addition of 98% nitric acid (115 g) at 10-15°C. The temperature of the reaction mass was raised to 25-30°C and then stirred for 24 hours at the same temperature. After completion of the reaction, the resulting mass was poured into water (3000 ml). The separated solid was filtered and washed with water (300 ml). To the resulting solid dried at 65-70°C to produce 230 g of 3-Fluoro-4-morpholinyl-nitrobenzene as a yellow solid.
Purity by HPLC: 99.9%; Melting point: 111.2°412.4°C; Mass [M+H]: 227.1; FT-IR Bands (KBr Pellet): 2925,1603,1515, 1495, 1328,1242,1121 and 948 cm"1.

Preparation of 3-FIuoro-4-(4-morphoIinyl)aniIine
Ethyl acetate (500 ml) was taken into a hydrogenation flask, followed by the addition of 3-fluoro-4-morpholinyl-nitrobenzene (50 g), 10% PoVC (0.6 g) at 25-30°C. The reaction mixture was hydrogenated under pressure of 5 Kg/cm2 at 25-30°C for about 5-6 hours. After completion of the reaction, the reaction mass was cooled to 25-30cC, the reaction mixture was filtered through hyflow and then washed with ethyl acetate (100 ml). The solvent was distilled off from the resulting filtrate under reduced pressure of 5 mm/Hg at 70-75°C to give 42 g of 3-Fluoro-4-(4-moipholinyl)aniline as a brown color solid. Melting point: 120.9°-122.5°C; Mass [M+H]: 197.1; FT-IR Bands (KBr Pellet): 3419, 3339, 1641,1514, 1448, 1373, 1272, 1162, 1109,1065, 847 and 813 cm"1.
Example 6 Preparation of3-FIuoro-4-(4-morpholinyl)aniline
Ethyl acetate (500 ml) was taken into a hydrogenation flask, followed by the addition of 3-fluoro-4-morpholinylnitrobenzene (50 g), Raney Nickel (10 g) at 25-30oC. The reaction mixture was hydrogenated under pressure of 5 Kg/cm2 at 30-35°C for about 4-5 hours. After completion of the reaction, the reaction mass was cooled to 25-30°C, the reaction mixture was filtered through hyflow and then washed with ethyl acetate (50 ml). The solvent was distilled off from the resulting filtrate under reduced pressure of 5 mm/Hg at 70-75°C to give 41 g of 3-Fluoro-4-(4-morpholinyl)aniline as a brown color solid. Melting point: 121.2°-122.4°C; Mass [M+H]: 197.1; FT-IR Bands (KBr Pellet): 3419, 3339,1641,1514, 1448, 1373, 1272, 1162,1109,1065, 847 and 813 cm"1.
Example 7 Preparation of 3-FIuoro-4-(4-morpholinyl)aniIine
Water (250 ml) was added to 3-fluoro-4-morpholrnylnitrobenzene (50 g) in acetone (100 ml) at 25-30°C and the resulting mass was stirred for 5-10 minutes at the same temperature. To the resulting mixture, sodium dithionite (232 g) was added slowly for 2 hours at 25-30°C and maintained for 5 hours at the same temperature. After completion of

reaction, the solid obtained was filtered, washed with water (50 ml) and dried to give 31.2 g of 3-Fluoro-4-(4-morpholinyl)aniline as a brown color solid.
Melting point: 121.2°-122.4°C; Mass [M+H]: 197.1; FT-IR Bands (KBr Pellet): 3419, 3339, 1641,1514,1448, 1373,1272, 1162,1109,1065, 847 and 813 cm"1.

