FIELD OF THE INVENTION
The present invention relates to the process for the preparation of novel solid forms of Abemaciclib (1). It further relates novel crystalline form 1, form 2, form 3, form 4, form 5, form 6, form 7 , form 8, form 9 , form 10 , form 11 , form 12 and amorphous form of Abemaciclib (1), having purity more than 99.0% (w/w) by HPLC.
BACKGROUND OF THE INVENTION
Abemaciclib (1) is a kinase inhibitor for oral administration drug for the treatment of advanced or metastatic breast cancers. It was developed by Eli Lilly. On 28 September 2017, it was approved for use in the United States by the FDA for the treatment of certain breast cancers. Chemically it is known N-[5-[(4-Ethyl-l-piperazinyl) methyl]-2-pyridinyl]-5-fluoro-4-[4-fluoro-2-methyl-l-(l-methylethyl)-lH-benzimidazol-6-yl]-2-pyrimidinamine.
Synthesis of polymorphic forms of Abemaciclib (1) has been reported in few patents and non-patents. The contents of which are hereby incorporated as reference in their entirety.
US7855211 patent discloses crystalline forms I and III of Abemaciclib and the process for preparing crystalline form I.
WO2017108781 application discloses form I and form IV of Abemaciclib.
WO2017211268 application discloses crystalline form A, form B, and form C of Abemaciclib.
WO2019102492 application discloses crystalline forms Ml to M5 of Abemaciclib and their process. It also discusses process for the preparation of Abemaciclib.
Still there lies the need for synthesizing newer forms of Abemaciclib, with better physiochemical properties, so that ideal formulation requirements are met. Hence, the

present inventors hereby, disclose novel forms of Abemaciclib and the process for preparing the same.
OBJECTIVE OF THE INVENTION
Accordingly, in one object the present invention provides process for the preparation novel solid forms of Abemaciclib (1).
In another object, the present invention provides a process for the preparation of solid forms of Abemaciclib (1), which may comprise of crystalline form 1, form 2, form 3, form 4, form 5, form 6, form 7 , form 8, form 9 , form 10 , form 11 , form 12 and amorphous form of Abemaciclib (1)
In another object, the present invention provides solid forms of Abemaciclib (1), which may comprise of crystalline forms and amorphous form having purity more than 99.0% (w/w) by High-performance liquid chromatography (HPLC).
SUMMARY OF THE INVENTION
Accordingly, in one aspect the present invention provides process for the preparation solid forms of Abemaciclib (1).
In another aspect, the present invention provides solid forms of Abemaciclib (1), which may comprise of crystalline form 1, form 2, form 3, form 4, form 5, form 6, form 7 , form 8, form 9 , form 10 , form 11 , form 12 and amorphous form of Abemaciclib (1).
In another aspect the present invention provides solid forms of Abemaciclib (1), which may comprise of crystalline forms and amorphous form having purity more than 99.0% (w/w) by HPLC.
In another aspect, the present invention provides process for the preparation of form 1 and form 2 of Abemaciclib (1), comprising:
a) providing s solution of Abemaciclib (1) in a suitable solvent;
b) heating the reaction mass to a suitable temperature;
c) cooling the reaction mass to a suitable temperature; and

d) isolating crystalline form of Abemaciclib (1).
In some aspect, crystalline form 1 and form 2 of Abemaciclib (1) may be prepared by providing a solution of Abemaciclib (1) in a suitable solvents and heating to a temperature of 30-80 °C, preferably 30-40 °C in some cases and 65-70 °C in other cases and then cooling the reaction mixture to 0-15 °C, preferably 0-5 °C. The obtained solid was isolated using a suitable technique to yield crystalline form 1 and form 2 of Abemaciclib (1).
In another aspect the present invention provides process for the preparation of crystalline form 3, form 5, form 6, form 7 form 8 and form 9 of Abemaciclib (1), comprising:
a) providing a solution of Abemaciclib (1) in a mixture of suitable solvents;
b) heating the reaction mass to a suitable temperature;
c) cooling the reaction mass to a suitable temperature; and
d) isolating suitable crystalline forms of Abemaciclib (1) using a suitable technique.
In some aspect, crystalline form 3, form 5, form 6, form 7, form 8 and form 9 of Abemaciclib (1) may be prepared by providing a solution of Abemaciclib (1) in a mixture of suitable solvents. In another embodiment, the crystalline forms were obtained by heating the reaction mixture to a temperature of 30-90 °C, preferably 40-80 °C and then cooled to 0-15 °C, preferably 0-5 °C. Finally, the solid was isolated dried using a suitable technique to obtain crystalline form 5, 6, 7, 8 and 9 of Abemaciclib (1).
In another aspect the present invention provides process for the preparation of form 4 of Abemaciclib (1), comprising:
a) providing a solution of Abemaciclib (1) in a mixture of suitable solvents;
b) heating the reaction mass to a suitable temperature;
c) cooling the reaction mass to a suitable temperature; and

