Amino-phthalazinone derivatives active as kinase inhibitors, process for their preparation and pharmaceutical compositions containing them

Abstract

Compounds which are amino-phthalazinone derivatives and pharmaceutically acceptable salts thereof, together with pharmaceutical compositions comprising them are disclosed; these compounds or compositions are useful in the treatment of diseases caused by and/or associated with an altered protein kinase activity such as cancer, cell proliferative disorders, Alzheimer's disease, viral infections, auto-immune diseases and neurodegenerative disorders.

1 . A method for treating diseases caused by and/or associated with an altered protein kinase activity which comprises administering to a mammal in need thereof an effective amount of an amino-phthalazinone derivative represented by formula (I)  
       
         
           
           
               
               
           
         
       
       wherein 
 Ra and Rb are, each independently, a hydrogen atom or a group, optionally further substituted, selected from straight or branched C 1 -C 6  alkyl, C 3 -C 6  cycloalkyl or cycloalkyl C 1 -C 6  alkyl, aryl, aryl C 1 -C 6  alkyl, 5 to 7 membered heterocyclyl or heterocyclyl C 1 -C 6  alkyl with from 1 to 3 heteroatoms selected among nitrogen, oxygen or sulfur; or one of Ra or Rb is hydrogen or an optionally substituted straight or branched C 1 -C 6  alkyl group, and the other is a group selected from —COR′, —CONHR′, —COOR′ or —SO 2 R′, wherein R′ is hydrogen or an optionally substituted group selected from alkyl, cycloalkyl, cycloalkylalkyl, aryl, arylalkyl, heterocyclyl or heterocyclylalkyl, as set forth above;  
 R 1  is a group of formula —CHR 4 R 5  wherein R 4  and R 5  are, each independently, hydrogen or an optionally substituted group selected from straight or branched C 1 -C 6  alkyl, C 3 -C 6  cycloalkyl or cycloalkyl C 1 -C 6  alkyl, aryl, aryl C 1 -C 6  alkyl, 5 to 7 membered heterocyclyl or heterocyclyl C 1 -C 6  alkyl with from 1 to 3 heteroatoms selected among nitrogen, oxygen or sulfur; or R 1  is a group of formula —NHR′, —NR′COR″, —NR′CONHR″ or —NR′SO 2 R″, wherein R′ has the above reported meanings other than hydrogen, and R″ is hydrogen or has the meanings set forth above for R′;  
 R 2  is a hydrogen atom or it is a group, optionally further substituted, selected from straight or branched C 1 -C 6  alkyl, C 3 -C 6  cycloalkyl or cycloalkyl C 1 -C 6  alkyl, aryl, aryl C 1 -C 6  alkyl, 5 to 7 membered heterocyclyl or heterocyclyl C 1 -C 6  alkyl with from 1 to 3 heteroatoms selected among nitrogen, oxygen or sulfur;  
 any R 3 , being placed in one or more of the free positions 5, 6 and 8 of the phthalazinone ring are, independently from each other, halogen, nitro, carboxy, cyano or a group optionally further substituted selected from straight or branched C 1 -C 6  alkyl, C 3 -C 6  cycloalkyl or cycloalkyl C 1 -C 6  alkyl, aryl, aryl C 1 -C 6  alkyl, 5 to 7 membered heterocyclyl or heterocyclyl C 1 -C 6  alkyl with from 1 to 3 heteroatoms selected among nitrogen, oxygen or sulfur; or R 3  is a group selected from —COR′, —CONHR′, —SO 2 R′, —NR′R″, —NR′COR″, —NR′CONHR′ or —NR′S 2 R″, wherein R′ and R″ are, the same or different, hydrogen or a group as set forth above;  
 m is 0 or an integer from 1 to 3;  
 or a pharmaceutically acceptable salt thereof.  
 
     
     
         2 . The method of  claim 1  wherein the disease caused by and/or associated with an altered protein kinase activity is a cell proliferative disorder selected from the group consisting of cancer, Alzheimer's disease, viral infections, auto-immune diseases and neurodegenerative disorders.  
     
     
         3 . The method of  claim 2  wherein the cancer is selected from carcinoma, squamous cell carcinoma, hematopoietic tumors of lymphoid or myeloid lineage, tumors of mesenchymal origin, tumors of the central and peripheral nervous system, melanoma, seminoma, teratocarcinoma, osteosarcoma, xeroderma pigmentosum, keratocanthoma, thyroid follicular cancer and Kaposi's sarcoma.  
     
     
         4 . The method of  claim 1  wherein the cell proliferative disorder is selected from benign prostate hyperplasia, familial adenomatosis, polyposis, neuro-fibromatosis, psoriasis, vascular smooth cell proliferation associated with atherosclerosis, pulmonary fibrosis, arthritis glomerulonephritis and post-surgical stenosis and restenosis.  
     
     
         5 . The method of  claim 1  which provides tumor angiogenesis and metastasis inhibition.  
     
     
         6 . The method of  claim 1  further comprising subjecting the mammal in need thereof to a radiation therapy or chemotherapy regimen in combination with at least one cytostatic or cytotoxic agent.  
     
     
         7 . The method of  claim 1  wherein the mammal in need thereof is a human.  
     
     
         8 . The method of  claim 1  wherein, within the compounds of formula (I), one of Ra and Rb is a hydrogen atom and the other is a group —COR′, —CONHR′, —COOR′ or —SO 2 R′, wherein R′ is as defined in  claim 1 .  
     
     
         9 . The method of  claim 1  wherein, within the compounds of formula (I), one of Ra and Rb is a hydrogen atom and the other is a group —COR′, —CONHR′, —COOR′ or —SO 2 R′, R 2  is hydrogen, m is 0 and R 1  and R′ are as defined in  claim 1 .  
     
