| abstract |
The invention concerns a diaryl ether heterocycle of the formula I, or a pharmaceutically-acceptable salt thereof, <CHEM> wherein Ar<1> is optionally substituted phenyl or naphthyl; X<1> is oxy, thio, sulphinyl or sulphonyl; Ar<2> is optionally substituted phenylene, or a 6-membered heterocyclene moiety containing up to three nitrogen atoms; R<1> is (1-6C)alkyl, (3-6C)alkenyl, (3-6C)alkynyl, cyano-(1-4C)alkyl or (2-4C)alkanoyl, or optionally substituted benzoyl; and R<2> and R<3> together form a group of the formula -A<2>-X<2>-A<3>- wherein each of A<2> and A<3> is (1-4C)alkylene and X<2> is oxy, thio, sulphinyl, sulphonyl or imino. The invention also concerns processes for the manufacture of a diaryl ether heterocycle of the formula I, or a pharmaceutically-acceptable salt thereof, and pharmaceutical compositions containing said heterocycle. The compounds of the invention are inhibitors of the enzyme 5-lipoxygenase. |