d) isolating Abemaciclib (1) using a suitable technique to yield form 4 of Abemaciclib (1). In some embodiment, crystalline form 4 of Abemaciclib (1) may be prepared by providing a solution of Abemaciclib (1) in a mixture of suitable solvents. In another embodiment, the crystalline forms were obtained by heating the reaction mixture to a temperature of 30-90 °C, preferably 40-80 °C and then cooled to 0-15 °C, preferably 0-5 °C. Finally, the isolated solid was dried using a suitable technique to obtain crystalline form 5, 6, 7, 8 and 9 of Abemaciclib (1).
In another aspect the present invention provides process for the preparation of crystalline form 10, form 11 and form 12 of Abemaciclib (1), comprising:
a) providing form 4 of Abemaciclib (1); and
b) isolating crystalline form of Abemaciclib (1) using a suitable technique.
In another embodiment, Abemaciclib (1) may be dissolved in a mixture of solvents and heated to a temperature of 40-80 °C, preferably 65-70 °C. The reaction mixture was cooled to 0-15 °C, preferably 0-5 °C and isolated using a suitable drying technique to form 10 of Abemaciclib (1).
In another aspect the present invention provides process for the preparation of amorphous form of Abemaciclib (1), comprising:
a) providing s solution of Abemaciclib (1) in a mixture of suitable solvents;
b) heating the reaction mass to a suitable temperature;
c) adding hot Abemaciclib (1) solution to a mixture of solvents at a suitable temperature; and
d) isolating amorphous form of Abemaciclib (1) using a suitable technique.
In yet another embodiment, Abemaciclib (1) may be dissolved in a mixture of solvents and heated to a temperature of 40-80 °C, preferably 55-60 °C. The reaction mixture so obtained was then added to a mixture of solvents and cooled to 0-15 °C, preferably 0-

5 °C and isolated using a suitable technique to yield amorphous form of Abemaciclib CD-BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 illustrates X-Ray Diffraction (XRD) pattern of crystalline form 1 of Abemaciclib (1).
Figure 2 illustrates X-Ray Diffraction (XRD) pattern of crystalline form 2 of Abemaciclib (1).
Figure 3 illustrates X-Ray Diffraction (XRD) pattern of crystalline form 3 of Abemaciclib (1).
Figure 4 illustrates X-Ray Diffraction (XRD) pattern of crystalline form 4 of Abemaciclib (1).
Figure 5 illustrates X-Ray Diffraction (XRD) pattern of crystalline form 5 of Abemaciclib (1).
Figure 6 illustrates X-Ray Diffraction (XRD) pattern of crystalline form 6 of Abemaciclib (1).
Figure 7 illustrates X-Ray Diffraction (XRD) pattern of crystalline form 7 of Abemaciclib (1).
Figure 8 illustrates X-Ray Diffraction (XRD) pattern of crystalline form 8 of Abemaciclib (1).
Figure 9 illustrates X-Ray Diffraction (XRD) pattern of crystalline form 9 of Abemaciclib (1).
Figure 10 illustrates X-Ray Diffraction (XRD) pattern of crystalline form 10 of Abemaciclib (1).
Figure 11 illustrates X-Ray Diffraction (XRD) pattern of crystalline form 11 of Abemaciclib (1).
Figure 12 illustrates X-Ray Diffraction (XRD) pattern of crystalline form 12 of Abemaciclib (1).
Figure 13 illustrates X-Ray Diffraction (XRD) pattern of amorphous form of Abemaciclib (1).

