There are provided compounds of Formula (I) wherein three of A1, A2, A3, and A4 represent CH and one of A1, A2, A3, and A4 represents CR1； R1 represents SO2R2 or NHCOR2 wherein R2 represents C1-C6 alkyl optionally substituted by one or more halogen, hydroxyl or alkoxy groups； R9 represents C6-C10 aryl； or a pharmaceutically acceptable salt thereof.
