FIELD OF INVENTION:
The present invention relates to novel polymorphic forms of 4-[3,5-bis (2-hydroxy phenyl)-lH-l,2,4-triazol-l-yl)-benzoic acid (Deferasirox) hereafter designated Deferasirox polymorphic Form C, D, E & F. This invention further relates to the process for the preparation of Deferasirox polymorphic Form A, C, D, E, F and amorphous form.
BACKGROUND OF THE INVENTION:
Deferasirox (ICL670) is a novel once-daily oral iron chelator, known chemically as 4-(3,5-bis (2-hydroxy phenyl)-lH-l, 2, 4-triazol-l-yl) benzoic acid. It is a tridentate ligand and binds iron with high affinity i.e., 2:1 ratio. The excess of Iron (metal) deposited in body tissues can cause severe damage to organs such as liver, the heart and the endocrine organs and can lead to death. Iron chelators are able to excrete the iron, deposited in the organs and thus lower the iron related morbidity and mortality.
It is approved by the United States Food and Drug Administration (USFDA) in November 2005 and it's chemical structure is represented by Formula-I.

Deferasirox and its pharmaceutically acceptable salts along with Pharmaceutical Composition are disclosed in US 6,465,504 and assigned to Novartis AG. This patent describes process for the preparation of Deferasirox wherein, Salicyloyl chloride is reacted with salicylamide at 170°C results in the formation of 2-(2-hydroxyphenyl) benz [e] [1, 3] oxazin-4-one, which is further subjected to crystallization in ethanol to give slight yellow color crystals of 2-(2-hydroxyphenyl) benz [e] [1, 3] oxazin-4-one.

It is further reacted with 4-hydrazine benzoic acid in presence of ethanol to give Deferasirox. This patent does not discloses any polymorphic forms of Deferasirox.
EPl 927591 patent application is disclosed new crystalline forms of Deferasirox along with the process for the preparation of the same. This patent describes new crystalline forms of Deferasirox such as Form A, Form B and process for the preparation thereof This patent also discloses amorphous form of Deferasirox.
The IP.com Journal (2007), 7(3A), 32 further disclosed the process for the preparation of Deferasirox Form-I along with the PXRD pattern which is similar to the Form-A as disclosed in EP 591.
We have carried out the crystallization of Deferasirox in different solvents, mixture of solvents and applying different parameters to obtain novel process for the preparation of Deferasirox polymorphic forms.
OBJECT OF THE INVENTION;
The main object of the present invention is to provide novel polymorphic forms of Deferasirox such as Deferasirox Form C, D, E and F.
Yet another object of the present invention is to provide process for the preparation of Deferasirox Form A, C, D, E, F and amorphous form.
SUMMARY OF THE INVENTION:
The main aspect of the present invention is to provide novel polymorphic forms of Deferasirox such as Form C, D, E and F.
Another aspect of the present invention is to provide novel process for the preparation of Deferasirox Form A, C, D, E, F and amorphous form.
In first aspect of the present invention is to provide a novel process for the preparation of Deferasirox Form-C comprising the steps of refluxing 2-(2-hydroxyphenyl) benz

[e] [I, 3] oxazin-4-one and 4-hydrazinobenzoic acid in a suitable solvent and isolating the Deferasirox Form- C by using a suitable solvent.
The present invention provides an alternative process for novel polymorphic form of Deferasirox form C comprising the steps of; dissolving Deferasirox in a suitable solvent followed by removal of the solvent by distillation method and recovering Deferasirox Form C.
The second aspect of the present invention is to provide a novel process for the preparation of Deferasirox Form-D comprising the steps of refluxing 2-(2-hydroxyphenyl) benz[e] [1,3] oxazin-4-one and 4-hydrazinobenzoic acid in a suitable solvent and isolating the Deferasirox Form- D by using a suitable solvent.
The present invention provides an alternative process for novel polymorphic form of Deferasirox Form D comprising the steps of; slow evaporation of a saturated solution of Deferasirox from a suitable solvent and recovering the Deferasirox Form D.
The third aspect of the present invention is to provide a novel process for the preparation of Deferasirox Form-E comprising the steps of refluxing 2-(2-hydroxyphenyl) benz[e] [1,3] oxazin-4-one and 4-hydrazinobenzoic acid in a suitable solvent and isolating the Deferasirox Form- E by using a suitable solvent.
The present invention provides an alternative process for novel polymorphic form of Deferasirox Form E comprising the steps of; fast evaporation of a saturated solution of Deferasirox from a suitable solvent and recovering the Deferasirox Form E. Another main aspect of the present invention is to provide novel process for the preparation of anhydrous Deferasirox Form-A, comprising the steps of; heating the amorphous Deferasirox between 80-120°C and recovering the Deferasirox Form-A. The present invention provides an alternative method for the preparation of anhydrous Deferasirox Form-A comprising the steps, of heating crystalline Deferasirox Form C, Form D and Form E between 80-120°C and recovering the Deferasirox Form-A.