DETAILED DESCRIPTION OF THE INVENTION
Accordingly, in one embodiment the present invention provides process for the preparation solid forms of Abemaciclib (1).
In another embodiment the present invention provides solid forms of Abemaciclib (1), which may comprise of crystalline form 1, form 2, form 3, form 4, form 5 form 6, form 7, form 8 , form 9, form 10 , form 11 , form 12 and amorphous form of Abemaciclib (1).
In another embodiment the present invention provides solid forms of Abemaciclib (1), which may comprise of crystalline forms and amorphous form having purity more than 99.0% (w/w) by HPLC.
In another embodiment the present invention provides process for the preparation of form 1 and form 2 of Abemaciclib (1), comprising:
a) providing s solution of Abemaciclib (1) in a suitable solvent;
b) heating the reaction mass to a suitable temperature;
c) cooling the reaction mass to a suitable temperature; and
d) isolating the crystalline form of Abemaciclib (1).
In some embodiment, crystalline form 1 and form 2 of Abemaciclib (1) may be prepared by providing a solution of Abemaciclib (1) in a suitable solvents and heating to a temperature of 30-80 °C, and then cooled to 0-15 °C, preferably 0-5 °C and isolated to yield crystalline form 1 and form 2 of Abemaciclib (1)
In another embodiment the present invention provides process for the preparation of crystalline form 3, form 5, form 6, form 7, form 8, form 9 of Abemaciclib (1), comprising:
a) providing a solution of Abemaciclib (1) in a mixture of suitable solvents;
b) heating the reaction mass to a suitable temperature;
c) cooling the reaction mass to a suitable temperature; and

d) isolating crystalline form of Abemaciclib (1) using a suitable technique.
In some embodiment, crystalline form 3, form 5, form 6, form 7, form 8, form 9 of Abemaciclib (1) may be prepared by providing a solution of Abemaciclib (1) in a mixture of suitable solvents and heating to a temperature of 30-90 °C, preferably 40-80 °C and then cooled to 0-15 °C, preferably 0-5 °C and isolated to yield crystalline form crystalline form 3, form 5, form 6, form 7, form 8, form 9 of Abemaciclib (1).
In another embodiment the present invention provides process for the preparation of form 4 of Abemaciclib (1), comprising:
a) providing s solution of Abemaciclib (1) in a mixture of suitable solvents;
b) heating the reaction mass to a suitable temperature;
c) cooling the reaction mass to a suitable temperature; and
d) isolating Abemaciclib (1) using a suitable technique to yield crystalline form 4 of Abemaciclib (1).
In yet another embodiment, Abemaciclib (1) may be dissolved in a mixture of solvents and heated to a temperature of 40-80 °C, preferably 65-70 °C. The reaction mixture was cooled to 0-15 °C, preferably 0-5 °C and isolated to form 4 of Abemaciclib (1).
In another embodiment the present invention provides process for the preparation of form 10, form 11 and form 12 of Abemaciclib (1), comprising:
a) providing form 4 of Abemaciclib (1); and
b) isolating crystalline form of Abemaciclib (1) using a suitable technique.
In yet another embodiment, Abemaciclib (1) may be dissolved in a mixture of solvents and heated to a temperature of 40-80 °C, preferably 65-70 °C. The reaction mixture was cooled to 0-15 °C, preferably 0-5 °C and isolated using a suitable technique to form 10, form 11 and form 12 of Abemaciclib (l).The suitable technique may be selected from a group comprising of but not restricted to drying, grinding, blending in a mortar pestle, applying pressure using hydraulic pressure instrument or the like.

