An aryl ether derivative of the formula ##STR1## in which A is an oxygen atom or an >N--R.sub.1 grouping,R.sub.1 is a hydrogen atom or a lower alkyl radical,B is an alkylene radical containing 2 to 4 carbon atoms,R.sub.2 and R.sub.3 each independently is a hydrogen or halogen atom, hydroxyl group or lower alkyl, lower alkoxy or lower alkanoyl radical,R.sub.4 is a hydrogen atom or an acyl radical, andn is an integer from 1 to 5,or a pharmacologically acceptable salt thereof, which possesses anti-allergic activity.