     
         10 . A method for inhibiting protein kinase activity which comprises contacting the said kinase with an effective amount of a compound as defined in  claim 1 .  
     
     
         11 . An amino-phthalazinone derivative represented by formula (I)  
       
         
           
           
               
               
           
         
       
       wherein 
 Ra and Rb are, each independently, a hydrogen atom or a group, optionally further substituted, selected from straight or branched C 1 -C 6  alkyl, C 3 -C 6  cycloalkyl or cycloalkyl C 1 -C 6  alkyl, aryl, aryl C 1 -C 6  alkyl, 5 to 7 membered heterocyclyl or heterocyclyl C 1 -C 6  alkyl with from 1 to 3 heteroatoms selected among nitrogen, oxygen or sulfur; or one of Ra or Rb is hydrogen or an optionally substituted straight or branched C 1 -C 6  alkyl group, and the other is a group selected from —COR′, —CONHR′, —COOR′ or —SO 2 R′, wherein R′ is hydrogen or an optionally substituted group selected from alkyl, cycloalkyl, cycloalkylalkyl, aryl, arylalkyl, heterocyclyl or heterocyclylalkyl, as set forth above;  
 R 1  is a group of formula —CHR 4 R 5  wherein R 4  and R 5  are, each independently, hydrogen or an optionally substituted group selected from straight or branched C 1 -C 6  alkyl, C 3 -C 6  cycloalkyl or cycloalkyl C 1 -C 6  alkyl, aryl, aryl C 1 -C 6  alkyl, 5 to 7 membered heterocyclyl or heterocyclyl C 1 -C 6  alkyl with from 1 to 3 heteroatoms selected among nitrogen, oxygen or sulfur; or R 1  is a group of formula —NHR′, —NR′COR″, —NR′CONHR″ or —NR′SO 2 R″, wherein R′ has the above reported meanings other than hydrogen, and R″ is hydrogen or has the meanings set forth above for R′;  
 R 2  is a hydrogen atom or it is a group, optionally further substituted, selected from straight or branched C 1 -C 6  alkyl, C 3 -C 6  cycloalkyl or cycloalkyl C 1 -C 6  alkyl, aryl, aryl C 1 -C 6  alkyl, 5 to 7 membered heterocyclyl or heterocyclyl C 1 -C 6  alkyl with from 1 to 3 heteroatoms selected among nitrogen, oxygen or sulfur;  
 any R 3 , being placed in one or more of the free positions 5, 6 and 8 of the phthalazinone ring are, independently from each other, halogen, nitro, carboxy, cyano or a group optionally further substituted selected from straight or branched C 1 -C 6  alkyl, C 3 -C 6  cycloalkyl or cycloalkyl C 1 -C 6  alkyl, aryl, aryl C 1 -C 6  alkyl, 5 to 7 membered heterocyclyl or heterocyclyl C 1 -C 6  alkyl with from 1 to 3 heteroatoms selected among nitrogen, oxygen or sulfur; or R 3  is a group selected from —COR′, —CONHR′, —SO 2 R′, —NR′R″, —NR′COR″, —NR′CONHR′ or —NR′SO 2 R″, wherein R′ and R″ are, the same or different, hydrogen or a group as set forth above;  
 m is 0 or an integer from 1 to 3;  
 or a pharmaceutically acceptable salt thereof;  
 the compounds N- [3,4-dihydro-4-oxo-1- (4-pyridinylmethyl) -6-phthalazinyl]-acetamide and N-[3,4-dihydro-4-oxo-1-(4-pyridinylmethyl)-6-phthalazinyl]-2,2,2-trifluoro-acetamide, being excluded.  
 
     
     
         12 . A compound of formula (I) according to  claim 11  wherein one of Ra or Rb is a hydrogen atom or an optionally substituted straight or branched C 1 -C 6  alkyl group and the other is a group —COR′ wherein R′ is an optionally substituted group selected from alkyl, cycloalkyl, cycloalkylalkyl, aryl, arylalkyl, heterocyclyl or heterocyclylalkyl, as defined in  claim 11 , and R 1 , R 2 , R 3  and m are as defined in  claim 11 .  
     
     
         13 . A compound of formula (I) according to  claim 12  wherein R 1  is a group —CHR 4 R 5  wherein R 4  and R 5  are as defined in  claim 11 , R 2  is hydrogen and m is 0.  
     
     
         14 . A compound of formula (I) according to  claim 11  wherein one of Ra or Rb is a hydrogen atom or an optionally substituted straight or branched C 1 -C 6  alkyl group and the other is a group —CONHR′ wherein R′ is a hydrogen atom or an optionally substituted group selected from alkyl, cycloalkyl, cycloalkylalkyl, aryl, arylalkyl, heterocyclyl or heterocyclylalkyl, as defined in  claim 11 , and R 1 , R 2 , R 3  and m are as defined in  claim 11 .  
     
     
         15 . A compound of formula (I) according to  claim 14  wherein R 1  is a group —CHR 4 R 5  wherein R 4  and R 5  are as defined in  claim 11 , R 2  is hydrogen and m is 0.  
     
     
         16 . A compound of formula (I) according to  claim 11  wherein one of Ra or Rb is a hydrogen atom or an optionally substituted straight or branched C 1 -C 6  alkyl group and the other is a group —COOR′ wherein R′ is a hydrogen atom or an optionally substituted group selected from alkyl, cycloalkyl, cycloalkylalkyl, aryl, arylalkyl, heterocyclyl or heterocyclylalkyl, as defined in  claim 11 , and R 1 , R 2 , R 3  and m are as defined in  claim 11 .  
     