In another embodiment the present invention provides process for the preparation of amorphous form of Abemaciclib (1), comprising:
a) providing s solution of Abemaciclib (1) in a mixture of suitable solvents;
b) heating the reaction mass to a suitable temperature;
c) adding hot Abemaciclib (1) solution to a mixture of solvents at a suitable temperature; and
d) isolating amorphous form of Abemaciclib (1) using a suitable technique.
In yet another embodiment, Abemaciclib (1) may be dissolved in a mixture of solvents and heated to a temperature of 40-80 °C, preferably 55-60 °C. The reaction mixture so obtained was then added to a second solvent and cooled to 0-15 °C, preferably 0-5 °C and isolated to yield amorphous form of Abemaciclib (1).
In another embodiment, the present invention provides solid forms of Abemaciclib (1) prepared herein is having purity more than 99.0% by HPLC.
In another embodiment, the suitable solvents used in the present invention may be selected from a group comprising of protic, aprotic solvents or mixtures thereof. The protic solvents may be selected from a group comprising of water, methanol, ethanol, isopropyl alcohol, isobutyl alcohol, dimethyl sulfoxide, or the like, preferably water and methanol were used in the present invention ; the aprotic solvents may be selected from a group comprising of acetone, acetonitrile, nitromethane, 1,4-dioxane, diethyl ether, dichloromethane, ethyl acetate, N-butyl acetate ,N, N-dimethylformamide, methyl tertiary butyl ether, hexane, cyclohexane, toluene, tetrahydrofuran ,heptane or the like, preferably N-butyl acetate , dichloromethane , tetrahydrofuran , acetonitrile, methyl tertiary butyl ether, acetone, ethyl acetate , heptane , water, were used in the present invention.
In another embodiment, the suitable drying techniques used herein may be selected from a group comprising of solvent evaporation, distillation, lyophilization or freeze drying, spray drying, agitated thin film drying (ATFD), air tray drying (ATD), cooling the

solvent, adding anti-solvent to the reaction mixture and combination thereof. Preferably solvent evaporation by distillation and air tray drying (ATD) were used in the present invention.
In another embodiment, crystalline form 1 of Abemaciclib (1) obtained may be characterized by the XRD pattern as shown in figure 1 and having 2(6) theta values of 3.92, 4.32,10.96, 11.37, 12.71, 13.69, 14.72, 16.16, 17.00, 18.55, 19.61, 21.03, 22.23, 22.97, 23.91, 25.68, 26.94, 28.53 and 29.80 ± 0.5°
In another embodiment, crystalline form 2 of Abemaciclib (1) obtained may be characterized by the XRD pattern as shown in figure 2 and having 2(0) theta values of 4.41, 10.03, 12.08, 12.95,14.59,16.11, 17.18, 18.30,20.63,22.31,25.68,26.60,28.80, 25.19, 21.79 ±0.5°.
In another embodiment, crystalline form 3 of Abemaciclib (1) obtained may be characterized by the XRD pattern as shown in figure 3 and having 2(0) theta values of 2.61, 4.10, 8.13, 10.59, 11.68, 13.96, 14.88, 16.48, 17.14, 20.38, 21.26, 22.87, 24.20, 27.38, 28.53, 30.81, 32.42, 35.81, 36.63 and 40.89 ± 0.5°
In another embodiment, crystalline form 4 of Abemaciclib (1) obtained may be characterized by the XRD pattern as shown in figure 4 and having 2(0) theta values of 4.65, 4.97, 6.27, 6.91, 9.13, 10.12, 10.92, 12.98, 13.68, 14.89, 16.31, 17.20, 18.80, 19.23, 20.48, 20.93, 21.62, 22.39, 23.80, 24.84, 25.80, 26.92, 28.57 and 29.13± 0.5° .
In another embodiment, crystalline form 5 of Abemaciclib (1) obtained may be characterized by the XRD pattern as shown in figure 5 and having 2(6) theta values of 4.04, 7.26, 8.26, 10.05, 12.11, 13.88, 15.05, 15.94, 17.17, 18.83, 20.26, 21.33, 22.49, 24.10, 25.08, 25.96, 27.23, 4.55 and 11.66 ± 0.5°.

