Abstract: The invention concerns compounds of the formula (I): wherein ring A is phenyl or a 5- or 6-membered heterocyclic ring as defined herein; Z is —O—, —NH— or —S—; m is an integer from 0 to 5 inclusive; R1 is hydrogen, hydroxy, halogeno, nitro, trifluoromethyl, cyano, C1-3alkyl, C1-3alkoxy, C1-3alkylthio, or —NR5R6 (wherein R5 and R6, which may be the same or different, are hydrogen or C1-3alkyl); R2 is hydrogen, hydroxy, halogeno, C1-3alkyl, C1-3alkoxy, trifluoromethyl, amino or nitro; R3 is hydroxy, halogeno, C1-3alkyl, C1-3alkoxy, C1-3alkanoyloxy, trifluoromethyl, cyano, amino or nitro; provided that when ring A is a 5- or 6-membered heterocyclic ring, at least one R3 is either hydroxy or halogeno; X1 is —O—, —CH2—, —S—, —SO—, —SO2—, —NR7—, —NR7CO—, —CONR7—, —SO2NR7— or —NR7SO2—, (wherein R7 is hydrogen, C1-3alkyl or C1-3alkoxyC2-3alkyl); and R4 is selected from a number of groups defined herein comprising an C2-5alkylene, C3-5alkenylene or C3-5alkynylene chain wherein each methylene group (other than tha

Abstract: The invention concerns a compound of the formula (I); wherein Ring A is heterocyclyl; m is 0-4 and each R1 is a group such as hydroxy, halo, trifluoromethyl and cyano; Ring B is ring such as thienyl, thiadiazolyl, thiazolyl, pyrimidyl, pyrazinyl, pyridazinyl and pyridyl; R2 is halo and n is 0-2; and each R4 is a group such as hydroxy, halo, trifluoromethyl and cyano; p is 0-4; and R3 is amino or hydroxy; or pharmaceutically-acceptable salts or in-vivo-hydrolysable ester or amide thereof; processes for their preparation, pharmaceutical compositions containing them and their use in the treatment of diseases or medical conditions mediated by histone deacetylase.