     
         17 . A compound of formula (I) according to  claim 16  wherein R 1  is a group —CHR 4 R 5  wherein R 4  and R 5  are as defined in  claim 11 , R 2  is hydrogen and m is 0.  
     
     
         18 . A compound of formula (I) according to  claim 11  wherein one of Ra or Rb is a hydrogen atom or an optionally substituted straight or branched C 1 -C 6  alkyl group and the other is a group —SO 2 R′ wherein R′ is an optionally substituted group selected from alkyl, cycloalkyl, cycloalkylalkyl, aryl, arylalkyl, heterocyclyl or heterocyclylalkyl, as defined in  claim 11 , and R 1 , R 2 , R 3  and m are as defined in  claim 11 .  
     
     
         19 . A compound of formula (I) according to  claim 18  wherein R 1  is a group —CHR 4 R 5  wherein R 4  and R 5  are as defined in  claim 11 , R 2  is hydrogen and m is 0.  
     
     
         20 . A compound of formula (I) according to  claim 11  wherein Ra and Rb are both hydrogen atoms and R 1 , R 2 , R 3  and m are as defined in  claim 11 .  
     
     
         21 . A compound of formula (I) according to  claim 20  wherein R 1  is a group —CHR 4 R 5  wherein R 4  and R 5  are as defined in  claim 11 , R 2  is hydrogen and m is 0.  
     
     
         22 . A compound of formula (I) according to  claim 11  wherein one of Ra or Rb is a hydrogen atom or an optionally substituted straight or branched C 1 -C 6  alkyl and the other is a group, optionally further substituted, selected from alkyl, cycloalkylalkyl, arylalkyl or heterocyclylalkyl as defined in  claim 11 , and R 1 , R 2 , R 3  and m are as defined in  claim 11 .  
     
     
         23 . A compound of formula (I) according to  claim 22  wherein R 1  is a group —CHR 4 R 5  wherein R 4  and R 5  are as above defined, R 2  is hydrogen and m is 0.  
     
