Ether derivatives having 5-lipoxygenase inhibitory activity

An ether derivative of the formula I

• Q.sup.1 --X--Ar--Q.sup.2 I
• wherein
• Q.sup.1 is a 9-, 10- or 11-membered bicyclic heterocyclic moiety having one or two nitrogen heteroatoms and optionally having one further heteroatom selected from nitrogen, oxygen and sulphur, and Q.sup.1 may optionally bear up to four substituents selected from halogeno, hydroxy, cyano, formyl, oxo, thioxo, (1-4C)alkyl, (3-4C)alkenyl, (3-4C)alkynyl, (1-4C)alkoxy, fluoro-(1-4C)alkyl, hydroxy-(1-4C)alkyl, (2-5C)alkanoyl, phenyl, benzoyl and benzyl, and wherein said phenyl, benzoyl and benzyl substituents may optionally bear one or two substituents selected from halogeno, (1-4C)alkyl and (1-4C)alkoxy;
• X is oxy, thio, sulphinyl or sulphonyl;
• Ar is phenylene, pyridinediyl, pyrimidinediyl, thiophenediyl, furandiyl, thiazolediyl, oxazolediyl, thiadiazolediyl or oxadiazolediyl which may optionally bear one or two substituents selected from halogeno, cyano, trifluoromethyl, hydroxy, amino, (1-4C)alkyl, (1-4C)alkoxy, (1-4C)alkylamino and di-(1-4C)alkylamino;
• and
• Q.sup.2 is selected from the group consisting of the formulae II and III:
• ##STR5## wherein R.sup.1 is hydrogen, (2-5C)alkanoyl or benzoyl, and wherein said benzoyl group may optionally bear one or two substituents selected from halogeno, (1-4C)alkyl and (1-4C)alkoxy;
• R.sup.2 is (1-4C)alkyl;
• and
• R.sup.3 is hydrogen or (1-4C)alkyl;
• or R.sup.2 and R.sup.3 are linked to form a methylene, vinylene, ethylene or trimethylene group;
• or a pharmaceutically-acceptable salt thereof.