In another embodiment, crystalline form 6 of Abemaciclib (1) obtained may be characterized by the XRD pattern as shown in figure 6 and having 2(9) theta values of 4.37, 15.74, 26.60 and 17.08± 0.5°
In another embodiment, crystalline form 7 of Abemaciclib (1) obtained may be characterized by the XRD pattern as shown in figure 7 and having 2(0) theta values of 4.56, 10.38, 11.05, 11.77, 13.26, 13.82, 14.37, 14.92, 15.79, 16.64, 17.18, 18.46, 19.52, 20.93, 22.23, 23.05, 23.76, 25.57, 29.14 and 29.75± 0.5°.
In another embodiment, crystalline form 8 of Abemaciclib (1) obtained may be characterized by the XRD pattern as shown in figure 8 and having 2(9) theta values of
4.33, 5.88, 6.54, 8.92, 10.24, 11.13, 11.81, 13.27, 14.57, 15.30, 18.30, 19.17, 20.66,
22.55, 24.89, 25.90, 26.48, 27.65, 29.76, 31.35, 33.47 and 16.70± 0.5°.
In another embodiment, crystalline form 9 of Abemaciclib (1) obtained may be characterized by the XRD pattern as shown in figure 9 and having 2(9) theta values of
4.34, 5.86, 6.67, 9.07, 11.38, 12.76, 13.70, 15.37, 18.58, 20.94, 23.17, 25.89, 28.17,
29.12, 29.98, 12.04 and 21.7U 0.5°.
In another embodiment, crystalline form 10 of Abemaciclib (1) obtained may be characterized by the XRD pattern as shown in figure 10 and having 2(9) theta values of 4.56, 6.81, 10.96, 12.34, 13.71, 14.91, 16.18, 17.11, 18.76, 19.65, 20.73, 21.76, 22.25, 23.75, 24.40, 25.80, 27.52 and 28.64 ± 0.5°.
In another embodiment, crystalline form 11 of Abemaciclib (1) may be characterized by the XRD diffraction pattern as shown in figure 11 and having 2(0) theta values of 4.52, 10.92, 13.82, 14.90, 17.19, 20.92, 22.27, 23.14, 23.73 and 25.84 ± 0.5°.
In another embodiment, crystalline form 12 of Abemaciclib (1) may be characterized by the XRD pattern as shown in figure 12 and having 2(9) theta values of 4.56, 5.00,

7.20, 10.02, 10.78, 13.01, 13.81, 14.93, 16.19, 16.96, 18.68,20.63,22.19,24.65, 26.74 and 28.54 ±0.5°.
In another embodiment the amorphous forms of Abemaciclib (1) obtained may be characterized by the X-ray powder diffraction pattern as shown in figure 13.
Yet, in another embodiment, the present invention provides solid forms of Abemaciclib (1) comprising of crystalline form 1, form 2, form 3, form 4, form 5, form 6, form 7, form 8, form 9 , form 10, form 11 , form 12 and amorphous forms of Abemaciclib (1) prepared herein is having purity more than 99.0% by HPLC.
The following examples further illustrate the present invention, but should not be construed in anyway, as to limit its scope.
EXAMPLES
Example 1: Process for the preparation of crystalline form lof Abemaciclib (1)
lg of Abemaciclib (1) was added to 150 mL N-butyl acetate and heated to 65-70 °C. The reaction mass was then cooled to 0-5 °C. The solid formed was filtered under vacuum and dried in air tray dryer (ATD) to obtain crystalline form 1 of Abemaciclib (1). Yield: 90%.XRD: Figure: 1
Example 2: Process for the preparation of crystalline form 2 of Abemaciclib (1) lg of Abemaciclib (1) was added to 10 mL dichloromethane and heated to 35-40 °C. The reaction mass was cooled to 0-5 °C. The solid formed was filtered under vacuum and dried in air tray dryer (ATD) to obtain crystalline form 2 of Abemaciclib (1). Yield: 90%.XRD: Figure:2
Example 3: Process for the preparation of crystalline form 3 of Abemaciclib (1) lg of Abemaciclib (1) was added to 50 mL mixture of tetrahydrofuran and water and heated to 65-70 °C. The reaction mass was cooled to 0-5 °C. The solid formed was filtered under vacuum and dried to obtain crystalline form 3 of Abemaciclib (1). Yield: 90%.XRD: Figure:3