1. A process for the preparation of 3-Fluoro-4-(4-morpholinyl)aniline of formula I:
or a salt thereof, which comprises:
a) reducing l-fluoro-2-nitrobenzene of formula H:
with a suitable reducing agent or a hydrogenation catalyst, optionally in the presence of a base, to produce 2-fluoroanline of formula III:
or a salt thereof; b) reacting the compound of formula HI or a salt thereof with 2-haloethanol of formula IV:
wherein 'X' is a halogen;
in the presence of a suitable base, and optionally in the presence of an alkali metal
halide as a catalyst, to produce 2,2,-[(2-fluorophenyl)imino]bis[ethanoi] of formula
V:

c) reacting the compound of formula V with a suitable dehydrating agent to produce 4-(2-fluorophenyl)morpholine of formula VI:
d) reacting the compound of formula VI with a suitable nitrating agent in the presence of a suitable solvent to produce 3-fluoro-4-morpholinyl-nitrobenzene of formula VII:
and; e) reducing the compound of formula VII with a suitable reducing agent or a hydrogenation catalyst in a suitable solvent to produce 3-Fluoro-4-(4-morpholinyl) aniline of formula I or a salt thereof.
2. The process as claimed in claim 1, wherein the hydrogenation catalysts used in step-fa) include, but are not limited to, Raney nickel, palladium on carbon, platinum oxide, platinum on carbon, Pd(OH)2, Pd-BaSC>4 and the like; wherein the reducing agent used in step-(a) include, but are not limited to, palladium on carbon and ammonium formate, palladium on carbon and hydrazine hydrate, palladium on carbon and formic acid, palladium on carbon and cyclohexadiene, sodium hydro sulphite, FeCU and ammonium chloride, FeCl} and hydrazine hydrate, iron powder and acetic acid, iron powder and HC1, Zinc dust and acetic acid, tin(II) chloride, Zinc dust and HC1, Zinc dust and ammonium formate, Zinc dust and ammonium chloride, sodium dithionite, Na2S, LiAlHU, NOBH4, and the like; wherein the solvent used in step-(a) is selected from the group consisting of methanol, ethanol, 1-propanol, isopropyl alcohol, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and mixtures thereof; wherein the inorganic base used in step-(a) is aqueous ammonia, ammonia saturated in

an organic solvent, sodium hydroxide, calcium hydroxide, magnesium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, sodium methoxide, sodium ethoxide, sodium tert-butoxide, sodium isopropoxide and potassium tert-butoxide, and the like; wherein the reaction in step-fa) is carried out at a temperature of about 20°C to the reflux temperature of the solvent used, wherein the reaction time may vary from about 3 hours to about 10 hours; wherein the reaction in step-(a) is carried out under hydrogen pressure of about 1 kg/cm2 to about 10 kg/cm2; wherein the solvent used in step-(b) is selected from the group consisting of water, methanol, ethanol, 1-propanol, isopropyl alcohol, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and mixtures thereof; the inorganic base used in step-(b) is selected from the group consisting of aqueous ammonia, ammonia saturated in an organic solvent, sodium hydroxide, calcium hydroxide, magnesium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, sodium methoxide, sodium ethoxide, sodium tert-butoxide, sodium isopropoxide and potassium tert-butoxide; wherein the catalyst used in step-(b) is selected from the group consisting of sodium bromide, sodium iodide, potassium bromide and potassium iodide; wherein the amount of the alkali metal halide employed in step-(b) is 1% w/w to about 8% w/w; wherein the reaction in step-(b) is carried out at a temperature of about 50°C to the reflux temperature of the solvent used; wherein the reaction time may vary from about 12 hours to about 75 hours; wherein the dehydrating agent used in step-(c) is include, but are not limited to, sulphuric acid, calcium Oxide, phosphorous pentoxide, phosphoryl Chloride, para-toluene sulphonic acid, camphor sulphonic acid, and the like; wherein the reaction in step-(c) is carried out at a temperature of about 30°C to about 160°C; wherein the reaction time may vary from about 30 minutes to about 3 hours; wherein the solvents used in step-(d) include, but are not limited, methanol, ethanol, 1-propanol, isopropyl alcohol, acetonitrile, N,N-dimethylformamide, acetic acid N,N-dimethylacetamide, dimethylsulfoxide, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and mixtures thereof; wherein the reaction in step-(d) is carried out at a temperature of about 0°C to 50°C; wherein the reaction time may

