COMPOUNDS OF FORMULA (I) IN SALT OR SOLVATE FORM, WHEREIN W, RX, RY, R¹, R², R³, R⁴, R⁵, R⁶ AND R⁷ AND A HAVE THE MEANINGS AS INDICATED IN THE SPECIFICATION, ARE USEFUL FOR TREATING DISEASES MEDIATED BY THE β₂-ADRENORECEPTOR. PHARMACEUTICAL COMPOSITIONS THAT CONTAIN THE COMPOUNDS AND PROCESSES FOR PREPARING THE COMPOUNDS ARE ALSO DESCRIBED.