2-pyrimidinyl-pyrazolopyridines ErbB kinase inhibitor

A compound of formula (I): ** ** Formula wherein: a is 0, 1, 2 or 3; each R1 is the same or different and is independently selected from halogen, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, Ay, Het, -OR6, -R4OR6, -OC (O) R6, -C (O) R6, -R4C (O) R6, -C (O) NR6R7, -R4C (O) NR6R7, -CO2R6, -C (S) R6, -C (S) NR6R7, -S (O) FR6, -R4S (O) FR6, -S (O) 2NR6R7, -NR6R7, -R4NR6R7, -N (R6) -R4R7, -N (R 6) -R 4 -OR 7, -N (R6) -R4-S (O) FR7, -N (R6) -R4-CN, -C (NH) NR6R7, -N (R6) C (O) R6, -N (R6) S (O) 2R6, -N (R6) -C (O) -NR6R7, -N ( R6) -S (O) 2NR6R7, -CN and -NO2; f is 0, 1 or 2; Ay is aryl optionally substituted 1, 2 or 3 times with a substituent selected from halogen, C1-3 alcoxiC1-3, NH2, N (H) C1-3alkyl, N (C1-3alkyl) 2, CN and alkyl NO2; Het is a heterocycle or 5-6 membered heteroaryl having 1 or 2 heteroatoms selected from N, O and S, yopcionalmente substituted 1, 2 or 3 times with a substituent selected from halogen, C1-3, C1-3alkoxy, hydroxyl, oxo, C (O) (C1-3 alkyl), SO3 (H), SO2 (C1-3 alkyl), C1-3 SO3 (H), C1-3alkyl-SO2 (C1-3 alkyl) , NH2, N (H) C1-3alkyl, N (C1-3alkyl) 2, CN and NO2; ring A is selected from aryl, heterocycle and heteroaryl; R9 is C1-4 alkylene, C2-4 alkenylene or C3-4 cycloalkylene; Y1 is -C (O) -, -N (H) C (O) -, -C (S) - or -N (H) C (S) -.