QUINOXALINYL DERIVATIVES SUITABLE FOR USE IN LEUKOTRIENE MEDIATED DISEASE

The invention concerns a heterocycle of the formula I wherein Q is an optionally substituted 6-membered monocyclic or 10-membered bicyclic heterocyclic moiety containing one or two nitrogen atoms; A is (1-6C)alkylene, (3-6C)alkenylene, (3-6C)alkynylene or cyclo(3-6C)alkylene; X is oxy, thio, sulphinyl, sulphonyl or imino; Ar is phenylene which may optionally bear one or two substituents or Ar is an optionally substituted 6-membered heterocyclene moiety containing up to three nitrogen atoms; R is hydrogen, (1-6C)alkyl, (3-6C)alkenyl, (3-6C)alkynyl, cyano-(1-4C)alkyl or (2-4C)alkanoyl, or optionally substituted benzoyl; and R and R together form a group of the formula -A -X -A - which, together with the carbon atom to which A and A are attached, defines a ring having 4 to 7 ring atoms, wherein A and A , which may be the same or different, each is (1-4C)alkylene and X is oxy, thio, sulphinyl, sulphonyl or imino; or a pharmaceutically-acceptable salt thereof. The compounds of the invention are inhibitors of the enzyme 5-lipoxygenase.