Other aspect of the present invention is to provide novel process for the preparation of amorphous Deferasirox, comprising the steps; heating the crystalline Deferasirox or mixtures thereof at about 270°C to form a melt followed by cooling and recovering amorphous Deferasirox.
BRIEF DESCRIPTION OF THE DRAWINGS
Further description of preferred embodiments of the invention which are shown in the accompanying drawings, wherein:
Figure 1 illustrates the powder XRD pattern of Deferasirox Form-A.
Figure 2 illustrates DSC of crystalline Deferasirox Form-A.
Figure 3 illustrates TGA of crystalline Deferasirox Form-A.
Figure 4 illustrates the powder XRD pattern of Deferasirox Form-C.
Figure 5 illustrates DSC of crystalline Deferasirox Form-C.
Figure 6 illustrates TGA of crystalline Deferasirox Form -C.
Figure 7 illustrates the powder XRD pattern of Deferasirox Form-D.
Figure 8 illustrates DSC of crystalline Deferasirox Form-D.
Figure 9 illustrates TGA of crystalline Deferasirox Form-D.
Figure 10 illustrates the powder XRD pattern of Deferasirox Form-E.
Figure 11 illustrates DSC of crystalline Deferasirox Form E.
Figure 12 illustrates TGA of crystalline Deferasirox Form E.
Figure 13 illustrates the powder XRD pattern of Deferasirox Form F.
Figure 14 illustrates DSC of crystalline Deferasirox Form F. Figure 15 illustrates TGA of crystalline Deferasirox Form F.
Figure 16 illustrates the powder XRD pattern of amorphous Deferasirox.
Figure 17 illustrates DSC of amorphous Deferasirox.

DETAIL DESCRIPTION OF THE INVENTION;
The present invention relates to novel polymorphic forms of 4-(3,5-bis (2-hydroxy phenyl)-lH-l,2,4-triazol-l-yl)benzoic acid hereafter designated Deferasirox polymorphic Form C, D, E and F. The invention further relates to the novel process for the preparation of polymorphic forms of Deferasirox form A, C, D, E, F and amorphous form. The said forms differ from the other prior art polymorphs in its physical properties, spectral data and method of preparation and characterized by its X-ray powder diffraction pattern, differential scanning calorimetry (DSC) and Thermo gravimetric analysis.
Powder X-rav Diffraction fPXRD)
The said polymorphs of the present invention are characterized by their X-ray powder diffraction pattern. Thus, the X-ray diffraction patterns of said polymorphs of the invention were measured on PANalytical, X'Pert PRO powder diffractometer equipped with goniometer of 9/9 configuration and X'Celerator detector. The Cu-anode X-ray tube was operated at 40kV and 30mA. The experiments were conducted over the 29 range of 2.0°-50.0°, 0.030° step size and 50 seconds step time.
Diffrential Scanning Calorimetry (DSC)
The DSC measurements were carried out using the instrument either TA QIOOO or Mettler Toledo DSC 822e. The experiments were performed at a heating rate of 10.0°C/minute over a temperature range of 30°C-300°C purging with nitrogen at a flow rate of 50ml/minute. Thermo gravimetric analysis (TGA)
TGA was recorded on out using the instrument Mettler Toledo TGA/SDTA 851' and TAQ5000 of TA instrument. The experiments were performed at a heating rate of 10.0°C/min over a temperature range of 30°C-300°C purging with nitrogen at a flow rateof50ml/min.