vary from about 5 hours to about 30 hours; wherein the hydrogenation catalysts used in step-(e) include, but are not limited to, Raney nickel, palladium on carbon, platinum oxide, platinum on carbon, Pd(OH)2, Pd-BaSC>4 and the like; wherein the reducing agents used in step-(e) include, but are not limited to, palladium on carbon and ammonium formate, palladium on carbon and hydrazine hydrate, palladium on carbon and formic acid, palladium on carbon and cyclohexadiene, sodium hydro sulphite, FeCh and ammonium chloride, FeCi3 and hydrazine hydrate, iron powder and acetic acid, iron powder and HC1, Zinc dust and acetic acid, tin(II) chloride, Zinc dust and HC1, Zinc dust and ammonium formate, Zinc dust and ammonium chloride, sodium dithionite, Na2S, L1AIH4, MBH4, and the like; wherein the solvent used in step-(e) is selected from the group consisting of methanol, ethanol, 1-propanol, isopropyl alcohol, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and mixtures thereof; wherein the reaction in step-(e) is carried out under hydrogen pressure of about 1 kg/cm2 to about 10 kg/cm2. 1. The process as claimed in claim 2; wherein the specific hydrogenation catalyst is Raney nickel; wherein the specific reducing agent used in step-(a) is sodium dithionite, palladium on carbon and cyclohexadiene, sodium hydro sulphite, FeC^ and ammonium chloride, FeCl3 and hydrazine hydrate, and iron powder and acetic acid; wherein the specific solvent used in step-(a) is methanol; wherein the most specific inorganic base used in the step-(a) is aqueous ammonia; wherein the reaction in step-fa) is carried out at a temperature of about 25°C to about 50°C; wherein the reaction in step-(a) is carried out under pressure of about 2 kg/cm2 to about 5 kg/cm2; wherein the most specific solvent used in step-(b) is water; wherein the base used in step-(b) is calcium hydroxide, sodium hydroxide, potassium hydroxide, calcium carbonate, sodium carbonate or potassium carbonate; wherein the specific alkali metal halide is potassium bromide or potassium iodide; wherein the amount of the alkali metal halide employed in step-(b) is about 3.5% w/w to about 5.5% w/w; wherein the reaction in step-(b) is carried out at a temperature of about 60°C to the reflux temperature of the solvent used; wherein the dehydrating agent used in step-(c) is sulphuric acid; wherein the reaction in step-(c) is carried out at a temperature of about 40°C to about 155°C;

wherein the reaction time may vary from about 45 minutes to about 2 hours; wherein the nitrating agent used in step-(d) is nitric acid; wherein the solvent used in step-(d) is acetic acid; wherein the reaction in step-(d) is carried out at a temperature of about 5°C to about 35°C; wherein the reaction time may vary from about 15 to about 25 hours; wherein the hydrogenation catalyst used in step-(e) is Raney nickel or palladium on carbon; wherein the reducing agent used in step-(e) is palladium on carbon and cyclohexadiene, sodium hydro sulphite, FeCLj and ammonium chloride, FeCl3 and hydrazine hydrate, and iron powder and acetic acid; wherein the solvent used is step-(e) is ethyl acetate; wherein the reaction in step-(e) is carried out under hydrogen pressure of about 2 kg/cm2 to about 5 kg/cm2.
The process as claimed in claim 3, wherein the reaction in step-(b) is carried out at the reflux temperature of the solvent used; wherein the reaction in step-(d) is carried out at a temperature of about 10°C to about 30°C. A process for the preparation of 3-Fluoro-4-(4-morpholinyl)aniline of formula I:
or a salt thereof, which comprises:
a) reacting 2-flouroaniline of formula HI:
or a salt thereof with 2-haloethanol of formula IV:
wherein 'X' is a halogen,

