Scheme 5. Syntheses of Naphthyridine, Quinazoline, and 2-Pyridylquinoline Analogues of 15a.

Reagents and conditions: (i) PhCOCl, TEA, DCM, DMAP, rt; (ii) BuLi, THF, −78 °C then N-methoxy-N-methylacetamide, −30 °C; (iii) for 17c, PhCO₂H, PyBroP, DIPA, DMAP, DCM, rt; (iv) NaOH, dioxane, 110 °C; (v) for 18e, NaOH, DMSO, 110 °C; (vi) for 19a–e, Cs₂CO₃, acetone, rt; (vii) PyBroP, DIPA, DCM, rt; (viii) NaOH, dioxane, 110 °C; (ix) for 22a, K₂CO₃, MeCN, 50 °C; (x) Cs₂CO₃, acetone, rt.