Karl-Fisher
Water content was determined on Metrohm Karl-Fisher titrator (Model: 794 Basic Titrino) using pyridine free single solution (Merck, Mumbai) with sample mass between 450mg to 550mg.
Infrared spectroscopy
Fourier transform infrared (FT-IR) spectra were recorded with a Perkin-Elmer spectrum one spectrophotometer. The samples were prepared as 13mm thickness potassium bromide discs by triturating 1 to 2mg of sample with 300mg to 400mg of KBR by applying pressure of about 1000 Ibs/sq inch. Then theses discs were scanned in the spectral range of 4000 to 650 cm"' with a resolution of 4 cm"'.
Crystalline Deferasirox Form C is characterized by powder X-ray diffraction pattern as shown in Figure 4 with peaks at 10.23, 10.57, 11.70, 12.57, 14.52, 15.92, 9.88, 16.58, 17.57, 18.06, 19.92, 20.60, 21.48, 22.44, 23.90, 24.38, 25.07, 25.62, 26.64, 32.18 and 33.53 ± 0.2 9 values.
Crystalline Deferasirox Form C is further characterized by the DSC (Figure 5) with two melting endothermic peaks; first an extrapolated onset temperature ranging from 90 to 140°C attributed to desolvation which is identified with a peak at 113°C (maxima), and a second at 262''C corresponding to the melting of the product. Crystalline Deferasirox Form C is N,N-Dimethyl formamide (DMF) solvate with a DMF content of 13-18%, which is analysed by TGA as shown in Figure 6 and moisture content typically ranging from approx. 0.1 - 0.3% by weight supported by KF method. Preferably, the Deferasirox Form C is a mono-DMF solvate.
The present invention also provides the preparation of crystalline Deferasirox Form C by condensation, which is comprising the steps of refluxing 2-(2-hydroxyphenyl)benz[e][l,3]oxazin-4-one and 4-hydrazinobenzoic acid in N,N-dimethylformamide (DMF) for 1-2 hrs. The product was isolated by cooling the reaction mass at 15-20°C followed by washing with isopropyl ether.

The present invention also provides a process for tlie preparation of crystalline Deferasirox Form C, which comprising the steps of; dissolving Deferasirox in a solvent, such as N,N-dimethylformamide (DMF) at ambient temperature followed by removal of solvent by distillation and recovering the isolated Deferasirox Form C.
Crystalline Deferasirox Form D is characterized by powder X-ray diffraction pattern as shown in Figure 7 with peaks at 6.56, 6.79, 8.83, 11.75, 13.58, 15.18, 16.73, 17.90, 18.65, 19.32, 19.75, 20.16, 21.02, 22.09, 22.42, 23.65, 24.36, 25.73, 26.27, 27.34, 28.36, 29.62 and 31.23 ±0.20
Crystalline Deferasirox Form D is further characterized by the DSC (Figure 8, which shows two melting endothermic peaks; first at an extrapolated onset temperature ranging from 80 to 120°C attributed to desolvation, which is identified with a peak at 106°C (maxima), and a second at 262°C corresponding to complete melting of the product. Crystalline Deferasirox Form D is Tetrahydrofuran (THF) solvate with THF content of 13-18%, preferably 14-16% which is analyzed by TGA as shown in Figure 9 and moisture content typically ranging from approx. 0.1 - 0.3% by weight supported by KF method. Preferably, the Deferasirox Form D is mono-THF solvate.
The present invention also provides the preparation of crystalline Deferasirox Form D by condensation, which is comprising the steps of refluxing 2-(2-hydroxyphenyl)benz[e][l,3]oxazin-4-one and 4-hydrazinobenzoic acid in THF for 1-2 hrs. The product was isolated by cooling the reaction mass at 15-20°C followed by washing with isopropyl ether.
The present invention also provides the preparation of crystalline Deferasirox Form D, which comprises slow or fast evaporation of saturated solution of Deferasirox in a solvent, such as Tetrahydrofuran, at ambient temperature for several days. Deferasirox Form D may also be prepared by slurry method in THF. The crystalline product was isolated at room temperature and atmospheric pressure. Deferasirox used herein selected from group consisting of but not limited to anhydrous or hydrated form.