     
         24 . A compound of formula (I) as defined in  claim 11 , optionally in the form of a pharmaceutically acceptable salt, selected from: 
 1. 4-(4-Oxo-6-propionylamino-3,4-dihydro-phthalazin-1-ylmethyl)-benzoic acid methyl ester;    2. 4-[4-Oxo-6-(4-trifluoromethyl-benzoylamino)-3,4-dihydro-phthalazin-1-ylmethyl]-benzoic acid methyl ester;    3. 4-{6-[(Furan-2-carbonyl)-amino]-4-oxo-3,4-dihydro-phthalazin-1-ylmethyl}-benzoic acid methyl ester;    4. 4-[6-(3,4-Dimethoxy-benzoylamino)-4-oxo-3,4-dihydro-phthalazin-1-ylmethyl]-benzoic acid methyl ester;    5. 4-[6-(3-Cyclopentyl-propionylamino)-4-oxo-3,4-dihydro-phthalazin-1-ylmethyl]-benzoic acid methyl ester;    6. 4-[4-Oxo-6-(2-propyl-pentanoylamino)-3,4-dihydro-phthalazin-1-ylmethyl]-benzoic acid methyl ester;    7. 4-{4-Oxo-6-[3-(3-trifluoromethyl-phenyl)-ureido]-3,4-dihydro-phthalazin-1-ylmethyl}-benzoic acid methyl ester;    8. 4-{6-[3-(3-Methoxy-phenyl)-ureido]-4-oxo-3,4-dihydro-phthalazin-1-ylmethyl}-benzoic acid methyl ester;    9. 4-[4-Oxo-6-(3-p-tolyl-ureido)-3,4-dihydro-phthalazin-1-ylmethyl]-benzoic acid methyl ester;    10. 4-{6-[3-(2,4-Difluoro-phenyl)-ureido]-4-oxo-3,4-dihydro-phthalazin-1-ylmethyl}-benzoic acid methyl ester;    11. 4-{6-[3-(3,4-Dichloro-phenyl)-ureido]-4-oxo-3,4-dihydro-phthalazin-1-ylmethyl}-benzoic acid methyl ester;    12. 4-[4-Oxo-6-(3-pyridin-3-yl-ureido)-3,4-dihydro-phthalazin-1-ylmethyl]-benzoic acid methyl ester;    13. 4-(6-Amino-4-oxo-3,4-dihydro-phthalazin-1-ylmethyl)-benzoic acid methyl ester;    14. N-[1-(4-Chloro-3-fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-propionamide;    15. N-[1-(4-Chloro-3-fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-4-trifluoromethyl-benzamide;    16. Furan-2-carboxylic acid [1-(4-chloro-3-fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-amide;    17. N-[1-(4-Chloro-3-fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3,4-dimethoxy-benzamide;    18. N-[1-(4-Chloro-3-fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-cyclopentyl-propionamide;    19. 2-Propyl-pentanoic acid [1-(4-chloro-3-fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-amide;    20. 1-[1-(4-Chloro-3-fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3-trifluoromethyl-phenyl)-urea;    21. 1-[1-(4-Chloro-3-fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3-methoxy-phenyl)-urea;    22. 1-[1-(4-Chloro-3-fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-p-tolyl-urea;    23. 1-[1-(4-Chloro-3-fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(2,4-difluoro-phenyl)-urea;    24. 1-[1-(4-Chloro-3-fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3,4-dichloro-phenyl)-urea;    25. 1-[1-(4-Chloro-3-fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-pyridin-3-yl-urea;    26. 7-Amino-4-(4-chloro-3-fluoro-benzyl)-2H-phthalazin-1-one;    27. N-{1-[(E)-3-(4-Nitro-phenyl)-allyl]-4-oxo-3,4-dihydro-phthalazin-6-yl}-propionamide;    28. N-{1-[(E)-3-(4-Nitro-phenyl)-allyl]-4-oxo-3,4-dihydro-phthalazin-6-yl}-4-trifluoromethyl-benzamide;    29. Furan-2-carboxylic acid {1-[(E)-3-(4-nitro-phenyl)-allyl]-4-oxo-3,4-dihydro-phthalazin-6-yl}-amide;    30. N-{1-[(E)-3-(4-Nitro-phenyl)-allyl]-4-oxo-3,4-dihydro-phthalazin-6-yl}-3,4-dimethoxy-benzamide;    31. N-{1-[(E)-3-(4-Nitro-phenyl)-allyl]-4-oxo-3,4-dihydro-phthalazin-6-yl}-3-cyclopentyl-propionamide;    32. 2-Propyl-pentanoic acid {1-[(E)-3-(4-nitro-phenyl)-allyl]-4-oxo-3,4-dihydro-phthalazin-6-yl}-amide;    33. 1-{1-[(E)-3-(4-Nitro-phenyl)-allyl]-4-oxo-3,4-dihydro-phthalazin-6-yl}-3-(3-trifluoromethyl-phenyl)-urea;    34. 1-{1-[(E)-3-(4-Nitro-phenyl)-allyl]-4-oxo-3,4-dihydro-phthalazin-6-yl}-(3-methoxy-phenyl)-urea;    35. 1-{1-[(E)-3-(4-Nitro-phenyl)-allyl]-4-oxo-3,4-dihydro-phthalazin-6-yl}-3-p-tolyl-urea;    36. 1-{1-[(E)-3-(4-Nitro-phenyl)-allyl]-4-oxo-3,4-dihydro-phthalazin-6-yl}-3-(2,4-difluoro-phenyl)-urea;    37. 1-{1-[(E)-3-(4-Nitro-phenyl)-allyl]-4-oxo-3,4-dihydro-phthalazin-6-yl}-3-(3,4-dichloro-phenyl)-urea;    38. 1-{1-[(E)-3-(4-Nitro-phenyl)-allyl]-4-oxo-3,4-dihydro-phthalazin-6-yl}-3-pyridin-3-yl-urea;    39. 7-Amino-4-[(E)-3-(4-nitro-phenyl)-allyl]-2H-phthalazin-1-one;    40. N-(4-Oxo-1-thiophen-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-propionamide;    41. N-(4-Oxo-1-thiophen-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-4-trifluoromethyl-benzamide;    42. Furan-2-carboxylic acid (4-oxo-1-thiophen-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-amide;    43. N-(4-Oxo-1-thiophen-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3,4-dimethoxy-benzamide;    44. N-(4-Oxo-1-thiophen-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3-cyclopentyl-propionamide;    45. 2-Propyl-pentanoic acid (4-oxo-1-thiophen-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-amide;    46. 1-(4-Oxo-1-thiophen-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3-(3-trifluoromethyl-phenyl)-urea;    47. 1-(4-Oxo-1-thiophen-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-(3-methoxy-phenyl)-urea;    48. 1-(4-Oxo-1-thiophen-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3-p-tolyl-urea;    49. 1-(4-Oxo-1-thiophen-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3-(2,4-difluoro-phenyl)-urea;    50. 1-(4-Oxo-1-thiophen-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3-(3,4-dichloro-phenyl)-urea;    51. 1-(4-Oxo-1-thiophen-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3-pyridin-3-yl-urea;    52. 7-Amino-4-thiophen-3-ylmethyl-2H-phthalazin-1-one;    53. N-[1-(3-Methoxy-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-propionamide;    54. N-[1-(3-Methoxy-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-4-trifluoromethyl-benzamide;    55. Furan-2-carboxylic acid [1-(3-methoxy-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-amide;    56. N-[1-(3-Methoxy-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3,4-dimethoxy-benzamide;    57. N-[1-(3-Methoxy-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-cyclopentyl-propionamide;    58. 2-Propyl-pentanoic acid [1-(3-methoxy-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-amide;    59. 1-[1-(3-Methoxy-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3-trifluoromethyl-phenyl)-urea;    60. 1-[1-(3-Methoxy-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-(3-methoxy-phenyl)-urea;    61. 1-[1-(3-Methoxy-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-p-tolyl-urea;    62. 1-[1-(3-Methoxy-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(2,4-difluoro-phenyl)-urea;    63. 1-[1-(3-Methoxy-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3,4-dichloro-phenyl)-urea;    64. 1-[1-(3-Methoxy-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-pyridin-3-yl-urea;    65. 