A compound represented by the chemical formula (A) or a pharmaceutically acceptable salt thereof, in which: L is selected from the group consisting of: (f) -S (O) n-, in which n is 0, 1 or 2； Ar1 is an optionally mono, di or trisubstituted aromatic or heteroaromatic six atom ring, in which the heteroaromatic ring may contain 1, 2 or 3 heteroatoms selected from N, S and O, in which the substituents are independently selected from the group consisting of: (a) halo, (b) - C1-4alkyl, (c) -O- C1-4alkyl, (d) -CF3, (e) -NH2, (f) -NH-CH3, (g) -CN, (h) -C (O) NH2, and (i) -S (O) n-CH3； Ar2 is a 5.6 cyclic heterocyclic ring optionally mono, di or trisubstituted condensed selected from the group consisting of: or an N-oxide thereof, in which the substituents are independently selected from the group consisting of (a) halo , (b) - C1-4alkyl, (c) -O- C1-4alkyl, (d) -CF3, (e) -NH2, and (f) -NH2-CH3, (g) -NH2-CH2CF3, (h ) -C (O) -morpholinyl, (i) -C (O) -NR1R2, (j) -C (O) OH, (k) -CN, (1) a heteroaromatic or heterocyclic 5 or 6 membered ring which it contains 1, 2 or 3 heteroatoms selected from the group consisting of S, O and N； R1, R2, R3 and R4 are independently selected from the group consisting of (a) hydrogen, and (b) C1-4alkyl, or R1 and R2 or R3 and R4 can be joined together to form a saturated ring of 5 or 6 members, said ring optionally containing a heteroatom selected from S, N and O.Un compuesto representado por la fórmula química (A) o una sal farmacéuticamente aceptable del mismo, en la que: L se selecciona entre el grupo que consiste en: (f) -S(O)n- , en la que n es 0, 1 ó 2； Ar1 es un anillo de seis átomos aromático o heteroaromático opcionalmente mono, di o trisustituido, en el que el anillo heteroaromático puede contener 1, 2 ó 3 heteroátomos seleccionados entre N, S y O, en el que los sustituyentes se seleccionan independientemente entre el grupo que consiste en: (a) halo, (b) - alquiloC1-4, (c) -O- alquiloC1-4, (d) -CF3, (e) -NH2, (f) -NH-CH3, (g) -CN, (h) -C(O