Crystalline Deferasirox Form E is characterized by powder X-ray diffraction pattern as shown in Figure 10 with peaks at 8.37, 9.10, 12.54, 14.90, 16.15, 16.71, 18.19, 18.97, 19.65, 20.46, 21.78,22.43, 23.05, 24.65, 25.01, 25.96, 29.19, and 29.83 ± 0.29
Crystalline Deferasirox Form E is further characterized by the DSC (Figure U), which shows 3 melting endothermic peaks; first and second at an extrapolated onset temperature ranging from 80 to 160°C attributed to desolvation, which is identified with peaks at 102°C, 143°C (maxima), and a third at 266°C corresponding to complete melting of the product. Crystalline Deferasirox Form E is Pyridine solvate with pyridine content of 17-21%, which is analyzed by TGA as shown in Figure 12 and moisture content typically ranging from approx. 0.1 - 0.3% by weight, preferably less than 0.1% by weight determined by KF method. Preferably, the Deferasirox Form E is mono-Pyridine solvate.
The present invention also provides the preparation of crystalline Deferasirox Form E by condensation, which is comprising the steps of refluxing 2-(2-hydroxyphenyl)benz[e][l,3]oxazin-4-one and 4-hydrazinobenzoic acid in pyridine for 1-2 hrs. The product was isolated by cooling the reaction mass at 15-20°C followed by washing with isopropyl ether.
The present invention also provides the preparation of crystalline Deferasirox Form E, which comprises slow or fast evaporation of saturated solution of Deferasirox in a solvent, such as Pyridine at ambient temperature for several days. Deferasirox Form E may also be prepared by slurry method in Pyridine. The crystalline product was isolated at room temperature and atmospheric pressure. Deferasirox used herein selected from group consisting of but not limited to anhydrous or hydrated form.
Deferasirox Form F is characterized by powder X-ray diffraction pattern as shown in Figure 13 with peaks at 10.06, 10.49, 11.97, 13.47, 13.81, 15.32, 15.63, 17.44, 18.02, 19.22,20.12, 20.34, 22.07, 22.69, 24.80,25.14, 25.79, 26.67 and 27.84 ± 0.29 values.
Crystalline Deferasirox Form F is further characterized by the DSC (Figure 14, which shows 2 melting endothermic peaks; first at an extrapolated onset temperature ranging from 30 to 80°C attributed to loss of water, which is identified with peaks at 39°C

(maxima), and a second at 266°C corresponding to complete melting of the product. Crystalline Deferasirox Form F has a water content of typically ranging approx. 3-8% by weight, preferably 4-6%, which is analyzed by TGA as shown in Figure 15 and moisture content of 4-6% by weight determined by KF method. Preferably, the Deferasirox Form F is mono-hydrate.
In another aspect, the present invention also provides a process for preparation of crystalline Deferasirox Form F comprising the steps of slurrying amorphous Deferasirox in water for several days.
Crystalline Deferasirox Form A is characterized by powder X-ray diffraction pattern with peaks at 6.60, 10.08,10.61, 12.28, 13.22, 13.56, 14.14, 15.44, 16.31, 16.64.17.46, 17.80, 18.97, 19.39, 19.87, 20.46, 21.09, 22.55, 23.19, 23.96, 25.18, 25.71, 26.25, 27.73,28.41, 29.51, 31.19, 33.39 and 36.32 ± 0.20 values as shown in Figure 1.
Another main aspect of the present invention is to provide novel process for the preparation of Form A comprising the steps of, contacting Deferasirox in a suitable solvent selected from the group comprising of lower aliphatic alcohols, ethers, lower aliphatic ketones, esters, lower aliphatic acids, aprotic polar solvents or mixtures thereof, using the methods such as slurry or anti-solvent method or by removal of solvent, followed by filtration and drying under vacuum at 50-60°C gives Deferasirox Form A. The crystallization solvents are selected from methanol, ethanol, ethyl acetate, 1,4-dioxane, nitromethane, acetone, dimethylsulphoxide, l-methyl-2-pyrrolidinone, 2-methoxyethanol, water and mixtures thereof
The present invention also provides another process for the preparation of Crystalline Deferasirox Form A comprising the steps of; spray drying the solution of Deferasirox in a solvent wherein the solvent is selected from methanol, ethanol, acetone, ethyl acetate, water and mixture thereof, preferably water, methanol, ethyl acetate or mixtures thereof gives Deferasirox Form A.
Anhydrous Deferasirox Form A is further characterized by DSC with an endothermic peak at 262°C corresponding to melting of the product as shown in Figure 2. TGA of