7-Amino-4-(3-methoxy-benzyl)-2H-phthalazin-1-one;    66. N-(4-Oxo-1-propyl-3,4-dihydro-phthalazin-6-yl)-propionamide;    67. N-(4-Oxo-1-propyl-3,4-dihydro-phthalazin-6-yl)-4-trifluoromethyl-benzamide;    68. Furan-2-carboxylic acid (4-oxo-1-propyl-3,4-dihydro-phthalazin-6-yl)-amide;    69. N-(4-Oxo-1-propyl-3,4-dihydro-phthalazin-6-yl)-3,4-dimethoxy-benzamide;    70. N-(4-Oxo-1-propyl-3,4-dihydro-phthalazin-6-yl)-3-cyclopentyl-propionamide;    71. 2-Propyl-pentanoic acid (4-oxo-1-propyl-3,4-dihydro-phthalazin-6-yl)-amide;    72. 1-(4-Oxo-1-propyl-3,4-dihydro-phthalazin-6-yl)-3-(3-trifluoromethyl-phenyl)-urea;    73. 1-(4-Oxo-1-propyl-3,4-dihydro-phthalazin-6-yl)-(3-methoxy-phenyl)-urea;    74. 1-(4-Oxo-1-propyl-3,4-dihydro-phthalazin-6-yl)-3-p-tolyl-urea;    75. 1-(4-Oxo-1-propyl-3,4-dihydro-phthalazin-6-yl)-3-(2,4-difluoro-phenyl)-urea;    76. 1-(4-Oxo-1-propyl-3,4-dihydro-phthalazin-6-yl)-3-(3,4-dichloro-phenyl)-urea;    77. 1-(4-Oxo-1-propyl-3,4-dihydro-phthalazin-6-yl)-3-pyridin-3-yl-urea;    78. 7-Amino-4-propyl-2H-phthalazin-1-one;    79. N-[1-(3,3-Dimethyl-butyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-propionamide;    80. N-[1-(3,3-Dimethyl-butyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-4-trifluoromethyl-benzamide;    81. Furan-2-carboxylic acid [1-(3,3-dimethyl-butyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-amide;    82. N-[1-(3,3-Dimethyl-butyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3,4-dimethoxy-benzamide;    83. N-[1-(3,3-Dimethyl-butyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-cyclopentyl-propionamide;    84. 2-Propyl-pentanoic acid [1-(3,3-dimethyl-butyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-amide;    85. 1-[1-(3,3-Dimethyl-butyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3-trifluoromethyl-phenyl)-urea;    86. 1-[1-(3,3-Dimethyl-butyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-(3-methoxy-phenyl)-urea;    87. 1-[1-(3,3-Dimethyl-butyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-p-tolyl-urea;    88. 1-[1-(3,3-Dimethyl-butyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(2,4-difluoro-phenyl)-urea;    89. 1-[1-(3,3-Dimethyl-butyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3,4-dichloro-phenyl)-urea;    90. 1-[1-(3,3-Dimethyl-butyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-pyridin-3-yl-urea;    91. 7-Amino-4-(3,3-dimethyl-butyl)-2H-phthalazin-1-one;    92. N-[4-Oxo-1-(3-phenyl-propyl)-3,4-dihydro-phthalazin-6-yl]-propionamide;    93. N-[4-Oxo-1-(3-phenyl-propyl)-3,4-dihydro-phthalazin-6-yl]-4-trifluoromethyl-benzamide;    94. Furan-2-carboxylic acid [4-oxo-1-(3-phenyl-propyl)-3,4-dihydro-phthalazin-6-yl]-amide;    95. N-[4-Oxo-1-(3-phenyl-propyl)-3,4-dihydro-phthalazin-6-yl]-3,4-dimethoxy-benzamide;    96. N-[4-Oxo-1-(3-phenyl-propyl)-3,4-dihydro-phthalazin-6-yl]-3-cyclopentyl-propionamide;    97. 2-Propyl-pentanoic acid [4-oxo-1-(3-phenyl-propyl)-3,4-dihydro-phthalazin-6-yl]-amide;    98. 1-[4-Oxo-1-(3-phenyl-propyl)-3,4-dihydro-phthalazin-6-yl]-3-(3-trifluoromethyl-phenyl)-urea;    99. 1-[4-Oxo-1-(3-phenyl-propyl)-3,4-dihydro-phthalazin-6-yl]-( 3-methoxy-phenyl)-urea;    100. 1-[4-Oxo-1-(3-phenyl-propyl)-3,4-dihydro-phthalazin-6-yl]-3-p-tolyl-urea;    101. 1-[4-Oxo-1-(3-phenyl-propyl)-3,4-dihydro-phthalazin-6-yl]-3-(2,4-difluoro-phenyl)-urea;    102. 1-[4-Oxo-1-(3-phenyl-propyl)-3,4-dihydro-phthalazin-6-yl]-3-(3,4-dichloro-phenyl)-urea;    103. 1-[4-Oxo-1-(3-phenyl-propyl)-3,4-dihydro-phthalazin-6-yl]-3-pyridin-3-yl-urea;    104. 7-Amino-4-(3-phenyl-propyl)-2H-phthalazin-1-one;    105. N-(4-Oxo-1-pyridin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-propionamide;    106. N-(4-Oxo-1-pyridin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-4-trifluoromethyl-benzamide;    107. Furan-2-carboxylic acid (4-oxo-1-pyridin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-amide;    108. N-(4-Oxo-1-pyridin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-succinamic acid ethyl ester;    109. N-(4-Oxo-1-pyridin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3-cyclopentyl-propionamide;    110. 2-Propyl-pentanoic acid (4-oxo-1-pyridin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-amide;    111. 1-(4-Oxo-1-pyridin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3-(3-trifluoromethyl-phenyl)-urea;    112. 1-(3-Methoxy-phenyl)-3-(4-oxo-1-pyridin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-urea;    113. 1-(4-Oxo-1-pyridin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3-p-tolyl-urea;    114. 1-(2,4-Difluoro-phenyl)-3-(4-oxo-1-pyridin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-urea;    115. 1-(3,4-Dichloro-phenyl)-3-(4-oxo-1-pyridin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-urea;    116. 1-(4-Oxo-1-pyridin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3-pyridin-3-yl-urea;    117. 7-Amino-4-pyridin-3-ylmethyl-2H-phthalazin-1-one    118. N-(4-Oxo-1-pyridin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-benzamide;    119. N-[1-(4-Chloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-propionamide;    120. N-[1-(4-Chloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-4-trifluoromethyl-benzamide;    121. Furan-2-carboxylic acid [1-(4-chloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-amide;    122. N-[1-(4-Chloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-succinamic acid ethyl ester;    123. N-[1-(4-Chloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-cyclopentyl-propionamide;    124. 2-Propyl-pentanoic acid [1-(4-chloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-amide;    125. 1-[1-(4-Chloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3-trifluoromethyl-phenyl)-urea;    126. 1-[1-(4-Chloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3-methoxy-phenyl)-urea;    127. 1-[1-(4-Chloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-p-tolyl-urea;    128. 1-[1-(4-Chloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(2,4-difluoro-phenyl)-urea;    129. 1-[1-(4-Chloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3,4-dichloro-phenyl)-urea;    130. 1-[1-(4-Chloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-pyridin-3-yl-urea;    131. 7-Amino-4-(4-Chloro-benzyl)-2H-phthalazin-1-one;    132. N-[1-(4-Cyano-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-propionamide;    133. N-[1-(4-Cyano-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-4-trifluoromethyl-benzamide;    134. Furan-2-carboxylic acid [1-(4-cyano-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-amide;    135. N-[1-(4-Cyano-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-succinamic acid ethyl ester;    136. N-[1-(4-Cyano-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-cyclopentyl-propionamide;    137. 2-Propyl-pentanoic acid [1-(4-cyano-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-amide;    138. 1-[1-(4-Cyano-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3-trifluoromethyl-phenyl)-urea;    139. 1-[1-(4-Cyano-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3-methoxy-phenyl)-urea;    140. 