in the presence of a suitable base, and optionally in the presence of an alkali metal halide as a catalyst, to produce 2,2'-[(2-fluorophenyl)imino]bis[ethanol] of formula V:
b) reacting the compound of formula V with a suitable dehydrating agent to produce 4-(2-fluorophenyl)morpholine of formula VI:
c) reacting the compound of formula VI with a suitable nitrating agent in the presence of a suitable solvent to produce 3-fluoro-4-morpholinyl-nitrobenzene of formula VII:
and; d) reducing the compound of formula VII with a suitable reducing agent or a
hydrogenation catalyst in a suitable solvent to produce 3-Fluoro-4-(4-
morpholinyl)aniline of formula I or a salt thereof. The process as claimed in claim 5, wherein the solvent used in step-(a) is selected from the group consisting of water, methanol, ethanol, 1-propanol, isopropyl alcohol, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and mixtures thereof; the inorganic base used in step-(a) is selected from the group consisting of aqueous ammonia, ammonia saturated in an organic solvent, sodium hydroxide, calcium

hydroxide, magnesium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, sodium methoxide, sodium ethoxide, sodium tert-butoxide, sodium isopropoxide and potassium tert-butoxide; wherein the catalyst used in step-(a) is selected from the group consisting of sodium bromide, sodium iodide, potassium bromide and potassium iodide; wherein the amount of the alkali metal halide employed in step-(a) is 1% w/w to about 8% w/w; wherein the reaction in step-(a) is carried out at a temperature of about 50CC to the reflux temperature of the solvent used; wherein the reaction time may vary from about 12 hours to about 75 hours; wherein the dehydrating agent used in step-(b) is include, but are not limited to, sulphuric acid, calcium Oxide, phosphorous pentoxide, phosphoryl Chloride, para-toluene sulphonic acid, camphor sulphonic acid, and the like; wherein the reaction in step-(b) is carried out at a temperature of about 30°C to about 160°C; wherein the reaction time may vary from about 30 minutes to about 3 hours; wherein the solvents used in step-(c) include, but are not limited, methanol, ethanol, 1-propanol, isopropyl alcohol, acetonitrile, N,N-dimethylformamide, acetic acid N,N-dimethylacetamide, dimethylsulfoxide, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and mixtures thereof; wherein the reaction in step-(c) is carried out at a temperature of about 0°C to 50°C; wherein the reaction time may vary from about 5 hours to about 30 hours; wherein the hydrogenation catalysts used in step-(d) include, but are not limited to, Raney nickel, palladium on carbon, platinum oxide, platinum on carbon, Pd(OH)2, Pd-BaSC>4 and the like; wherein the reducing agents used in step-(d) include, but are not limited to, palladium on carbon and ammonium formate, palladium on carbon and hydrazine hydrate, palladium on carbon and formic acid, palladium on carbon and cyclohexadiene, sodium hydro sulphite, FeCk and ammonium chloride, FeCi3 and hydrazine hydrate, iron powder and acetic acid, iron powder and HC1, Zinc dust and acetic acid, tin(II) chloride, Zinc dust and HC1, Zinc dust and ammonium formate, Zinc dust and ammonium chloride, sodium dithionite, Na2S, LiAlFL^ NiBH4, and the like; wherein the solvent used in step-(d) is selected from the group consisting of methanol, ethanol, 1-propanol, isopropyl alcohol, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and