Deferasirox Form A shows no significant weight loss (<1%) as shown in Figure 3 further confirms it as anhydrate form. (The water content determined by the Karl-Fisher method is 0.3 to 1.0 %)
Yet another aspect of the present invention is to provide a novel process for the preparation of amorphous form of Deferasirox comprising the steps of, heating the Deferasirox followed by slow cooling and isolating Deferasirox amorphous form.
Amorphous Deferasirox is characterized by powder X-ray diffraction pattern as shown in Figure 16.
Amorphous Deferasirox is further characterized by DSC with a weak glass transition in the range 105-110°C with a glass transition onset temperature (Tg) at 107°C followed by a exothermic peak at an extrapolated onset temperature ranging from 130 to 170°C, corresponding to the transition from amorphous phase to an crystalline phase which is identified with a peak at 152°C, and a second endothermal peak at 263°C (maxima), corresponding to the complete melting of the product as shown in Figure 17. (The water content determined by the Karl-Fisher method is 1 to 2.0 %)
In the foregoing section embodiments are described by way of examples to illustrate the process of invention. However, these are not intended in any way to limit the scope of the present invention and several variants of these examples would be evident to person ordinary skilled in the art.

PREPARATION OF DEFERASIROX FORM C
Example 1:
5g of 2-(2-hydroxyphenyl)benz[e][l,3]oxazin-4-one and 3.6g of 4-hydrazinobenzoic acid are dissolved in DMF (50 ml) and stirred for 10 minutes at 25-30°C. The clear solution was refluxed for 1-2 hrs at 150-155°C. After the completion of reaction (as per the TLC) the solvent was removed by vacuum distillation at 60-70°C. The precipitated product was isolated and washed with 10 ml of isopropyl ether. The solid product obtained is identified as crystalline Deferasirox Form C XRD of wet sample showed it to be Form C
Example 2:
5g of Deferasirox is dissolved in DMF (5 ml) at 25-30°C and stirred for 10 minutes. The resulting clear solution is distilled out completely under vacuum at 60-65°C. The solid obtained is identified as crystalline Deferasirox Form C XRD of wet sample showed it to be Form C
PREPARATION OF DEFERASIROX FORM D
Example 3:
5g of 2-(2-hydroxyphenyl)benz[e][l,3]oxazin-4-one and 3.6g of 4-hydrazinobenzoic acid are suspended in THF (50 ml) and stirred for 10 minutes at 25-30°C. The suspension is refluxed for 1-2 hrs at 65-70°C. After the completion of reaction a clear solution is obtained. Then half the volume of solvent was removed by vacuum distillation at 40-45°C. The slurry obtained was stirred for 30 min at 15-20°C. The precipitated product was isolated by filtration and washed with 10 ml of isopropyl ether. The solid obtained is identified as crystalline Deferasirox Form D. XRD of wet sample showed it to be Form D
Example 4:
5g of Deferasirox is suspended in Tetrahydrofuran (15 ml) at 25-30°C and stirred for 10 minutes. The resulting slurry is heated to 70-80°C and stirred for 10 min at same temperature. Filter the hot solution through cotton to remove any undissolved solid particulate. The clear solution obtained is then transferred to a conical flask and