1-[1-(4-Cyano-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-p-tolyl-urea;    141. 1-[1-(4-Cyano-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(2,4-difluoro-phenyl)-urea;    142. 1-[1-(4-Cyano-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3,4-dichloro-phenyl)-urea;    143. 1-[1-(4-Cyano-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-pyridin-3-yl-urea;    144. 7-Amino-4-(4-Cyano-benzyl)-2H-phthalazin-1-one;    145. N-[1-(3-Fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-propionamide;    146. N-[1-(3-Fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-4-trifluoromethyl-benzamide;    147. Furan-2-carboxylic acid [1-(3-fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-amide;    148. N-[1-(3-Fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-succinamic acid ethyl ester;    149. N-[1-(3-Fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-cyclopentyl-propionamide;    150. 2-Propyl-pentanoic acid [1-(3-fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-amide;    151. 1-[1-(3-Fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3-trifluoromethyl-phenyl)-urea;    152. 1-[1-(3-Fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3-methoxy-phenyl)-urea;    153. 1-[1-(3-Fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-p-tolyl-urea;    154. 1-[1-(3-Fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(2,4-difluoro-phenyl)-urea;    155. 1-[1-(3-Fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3,4-dichloro-phenyl)-urea;    156. 1-[1-(3-Fluoro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-pyridin-3-yl-urea;    157. 7-Amino-4-(3-Fluoro-benzyl)-2H-phthalazin-1-one;    158. N-[1-(3-Methyl-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-propionamide;    159. N-[1-(3-Methyl-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-4-trifluoromethyl-benzamide;    160. Furan-2-carboxylic acid [1-(3-methyl-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-amide;    161. N-[1-(3-Methyl-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-succinamic acid ethyl ester;    162. N-[1-(3-Methyl-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-cyclopentyl-propionamide;    163. 2-Propyl-pentanoic acid [1-(3-methyl-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-amide;    164. 1-[1-(3-Methyl-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3-trifluoromethyl-phenyl)-urea;    165. 1-[1-(3-Methyl-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3-methoxy-phenyl)-urea;    166. 1-[1-(3-Methyl-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-p-tolyl-urea;    167. 1-[1-(3-Methyl-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(2,4-difluoro-phenyl)-urea;    168. 1-[1-(3-Methyl-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3,4-dichloro-phenyl)-urea;    169. 1-[1-(3-Methyl-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-pyridin-3-yl-urea;    170. 7-Amino-4-(3-Methyl-benzyl)-2H-phthalazin-1-one;    171. N-[1-(2,4-Dichloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-propionamide;    172. N-[1-(2,4-Dichloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-4-trifluoromethyl-benzamide;    173. Furan-2-carboxylic acid [1-(2,4-dichloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-amide;    174. N-[1-(2,4-Dichloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-succinamic acid ethyl ester;    175. N-[1-(2,4-Dichloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-cyclopentyl-propionamide;    176. 2-Propyl-pentanoic acid [1-(2,4-dichloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-amide;    177. 1-[1-(2,4-Dichloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3-trifluoromethyl-phenyl)-urea;    178. 1-[1-(2,4-Dichloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3-methoxy-phenyl)-urea;    179. 1-[1-(2,4-Dichloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-p-tolyl-urea;    180. 1-[1-(2,4-Dichloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(2,4-difluoro-phenyl)-urea;    181. 1-[1-(2,4-Dichloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-(3,4-dichloro-phenyl)-urea;    182. 1-[1-(2,4-Dichloro-benzyl)-4-oxo-3,4-dihydro-phthalazin-6-yl]-3-pyridin-3-yl-urea;    183. 7-Amino-4-(2,4-dichloro-benzyl)-2H-phthalazin-1-one;    184. N-(4-Oxo-1-quinolin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-propionamide;    185. N-(4-Oxo-1-quinolin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-4-trifluoromethyl-benzamide;    186. Furan-2-carboxylic acid (4-oxo-1-quinolin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-amide;    187. N-(4-Oxo-1-quinolin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-succinamic acid ethyl ester;    188. N-(4-Oxo-1-quinolin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3-cyclopentyl-propionamide;    189. 2-Propyl-pentanoic acid (4-oxo-1-quinolin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-amide;    190. 1-(4-Oxo-1-quinolin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3-(3-trifluoromethyl-phenyl)-urea;    191. 1-(4-Oxo-1-quinolin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3-(3-methoxy-phenyl)-urea;    192. 1-(4-Oxo-1-quinolin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3-p-tolyl-urea;    193. 1-(4-Oxo-1-quinolin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3-(2,4-difluoro-phenyl)-urea;    194. 1-(4-Oxo-1-quinolin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3-(3,4-dichloro-phenyl)-urea;    195. 1-(4-Oxo-1-quinolin-3-ylmethyl-3,4-dihydro-phthalazin-6-yl)-3-pyridin-3-yl-urea;    196. 7-Amino-4-quinolin-3-ylmethyl-2H-phthalazin-1-one;    197. N-[4-Oxo-1-(2-trifluoromethyl-benzyl)-3,4-dihydro-phthalazin-6-yl]-propionamide;    198. N-[4-Oxo-1-(2-trifluoromethyl-benzyl)-3,4-dihydro-phthalazin-6-yl]-4-trifluoromethyl-benzamide;    199. Furan-2-carboxylic acid [4-oxo-1-(2-trifluoromethyl-benzyl)-3,4-dihydro-phthalazin-6-yl]-amide;    200. N-[4-Oxo-1-(2-trifluoromethyl-benzyl)-3,4-dihydro-phthalazin-6-yl]-succinamic acid ethyl ester;    201. N-[4-Oxo-1-(2-trifluoromethyl-benzyl)-3,4-dihydro-phthalazin-6-yl]-3-cyclopentyl-propionamide;    202. 2-Propyl-pentanoic acid [4-oxo-1-(2-trifluoromethyl-benzyl)-3,4-dihydro-phthalazin-6-yl]-amide;    203. 1-[4-Oxo-1-(2-trifluoromethyl-benzyl)-3,4-dihydro-phthalazin-6-yl]-3-(3-trifluoromethyl-phenyl)-urea;    204. 1-[4-Oxo-1-(2-trifluoromethyl-benzyl)-3,4-dihydro-phthalazin-6-yl]-3-(3-methoxy-phenyl)-urea;    205. 1-[4-Oxo-1-(2-trifluoromethyl-benzyl)-3,4-dihydro-phthalazin-6-yl]-3-p-tolyl-urea;    206. 1-[4-Oxo-1-(2-trifluoromethyl-benzyl)-3,4-dihydro-phthalazin-6-yl]-3-(2,4-difluoro-phenyl)-urea;    207. 1-[4-Oxo-1-(2-trifluoromethyl-benzyl)-3,4-dihydro-phthalazin-6-yl]-3-(3,4-dichloro-phenyl)-urea;    208. 1-[4-Oxo-1-(2-trifluoromethyl-benzyl)-3,4-dihydro-phthalazin-6-yl]-3-pyridin-3-yl-urea;    209. 7-Amino-4-(2-trifluoromethyl-benzyl)-2H-phthalazin-1-one.    
     
