Pyrazolyl-pyrimidine derivatives as kinase inhibitors

A compound of formula (I):

• wherein
• R1 is hydrogen, halogen or an optionally substituted group selected from amino, straight or branched (C1-C6) alkyl, (C3-C7) cycloalkyl, cycloalkyl-alkyl, aryl, arylalkyl, heterocyclyl and heterocyclylalkyl;
• R2 is hydrogen or an optionally substituted group selected from straight or branched (C1-C6) alkyl, straight or branched (C2-C6) alkenyl, (C3-C7) cycloalkyl, cycloalkylalkyl, aryl, arylalkyl, heterocyclyl and heterocyclylalkyl;
• R3 is a group selected from CN, —CONR″R′″, —CON(OR′″)R″ and COOR″, wherein R″ and R′″ are, each independently, hydrogen or an optionally substituted group selected from straight or branched (C1-C6) alkyl, (C3-C7) cycloalkyl, cycloalkyl-alkyl, aryl, arylalkyl, heterocyclyl and heterocyclylalkyl or, together with the nitrogen atom to which they are bound, R″ and R′″ may form a 5-to 7-membered heteroaryl or heterocyclyl group, optionally containing one additional heteroatom selected from N, O and S;
• X is a single bond or a divalent radical selected from —NR′—, —O—, —S—, —SO—, —SO2— and —OSO2—, wherein R′ is hydrogen or an optionally substituted straight or branched (C1-C6) alkyl, (C3-C7) cycloalkyl, cycloalkyl-alkyl, aryl, arylalkyl, heterocyclyl and heterocyclylalkyl or, together with the nitrogen atom to which they are bound, R′ and R1 may form a 5- to 7-membered heteroaryl or heterocyclyl group optionally containing one additional heteroatom selected from N, O and S;
• R4 is a group selected from hydrogen, halogen and cyano;
• or a pharmaceutically acceptable salt thereof, with the proviso that the following compounds are excluded:
• N-tert-butyl-1-(6-methoxypyridin-3-yl)-5-(pyrimidin-4-yl)-1H-pyrazole-3-carboxamide,
• methyl 1-(6-methoxypyridin-3-yl)-5-[2-(methylsulfanyl)pyrimidin-4-yl]-1H-pyrazole-3-carboxylate,
• methyl 1-(6-methoxypyridin-3-yl)-5-(pyrimidin-4-yl)-1H-pyrazole-3-carboxylate,
• 1-(6-methoxypyridin-3-yl)-5-(pyrimidin-4-yl)-1H-pyrazole-3-carboxylic acid and
• [1(6-methoxypyridin-3-yl)-5-(pyrimidin-4-yl)-IH-pyrazol-3-yl](4-methylpiperazin-1-yl)methanone and with the proviso that when R3 is —CONR″R′″, neither R″ nor R′″ are arylalkyl.