evaporate the solvent slowly at ambient temperature. Solid obtained was filtered and identified as crystalline Deferasirox Form D. XRD of wet sample showed it to be Form D
PREPARATION OF DEFERASIROX FORM E
Example 5:
5g of 2-(2-hydroxyphenyl)benz[e][l,3]oxazin-4-one and 3.6g of 4-hydrazinobenzoic acid are dissolved in pyridine (50 ml) and stirred for 10 minutes at 25-30°C. The clear solution is refluxed for 1-2 hrs at 115-120°C. After the completion of reaction as per the TLC, half the volume of solvent was removed by vacuum distillation at 40-45°C. The slurry obtained was stirred for 30 min at 15-20°C. The precipitated product was isolated by filtration and washed with 10 ml of isopropyl ether. The solid obtained is identified as crystalline Deferasirox Form E XRD of wet sample showed it to be Form E
Example 6:
5g of Deferasirox is suspended in Pyridine (5 ml) at 25-30°C and stirred for 10 minutes. The clear solution obtained is then transferred to a Petri dish and evaporate the solvent rapidly at ambient temperature. Solid obtained was filtered and identified as crystalline Deferasirox Form E. XRD of wet sample showed it to be Form E
PREPARATION OF AMORPHOUS DEFERASIROX
Example 7:
_5g of Deferasirox amorphous was prepared by holding the crystalline Deferasirox Form A at about 270°C for about 5-10 minutes. The resulting melt was slowly cooled to 25-30°C. The isolated solid was identified as amorphous Deferasirox.
PREPARATION OF DEFERASIROX FORM F
Example 8:


suspended in water (15ml) and the resulting slurry was stirred for 48 hours at ambient temperature. The resulting solid was identified as Deferasirox Form F.
PREPARATION OF DEFERASIROX FORM A
Example 9:
2g of crystalline Deferasirox was kept in a vacuum oven dryer and heated at 80-120°C under vacuum for 24 hrs. The isolated solid was identified as crystalline Deferasirox Form A.
Example 10:
2g of amorphous Deferasirox was kept in a vacuum oven dryer and heated at 120°C under vacuum for Ihr. The isolated solid was identified as crystalline Deferasirox Form A.
Example 11
2g of crystalline Deferasirox Form F was kept in a vacuum oven dryer and heated at 80-120°C under vacuum for 24 hrs. The isolated solid was identified as crystalline Deferasirox Form A.
Example 12
5g of crystalline Deferasirox was suspended in a mixture of 5% water and methanol (350 ml) at ambient temperature. The resulting solution was slowly heated to 65-70°C for 30 min to get clear solution which was subjected to spray drying in a mini spray dryer (model Buchi - 290) at a temperature of 80-90°C using nitrogen gas. The isolated solid was identified as crystalline Deferasirox Form A.
Example 13
5g of crystalline Deferasirox was" suspended in ethyl acetate (300 ml) at ambient temperature. The resulting solution was slowly heated to 78-80°C for 30 min to get clear solution which was subjected to spray drying in a mini spray dryer (model Buchi - 290) at a temperature of 80-90°C using nitrogen gas. The isolated solid was identified as crystalline Deferasirox Form A.

We Claims:
1. A crystalline Deferasirox Form-C.
2. The crystalline Deferasirox Form-C according to claim 1, wherein the crystalline Form C exhibits an X-ray powder diffraction pattern having characteristic peaks expressed in degrees 20 at 9.88, 10.23, 10.57, 11.70, 12.57, 14.52, 15.92, 9.88, 16.58, 17.57, 18.06, 19.92, 20.60, 21.48, 22.44, 23.90, 24.38, 25.07, 25.62, 26.64, 32.18 and 33.53 ± 0.2 9 values.
3. The crystalline Deferasirox Form-C according to claim 1, wherein said crystalline Form C is a mono dimethylformamide (DMF) solvate of Defrasirox containing 13-18 % of dimethylformamide.
4. The process for the preparation of crystalline Deferasirox Form C, comprising the steps of;

a) reacting 2-(2-hydroxyphenyl)benz[e][l,3]oxazin-4-one and 4-hydrazino -benzoic acid in N, N-dimethylformamide at reflux,
b) cooling the reaction mass and
c) isolating the Deferasirox Form-C.
5. The process for the preparation of crystalline Deferasirox Form C, comprising
the steps of;
a) dissolving Deferasirox in N, N-dimethylformamide,
b) removing the solvent and
c) isolating Deferasirox Form C.