     
         25 . A process for preparing the compounds of formula (I) as defined in  claim 11 , and the pharmaceutically acceptable salts thereof, which process comprises: 
 a) reacting a compound of formula (II)                        wherein R 3  and m are as defined in  claim 11  and Hal represents a halogen atom, with a suitable phosphine derivative (PL 3 ), under optional reductive conditions, so as to obtain a compound of formula (III)                          wherein P is a phosphorous atom and L are the phosphine ligands;      b) reacting the compound of formula (III) with an aldehydic Resin-CHO, in the presence of a suitable reducing agent, so as to obtain a resin supported compound of formula (IV)                        wherein R 3 , m, P, L, Hal and the Resin are as above defined;      c) reacting the compound of formula (IV) with a carbonyl derivative of formula (V) or a nitroso derivative of formula (VI)   R 4 —CO—R 5   (V)R′—NO  (VI) wherein R 4 , R 5  and R′ are as defined in  claim 11;  so as to obtain the compound of formula (VII)                          wherein A is a group ═CR 4 R 5  or ═NR′, respectively; and optionally reacting the compound of formula (VII) according to any one of the alternative steps d.1) or d.2) below 
 d.1) with one of the derivatives of formula (VIII), (IX), (X) or (XI), under optional basic conditions, 
 R′COZ  (VIII),R′NCO  (IX),R′OCOZ  (X),R′SO 2 Z  (XI) 
   wherein Z is a halogen atom or a suitable leaving group and R′ is as defined in  claim 11 , so as to obtain the compound of formula (XII)                          wherein Rb is —COR′, —CONHR′, —COOR′ or —SO 2 R′, respectively; or 
 d.2) with a compound of formula (XIII) 
 Rb-Z  (XIII) 
   wherein Z is a halogen atom and Rb is alkyl, cycloalkyl, cycloalkylalkyl, aryl, arylalkyl, heterocyclyl or heterocyclylalkyl as defined in  claim 11 , so as to obtain the corresponding compound of the above formula (XII);      e) reacting the thus obtained compounds of formula (VII) or (XII) with a hydrazine derivative of formula (XIV)   R 2 —NH—NH 2   (XIV) wherein R 2  is as defined in  claim 11 , so as to obtain the compounds of formula (XV) or (XVI), respectively                          wherein Rb, R 2 , R 3 , m and the Resin are as above defined and R 1  is a group of formula —CHR 4 R 5  or —NHR′ wherein R 4 , R 5  and R′ are as above defined;      f) reacting the compounds of formula (XV) or (XVI) under acidic conditions so as to obtain the compound of formula (I) and, whenever desired, converting it into another compound of formula (I) and/or into a pharmaceutically acceptable salt thereof.    
     
