Scheme 1

Synthesis of Compounds 8a-l. Reagents and conditions: (a) Bromoacetonitrile, K₂CO₃, DMF (b): Pimelic acid anhydride, 1,4-dioxane (c): MeOH, Cat. SOCl₂, reflux (d): Pyridine, (C₂H₅)₃N, (NH₄)₂S₅ (e): R₁-Ph-CO-CH₂-Cl, EtOH, reflux (f): NH₂OH·HCl, KOH, MeOH.