A compound of formula (I): or a pharmaceutically acceptable salt thereof, wherein: Ring A is selected from the group consisting of: wherein a nitrogen atom of ring A is optionally oxidized X is -CH2-, -CHF-, -CF2, -NH- or -O- Y is -O-, -S- or -C (Rm) (Rn) - each Rh is independently hydrogen, halo, -CN, -OH, -O- (C1-4 aliphatic), -NH2, -NH- (C1-4 aliphatic), -N (C1-4 aliphatic) 2, -SH, -S- (C1-4 aliphatic), or a C1-4 aliphatic group optionally substituted Rj is hydrogen, -OR 5, -SR 6, -N (R4) 2 or an aliphatic, aryl or heteroaryl, optionally substituted Rk is hydrogen, halo, -OR 5, -SR 6, -N (R4) 2 or C 1-4 aliphatic group optionally substituted Rm is hydrogen, fluoro, -N (R4) 2 or C 1-4 aliphatic group optionally substituted and Rn is hydrogen, fluoro or C1-4 aliphatic group 20 optionally substituted, or Rn and Rm together form> = O or> = C (R5) 2 R1 is hydrogen, chloro, bromo, fluoro, iodo, -NR7R8, -R 9, -SH, -SCH 3, -S-R10, -OH, -OCH3 or -O-R11 R2 is hydrogen, chloro, bromo, fluoro, iodo, -N (R6) 2, -CN, -O- (C1-4 aliphatic), -OH, -SR 6, or a C1-4 aliphatic group optionally substituted R3a is selected from the group consisting of hydrogen, fluoro, -CN, -N 3, hydroxy, -OR21, -NH2, -NH (R21), -25 N (H) CO2R21, -N (H) C (O) R21 , -CON (H) R21, -C (O) R5, -OC (O) N (H) R21, -OC (O) R21, -OC (O) OR21, -C 1-4 fluoroaliphatic or -C1- 4 aliphatic optionally substituted with one or two substituents independently selected from the group consisting of -OR 5x, -N (R 4x) (R 4y), -CO2R5x, or -C (O) N (R 4x) (R 4y) R3b is selected from the group consisting of hydrogen, fluoro, C1-4 aliphatic, and C1-4 fluoroaliphatic.Un compuesto de fórmula (I): o una de sus sales farmacéuticamente aceptables, donde: El anillo A se selecciona del grupo que consiste en: donde un átomo de nitrógeno del anillo A está opcionalmente oxidado X es -CH2-, -CHF-, -CF2, -NH- u -O- Y es -O-, -S- o -C(Rm)(Rn)- cada Rh es independientemente hidrógeno, halo, -CN, -OH, -O-(C1-4 alifático), -NH2, -NH-(C1-4 alif