6. The process for the preparation of crystalline Deferasirox Form C according to claim 5b, wherein the solvent is removed by distillation.
7. A Crystalline Deferasirox Form-D.
8. A Crystalline Deferasirox Form-D according to claim 8, wherein crystalline Form-D is having the PXRD peaks at 6.56, 6.79, 8.83, 11.75, 13.58, 15.18,

16.73, 17.90, 18.65, 19.32, 19.75, 20.16, 21.02, 22.09, 22.42, 23.65, 24.36, 25.73, 26.27, 27.34, 28.36, 29.62 and 31.23 ± 0.20 values.
9. The crystalline Deferasirox Form-D according to claim 7, wherein the said crystalline form D is a mono tetrahydrofuran (THF) solvate containing 13-18 % of tetrahydrofuran.
10. The process for the preparation of crystalline Deferasirox Form D comprising the steps of

a) reacting 2-(2-hydroxyphenyl)benz[e][l,3]oxazin-4-one and 4-hydrazino -benzoic acid in N, N-dimethylformamide at reflux,
b) cooling the reaction mass and
c) isolating the crystalline Form D.
11. The process for the preparation of crystalline Deferasirox Form D, comprising
the steps of;
a) dissolving Deferasirox in tetrahydrofuran,
b) removing the solvent and
c) isolating the crystalline Deferasirox Form-D

12. The process according to claim 1 lb, wherein the solvent is removed by slow evaporation or fast evaporation.
13. A Crystalline Deferasirox Form-E.
14. A Crystalline Deferasirox Form-E according to claim 14, wherein the crystalline Form E is having the PXRD peaks at 8.37, 9.10, 12.54, 14.90, 16.15, 16.71, 18.19, 18.97, 19.65, 20.46, 21.78, 22.43, 23.05, 24.65, 25.01, 25.96,29.19, and 29.83 ± 0.28 values
15. The crystalline Deferasirox Form-E according to claim 13, wherein said crystalline Form E is a mono pyridine solvate containing 16-21 % of pyridine.
16. The process for the preparation of crystalline Deferasirox Form E, comprising the steps of;

a) reacting 2-(2-hydroxyphenyl)benz[e][l,3]oxazin-4-one and 4-
hydrazino benzoic acid in pyridine at reflux,
b) cooling the reaction mass and
c) isolating the crystalline Deferasirox Form E.
17. The process for the preparation of crystalline Deferasirox Form E comprising
the steps of;
a) dissolving Deferasirox in pyridine,
b) removing the solvent and
c) isolating crystalline Deferasirox Form E.

18. The process according to claim 17b, wherein the solvent is removed by slow evaporation or fast evaporation.
19. A Crystalline Deferasirox Form-F.
20. A Crystalline Deferasirox Form-F according to claim 21, wherein the crystalline Deferasirox is having the PXRD peaks at 10.06, 10.49, 11.97, 13.47, 13.81, 15.32, 15.63, 17.44, 18.02, 19.22, 20.12, 20.34, 22.07, 22.69, 24.80, 25.14, 25.79, 26.67 and 27.84 ± 0.26 values.
21. The crystalline Deferasirox Form-F according to claim 19, wherein said crystalline Form F is a mono hydrate containing 3-8 % of water.
22. The process for the preparation of crystalline Deferasirox Form F, comprising the steps of;

a) suspending amorphous Deferasirox in water,
b) stirring the resulting step a) and
c) Isolating the Deferasirox Form F
23. Process for the preparation of crystalline Deferasirox Form A comprising the
steps of;
a) heating either amorphous or crystalline Deferasirox and
b) isolating the crystalline Deferasirox Form A.

24. Process for the preparation of crystalline Deferasirox Form A according to
claim 23a, wherein the Deferasirox is heated to a temperature between 80-
120° C
25. Process for the preparation of crystalline Deferasirox Form A which
comprising the steps of;
a) suspending crystalline Deferasirox in a solvent,
b) removing the solvent and
c) isolating crystalline Deferasirox Form A
26. Process for the preparation of crystalline Deferasirox Form A according to
claim 25a, wherein the solvent group is selected from polar solvents, lower
aliphatic alcohols, chlorinated solvents, esters, lower aliphatic ketones, water
or mixtures thereof,
27. Process for the preparation of crystalline Deferasirox Form A according to
claim 26, wherin the said solvent is selected are preferably, methanol,
dichloromethane, ethyl acetate, acetone, water and mixtures thereof
28. Process according to claim 25b, wherein the solvent is removed by techniques
such as spray drying, freeze drying.