Scheme 2. Synthesis of compounds 7–11. Reagents and conditions: (viii) morpholine derivative, DIPEA, DCM, 0 °C → rt, o/n; (ix) 1) n-BuLi, CuI, −78 °C → r.t., o/n; 2) HCl conc., MeOH, 45 °C, 4–6 h; 3) NaOH, H2O, r.t., 1–16 h; (x) 1) boronic ester (for 7, 9–11) or boronic ester generated in situ (for 8), XPhosPdG2 (cat.), K3PO4, dioxane/H2O, 95 °C, 2–16 h; 2) HCl, dioxane/H2O, 60 °C, 3–16 h (for 7–9, 11). See ESI† for details.