Example 4: Process for the preparation of crystalline form 4 of Abemaciclib (1)
lg of Abemaciclib (1) was added to 50 mL mixture of tetrahydrofuran and water and
heated to 65-70 °C. The reaction mass was cooled to 0-5 °C. The solid formed was
filtered under vacuum and poured in petri dish. The material was further dried in air
tray dryer (ATD) to obtain crystalline form 4 of Abemaciclib (1). Yield: 90%.XRD:
Figure:4
Example 5: Process for the preparation of crystalline form 5 of Abemaciclib (1)
lg of Abemaciclib (1) was added to 50 mL mixture of acetonitrile and methyl tertiary
butyl ether (8:2) and heated to 50-55 °C. The reaction mass was cooled to 0-5 °C. The
solid formed was filtered under vacuum and dried in air tray dryer (ATD) to obtain
crystalline form 5 of Abemaciclib (1). Yield: 90 %.XRD: Figure:5
Example 6: Process for the preparation of crystalline form 6 of Abemaciclib (1)
lg of Abemaciclib (1) was added to 50 mL mixture of dichloromethane and water (8:2)
and heated to 40-45 °C. The reaction mass was cooled to 0-5 °C. The solid formed was
filtered under vacuum and dried in air tray dryer (ATD) to obtain crystalline form 6 of
Abemaciclib (1). Yield: 90%.XRD: Figure:6
Example 7: Process for the preparation of crystalline form 7 of Abemaciclib (1)
lg of Abemaciclib (1) was added to 50 mL mixture of acetone and water (8:2) and
heated to 50-55 °C. The reaction mass was cooled to 0-5 °C. The solid formed was
filtered under vacuum and dried in air tray dryer (ATD) to obtain crystalline form 7 of
Abemaciclib (1). Yield: 80%.XRD: Figure:7
Example 8: Process for the preparation of crystalline form 8 of Abemaciclib (1)
lg of Abemaciclib (1) was added to 50 mL mixture of acetonitrile and water (8:2) and
heated to 70-75 °C. The reaction mass was cooled to 0-5°C.The solid formed was
filtered under vacuum and dried in air tray dryer (ATD) to obtain crystalline form 8 of
Abemaciclib (1). Yield: 80%.XRD: Figure:8
Example 9: Process for the preparation of crystalline form 9 of Abemaciclib (1)
lg of Abemaciclib (1) was added to 45 mL mixture of acetone and water (8:2) and
heated to 50-55 °C. The reaction mass was cooled to 0-5°C.The solid formed was

filtered under vacuum and dried in air tray dryer (ATD) to obtain crystalline form 9 of
Abemaciclib (1). Yield: 80%.XRD: Figure: 9
Example 10: Process for the preparation of crystalline form 10 of Abemaciclib (1)
1 gm of crystalline form 4 of Abemaciclib (1) was transferred to a petri dish and kept
at 25-30 °C for 7 days to yield crystalline form 10 of Abemaciclib (1). Yield: 86 %.
XRD: Figure: 10
Example 11: Alternative process for the preparation of crystalline form 10 of
Abemaciclib (1)
1 gm of crystalline form 4 of Abemaciclib (1) was transferred to a petri dish and dried
in vacuum tray dryer (VTD) at 70 to 75 °C for 24hrs to yield crystalline form 10 of
Abemaciclib (1). Yield: 80%.
Example 12: Alternative process for the preparation of crystalline form 10 of
Abemaciclib (1)
1 gm of crystalline form 4 of Abemaciclib (1) was transferred to a Buchi flask and
dried in vacuum at 70 to 75°C for 24hrs to yield crystalline form 10 of Abemaciclib
(1). Yield: 86%.
Example 13: Process for the preparation of crystalline form 11 of Abemaciclib (1)
1 gm of crystalline form 4 of Abemaciclib (1) and grinded in a Mortar and pestle to
yield crystalline form 11 of Abemaciclib (1). Yield: 80 %. XRD: Figure: 11
Example 14: Process for the preparation of crystalline form 12 of Abemaciclib (1)
1 gm of crystalline form 4 of Abemaciclib (1) was transferred to potassium bromide
(KBr) sample holder and 5 tons of pressure was applied for 2-3 mins in hydraulic
pressure instrument to yield crystalline form 12 of Abemaciclib (1). Yield: 86 %. XRD:
Figure: 12
Example 15: Process for the preparation of amorphous form of Abemaciclib (1)
lg of Abemaciclib (1) was added to a mixture of acetone and water (8:2) and heated to
35-40 °C. The solution so obtained was added to heptane and cooled to 0-5 °C. The
solid formed was filtered under vacuum and dried in air tray dryer (ATD) to obtain
amorphous form of Abemaciclib (1). Yield: 80%.XRD: Figure: 13