mixtures thereof; wherein the reaction in step-(d) is carried out under hydrogen pressure of about 1 kg/cm to about 10 kg/cm .
The process as claimed in claim 6; wherein the most specific solvent used in step-(a) is water; wherein the base used in step-(a) is calcium hydroxide, sodium hydroxide, potassium hydroxide, calcium carbonate, sodium carbonate or potassium carbonate; wherein the specific alkali metal halide is potassium bromide or potassium iodide; wherein the amount of the alkali metal halide employed in step-(a) is about 3.5% w/w to about 5.5% w/w; wherein the reaction in step-(a) is carried out at a temperature of about 60°C to the reflux temperature of the solvent used; wherein the dehydrating agent used in step-(b) is sulphuric acid; wherein the reaction in step-(b) is carried out at a temperature of about 40°C to about 155°C; wherein the reaction time may vary from about 45 minutes to about 2 hours; wherein the nitrating agent used in step-(c) is nitric acid; wherein the solvent used in step-(c) is acetic acid; wherein the reaction in step-(c) is carried out at a temperature of about 5°C to about 35°C; wherein the reaction time may vary from about 15 to about 25 hours; wherein the hydrogenation catalyst used in step-(d) is Raney nickel or palladium on carbon; wherein the reducing agent used in step-(d) is sodium dithionite, palladium on carbon and cyclohexadiene, sodium hydro sulphite, FeCb and ammonium chloride, FeCb and hydrazine hydrate, and iron powder and acetic acid; wherein the solvent used is step-(d) is ethyl acetate; wherein the reaction in step-(d) is carried out under hydrogen pressure of about 2 kg/cm2 to about 5 kg/cm2.
The process as claimed in claim 7, wherein the reaction in step-(a) is carried out at the reflux temperature of the solvent used; wherein the reaction in step-(c) is carried out at a temperature of about 10°C to about 30°C. A process for the preparation of 3-Fluoro-4-(4-morpholinyl)aniline of formula I:
or a salt thereof, which comprises:
a) reacting 2,2'-[(2-fluorophenyl)imino]bis[ethanol] of formula V:

with a suitable dehydrating agent to produce 4-(2-fluorophenyl)morpholine of
■formula VT:
reacting the compound of formula VI with a suitable nitrating agent in the presence of a suitable solvent to produce 3-fluoro-4-morpholinyl-nitrobenzene of formula VII:
and;
c) reducing the compound of formula VII with a suitable reducing agent or a
hydrogenation catalyst in a suitable solvent to produce 3-Fluoro-4-(4-
morpholinyl)aniline of formula I or a salt thereof. ). The process as claimed in claim 9, wherein the dehydrating agent used in step-(a) is include, but are not limited to, sulphuric acid, calcium Oxide, phosphorous pentoxide, phosphoryl Chloride, para-toluene sulphonic acid, camphor sulphonic acid, and the like; wherein the reaction in step-(a) is carried out at a temperature of about 30°C to about 160°C; wherein the reaction time may vary from about 30 minutes to about 3 hours; wherein the solvents used in step-(b) include, but are not limited, methanol, ethanol, 1-propanol, isopropyl alcohol, acetonitrile, N,N-dimethylformamide, acetic acid N,N-dimethylacetamide, dimethylsulfoxide, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and mixtures thereof; wherein the reaction in step-(b) is carried out at a temperature of about 0°C to 50°C; wherein the reaction time may

vary from about 5 hours to about 30 hours; wherein the hydrogenation catalysts used in step-(c) include, but are not limited to, Raney nickel, palladium on carbon, platinum oxide, platinum on carbon, Pd(OH)2, Pd-BaSC>4 and the like; wherein the reducing agents used in step-(c) include, but are not limited to, palladium on carbon and ammonium formate, palladium on carbon and hydrazine hydrate, palladium on carbon and formic acid, palladium on carbon and cyclohexadiene, sodium hydro sulphite, FeCl3 and ammonium chloride, FeCl3 and hydrazine hydrate, iron powder and acetic acid, iron powder and HC1, Zinc dust and acetic acid, tin(II) chloride, Zinc dust and HC1, Zinc dust and ammonium formate, Zinc dust and ammonium chloride, sodium dithionite, Na2S, LiAlH^ N1BH4, and the like; wherein the solvent used in step-(c) is selected from the group consisting of methanol, ethanol, 1-propanol, isopropyl alcohol, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and mixtures thereof; wherein the reaction in step-(c) is carried out under hydrogen
•y ry
pressure of about 1 kg/cm to about 10 kg/cm . 1. The process as claimed in claim 10; wherein the dehydrating agent used in step-(a) is sulphuric acid; wherein the reaction in step-(a) is carried out at a temperature of about 40°C to about 155°C; wherein the reaction time may vary from about 45 minutes to about 2 hours; wherein the nitrating agent used in step-(b) is nitric acid; wherein the solvent used in step-(b) is acetic acid; wherein the reaction in step-(b) is carried out at a temperature of about 5°C to about 35°C; wherein the reaction time may vary from about 15 to about 25 hours; wherein the hydrogenation catalyst used in step-(c) is Raney nickel or palladium on carbon; wherein the reducing agent used in step-(c) is sodium dithionite, palladium on carbon and cyclohexadiene, sodium hydro sulphite, FeCl3 and ammonium chloride, FeCi3 and hydrazine hydrate, and iron powder and acetic acid; wherein the solvent used is step-(c) is ethyl acetate; wherein the reaction in step-(c) is carried out under hydrogen pressure of about 2 kg/cm2'to about 5 kg/cm2.
1. The process as claimed in claim 10, wherein the reaction in step-(b) is carried out at a temperature of about 10°C to about 30°C.
2. A process for the preparation of 3-Fluoro-4-(4-morpholinyl)aniline of formula I:

or a salt thereof, which comprises:
a) reacting 4-(2-fluorophenyl)morpholine of formula VI:
with a suitable nitrating agent in the presence of a suitable solvent to produce 3-fluoro-4-morpholinyl-nitrobenzene of formula VII:
ind;
a) reducing the compound of formula VII with a suitable reducing agent or a
hydrogenation catalyst in a suitable solvent to produce 3-Fluoro-4-(4-
morpholinyl)aniline of formula I or a salt thereof, rhe process as claimed in claim 12, wherein the solvents used in step-(a) include, but ire not limited, methanol, ethanol, 1-propanol, isopropyl alcohol, acetonitrile, N,N-irmethylformamide, acetic acid N,N-dimethylacetamide, dimethylsulfoxide, ethyl icetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and mixtures thereof; wherein the reaction in step-(a) is carried out at a temperature of about 0°C to 50°C; wherein the reaction time may vary from about 5 hours to about 30 hours; wherein the tiydrogenation catalysts used in step-(b) include, but are not limited to, Raney nickel, palladium on carbon, platinum oxide, platinum on carbon, Pd(OH)2, Pd-BaSC>4 and the like; wherein the reducing agents used in step-(b) include, but are not limited to, palladium on carbon and ammonium formate, palladium on carbon and hydrazine hydrate, palladium on carbon and formic acid, palladium on carbon and ;yclohexadiene, sodium hydro sulphite, FeCl3 and ammonium chloride, FeCl3 and

hydrazine hydrate, iron powder and acetic acid, iron powder and HC1, Zinc dust and acetic acid, tin(II) chloride, Zinc dust and HC1, Zinc dust and ammonium formate, Zinc dust and ammonium chloride, sodium dithionite, Na2S, LiAlH^ NiBHU, and the like; wherein the solvent used in step-(b) is selected from the group consisting of methanol, ethanol, 1-propanol, isopropyl alcohol, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and mixtures thereof; wherein the reaction in step-(b) is carried out under hydrogen pressure of about 1 kg/cm to about 10 kg/cm2.
The process as claimed in claim 13; wherein the nitrating agent used in step-(a) is nitric acid; wherein the solvent used in step-(a) is acetic acid; wherein the reaction in step-(a) is carried out at a temperature of about 5°C to about 35°C; wherein the reaction time may vary from about 15 to about 25 hours; wherein the hydrogenation catalyst used in step-(b) is Raney nickel or palladium on carbon; wherein the reducing agent used in step-(b) is sodium dithionite, palladium on carbon and cyclohexadiene, sodium hydro sulphite, FeCl3 and ammonium chloride, FeCl; and hydrazine hydrate, and iron powder and acetic acid; wherein the solvent used is step-(b) is ethyl acetate; wherein the reaction in step -(b) is carried out under hydrogen pressure of about 2 kg/cm2 to about 5 kg/cm2.
The process as claimed in claim 14, wherein the reaction in step-(a) is carried out at a temperature of about 10°C to about 30°C.