Scheme 8. Syntheses of analogs 58–63 ^a.

^aReagents and conditions: (a) 1,2,3-Benzotriazole, SOCl₂, CH₂Cl₂, 4 h, 91–100% (b) MgBr₂·OEt, iPr₂NEt, CH₂Cl₂, 12 h, 60–69% (c) 4-(bromomethyl)benzenesulfonamide, Cs₂CO₃, DMSO, 1 h, 55–83% (d) TMS-Cl, NCS, CH₂Cl₂, 0 °C-rt, 3 h, 73–94 % (e) 4-hydroxybenzenesulfonamide, K₂CO₃, DMSO, 50 °C, 1 h, 31–49% (f) TsOH, EtOH, reflux, 12 h, 77–83% (mixture) (g) LiOH, THF-MeOH, 1 h.