Example 16: Alternative process for the preparation of amorphous form of Abemaciclib (1)
lg of Abemaciclib (1) was added to a mixture of ethyl acetate and methanol (8:2) and heated to 55-60 °C. The solution so obtained was added to a mixture of heptane and methyl tertiary butyl ether and cooled to 0-5 °C. The solid formed was filtered under vacuum and dried to obtain amorphous form of Abemaciclib (1). Yield: 80%. Example 17: Alternative process for the preparation of amorphous form of Abemaciclib (1)
1 gm of crystalline form 4 of Abemaciclib (1) was transferred to potassium bromide (KBr) sample holder and 10 tons of pressure was applied for 2-3 mins in hydraulic pressure instrument to yield amorphous form of Abemaciclib (1). Yield: 86 %.

We Claim:
1. A process for the preparation of form 1 and form 2 of Abemaciclib (1),
comprising:
a) providing s solution of Abemaciclib (1) in a suitable solvent;
b) heating the reaction mass to a suitable temperature;
c) cooling the reaction mass to a suitable temperature; and
d) isolating the crystalline form of Abemaciclib (1).
2. A process for the preparation of crystalline form 3, form 5, form 6, form 7, form
8, form 9 of Abemaciclib (1), comprising:
a) providing a solution of Abemaciclib (1) in a mixture of suitable solvents;
b) heating the reaction mass to a suitable temperature;
c) cooling the reaction mass to a suitable temperature; and
d) isolating crystalline form of Abemaciclib (1) using a suitable technique.
3. A process for the preparation of form 4 of Abemaciclib (1), comprising:
a) providing s solution of Abemaciclib (1) in a mixture of suitable solvents;
b) heating the reaction mass to a suitable temperature;
c) cooling the reaction mass to a suitable temperature; and
d) isolating Abemaciclib (1) using a suitable technique to yield form 4 of Abemaciclib (1).
4. A process for the preparation of form 10, form 11 and form 12 of Abemaciclib
(1), comprising:
a) providing form 4 of Abemaciclib (1); and
b) isolating the crystalline form of Abemaciclib (1) using a suitable technique.

5. A process for the preparation of amorphous form of Abemaciclib (1),
comprising:
a) providing s solution of Abemaciclib (1) in a mixture of suitable solvents;
b) heating the reaction mass to a suitable temperature;
c) adding hot Abemaciclib (1) solution to a mixture of solvents at a suitable temperature; and
d) isolating amorphous form of Abemaciclib (1) using a suitable technique.

6. The process according to claim 1, claim 2, claim 3, claim 4 and claim 5 is wherein the solvents are selected from a group comprising of water, ethanol, methanol acetone, acetonitrile, nitromethane, 1,4-dioxane, diethyl ether, dichloromethane, ethyl acetate, N-butyl acetate ,N, N-dimethylformamide, methyl tertiary butyl ether, hexane, cyclohexane, toluene, tetrahydrofuran , heptane or mixtures thereof.
7. The process according to claim 1, claim 2, claim 3, claim 4 and claim 5 wherein the suitable drying and isolating techniques used for the isolation of the solid forms of Abemaciclib (1) may be selected from a group comprising of solvent evaporation, distillation, lyophilization or freeze drying, spray drying, agitated thin film drying (ATFD), air tray drying (ATD), cooling the solvent, adding anti-solvent to the reaction mixture and combination thereof.

8. The process according to claim 1, claim 2, claim 3, claim 4 and claim 5 wherein the reaction mixture was heated to a suitable temperature of 30-90 °C and cooled to a suitable temperature of-5 to 10 °C.
9. The process according to claim 1, claim 2, claim 3, claim 4 and claim 5, where the solid forms of Abemaciclib (1) comprises of crystalline form 1, form 2, form 3, form 4, form 5, form 6, form 7, form 8, form 9 , form 10, form 11 , form 12 and amorphous forms prepared herein is having purity more than 99.0% by HPLC.

10. The process according to claim 8 , wherein the solid forms of Abemaciclib (1) are having X-ray powder diffraction pattern as shown in figure 1, figure 2, figure 3, figure 4, figure 5 , figure 6, figure 7, figure 8, figure 9, figure 10, figure 11, figure 12 and figure 13.