Figure 7.

Synthesis of compounds A-10.

Notes: Reagents and conditions: (a) DMF, K₂CO₃, 80°C, 4 hours; (b) Fe, 70% EtOH, AcOH, reflux, 6 hours; (c) Dimethylformamide dimethyl acetal, 70°C–75°C; (d) Compound 4, AcOH, 70°C–75°C; (e) NiCl₂(dppf), 1,3-bis-(diphenylphosphino)propane, pinacol borane, diisopropylethylamine, dioxane, MW, 160°C, 15 minutes; (f) NH₂CH₂CHBr, Pd(PPh₃)₄, Cs₂CO₃, DME, MW, 140°C, 15 minutes; (g) EDC·HCl, HOBt, Et₃N, 3-hydroxy-3-methylbutanoic acid, DMF, 3 days.

Abbreviations: DMF, dimethylformamide; EtOH, ethanol; AcOH, acetic acid; MW, molecular weight; HOBt, 1-hydroxybenzotriazole monohydrate.