     
         26 . The process of  claim 25  wherein, in step a), the phosphine derivative is triphenylphosphine PPh 3 .  
     
     
         27 . The process of  claim 25  wherein, in step b), the reducing agent is selected from pyridine-borane complex, sodium cyanoboron hydride, sodium triacetate boron hydride or dimethylsufide borane.  
     
     
         28 . The process of  claim 25  wherein, in step d.1), it is used a compound of formula (VIII), (X) or (XI), wherein Z is a chlorine atom.  
     
     
         29 . The process of  claim 25  wherein, in step f), acidic conditions are reached by using trifluoroacetic acid.  
     
     
         30 . Any specific compound of formula (I), as defined in  claim 11 , which is obtainable, for instance through a combinatorial chemistry technique according to the process as set forth in  claim 25 , by first reacting the compound of formula (IV)  
       
         
           
           
               
               
           
         
       
       with each one of the aldehyde derivatives of formula (V), as set forth in table I; by reacting any of the resultant compounds of formula (VII) with each one of the acyl chloride derivatives of formula (VIII), as set forth in table II; by reacting any of the resultant compounds of formula (XII) with hydrazine; and by working according to step f) of the process of  claim 25 .  
     
     
         31 . Any specific compound of formula (I), as defined in  claim 11 , which is obtainable, for instance through a combinatorial chemistry technique according to the process as set forth in  claim 25 , by first reacting the compound of formula (IV)  
       
         
           
           
               
               
           
         
       
       with each one of the aldehyde derivatives of formula (V), as set forth in table I; by reacting any of the resultant compounds of formula (VII) with each one of the isocyanate derivatives of formula (IX), as set forth in table III; by reacting any of the resultant compounds of formula (XII) with hydrazine; and by working according to step f) of the process of  claim 25 .  
     
     
         32 . A library of two or more amino-phthalazinone derivatives of formula (I)  
       
         
           
           
               
               
           
         
       
       wherein 
 Ra and Rb are, each independently, a hydrogen atom or a group, optionally further substituted, selected from straight or branched C 1 -C 6  alkyl, C 3 -C 6  cycloalkyl or cycloalkyl C 1 -C 6  alkyl, aryl, aryl C 1 -C 6  alkyl, 5 to 7 membered heterocyclyl or heterocyclyl C 1 -C 6  alkyl with from 1 to 3 heteroatoms selected among nitrogen, oxygen or sulfur; or one of Ra or Rb is hydrogen or an optionally substituted straight or branched C 1 -C 6  alkyl group, and the other is a group selected from —COR′, —CONHR′, —COOR′ or —SO 2 R′, wherein R′ is hydrogen or an optionally substituted group selected from alkyl, cycloalkyl, cycloalkylalkyl, aryl, arylalkyl, heterocyclyl or heterocyclylalkyl, as set forth above; R 1  is a group of formula —CHR 4 R 5  wherein R 4  and R 5  are, each independently, hydrogen or an optionally substituted group selected from straight or branched C 1 -C 6  alkyl, C 3 -C 6  cycloalkyl or cycloalkyl C 1 -C 6  alkyl, aryl, aryl C 1 -C 6  alkyl, 5 to 7 membered heterocyclyl or heterocyclyl C 1 -C 6  alkyl with from 1 to 3 heteroatoms selected among nitrogen, oxygen or sulfur; or R 1  is a group of formula —NHR′, —NR′COR″, —NR′CONHR″ or —NR′SO 2 R″, wherein R′ has the above reported meanings other than hydrogen, and R″ is hydrogen or has the meanings set forth above for R′;  
 R 2  is a hydrogen atom or it is a group, optionally further substituted, selected from straight or branched C 1 -C 6  alkyl, C 3 -C 6  cycloalkyl or cycloalkyl C 1 -C 6  alkyl, aryl, aryl C 1 -C 6  alkyl, 5 to 7 membered heterocyclyl or heterocyclyl C 1 -C 6  alkyl with from 1 to 3 heteroatoms selected among nitrogen, oxygen or sulfur;  
 any R 3 , being placed in one or more of the free positions 5, 6 and 8 of the phthalazinone ring are, independently from each other, halogen, nitro, carboxy, cyano or a group optionally further substituted selected from straight or branched C 1 -C 6  alkyl, C 3 -C 6  cycloalkyl or cycloalkyl C 1 -C 6  alkyl, aryl, aryl C 1 -C 6  alkyl, 5 to 7 membered heterocyclyl or heterocyclyl C 1 -C 6  alkyl with from 1 to 3 heteroatoms selected among nitrogen, oxygen or sulfur; or R 3  is a group selected from —COR′, —CONHR′, —SO 2 R′, —NR′R″, —NR′COR″, —NR′CONHR′ or —NR′SO 2 R″, wherein R′ and R″ are, the same or different, hydrogen or a group as set forth above;  
 m is 0 or an integer from 1 to 3;  
 or a pharmaceutically acceptable salt thereof.  
 
     
     
         33 . A pharmaceutical composition comprising an effective amount of a compound of formula (I) as defined in  claim 11  and, at least, one pharmaceutically acceptable excipient, carrier or diluent.  
     
     
         34 . A pharmaceutical composition according to  claim 33  further comprising one or more chemotherapeutic agents, as a combined preparation for simultaneous, separate or sequential use in anticancer therapy.  
     
     
         35 . A product or kit comprising a compound of  claim 11  or a pharmaceutical composition thereof as defined in  claim 33 , and one or more chemotherapeutic agents, as a combined preparation for simultaneous, separate or sequential use in anticancer therapy.  
     
     
         36 . A compound of formula (I) or a pharmaceutically acceptable salt thereof, as defined in  claim 11 , for use as a medicament.  
     
     
         37 . Use of a compound of formula (I) or a pharmaceutically acceptable salt thereof, as defined in  claim 11 , in the manufacture of a medicament for treating diseases caused by and/or associated with an altered protein kinase activity.  
     
     
         38 . Use according to  claim 37  for treating tumors.