N‐((Arylmethoxy)phenyl) and N‐((Arylmethoxy)naphthyl) Sulfonamides: Potent Orally Active Leukotriene D4 Antagonists of Novel Structure.

Two series of compounds, N-[(arylmethoxy)phenyl] sulfonamides and N-[(arylmethoxy)naphthyl] sulfonamides, were prepared as leukotriene D4 (LTD4) antagonists. In the phenyl series, N-[3-(2-quinolinylmethoxy)phenyl]-trifluoromethanesulfonamide (Wy-48,252, 16) was the most potent inhibitor of LTD4-induced bronchoconstriction in the guinea pig. With an intragastric ID50 of 0.1 mg/kg (2-h pretreatment), 16 was 300 times more potent than LY-171,883. Compound 16 also intragastrically inhibited ovalbumin-induced bronchoconstriction in the guinea pig with an ID50 of 0.6 mg/kg. In vitro against LTD4-induced contraction of isolated guinea pig trachea pretreated with indomethacin and L-cysteine, 16 produced a pKB value of 7.7. In the rat PMN assay 16 inhibited both 5-lipoxygenase and cyclooxygenase (IC50's = 4.6 and 3.3 microM). In the naphthyl series, N-[7-(2-quinolinylmethoxy)-2-naphthyl]trifluoromethanesulfonamide (Wy-48,090, 47) in addition to potent LTD4 antagonist activity (on isolated guinea pig trachea 47 had a pKB value of 7.04) also had antiinflammatory activity (63% inhibition at 50 mg/kg in the rat carrageenan paw edema assay and 34% inhibition of TPA-induced inflammation at 1 mg/ear in the mouse ear edema model). Perhaps the antiinflammatory activity of 47 was due to its additional activity of inhibiting both 5-lipoxygenase and cyclooxygenase enzymes (IC50's = 0.23 and 11.9 microM, respectively, in rat PMN).