N-(Isoxazol-5-yl)-sulfonamide derivatives and their use as endothelin antagonists

摘要

Isoxazoles of formula (I) below have good affinity for endothelin receptors, and are selective for ETA over ETB. <CHEM> wherein R<1> is either a)a phenyl group; or b)an optionally benzo-fused 5- or 6-membered heterocyclic group with one to three heteroatoms in the heterocyclic ring, which heteroatoms are independently selected from N, O and S; or CHR<6>CHR<7>Ph, CR<6>:CR<7>Ph; each of which groups (a) (b) and (c) is optionally substituted by up to three substituents each independently selected from: i)halo; ii)C1-6 alkyl optionally substituted by OH, halogen, NR<4>R<5> OCOR<4> or CO2R<4>; iii)CN; iv)O(C1-8 alkyl optionally substituted by one or more halogen); and v)CO2R<4>; R<2> is aryl<1> or het<1>, R<3> is H, C1-6 alkyl, C(O)R<4>, CONHaryl<1>, CONHhet<1>, aryl<1> and het<1> Such compounds are useful in the treatment of conditions mediated by endothelin.