Scheme 2: Synthesis of 8-substituted imidazobenzodiazepine bivalent ligands. Reagents and Conditions. (a) DMSO, 180°C, 90%; (b) bromine, sodium acetate, and acetic acid, r.t., 80%; (c) LDA, THF, and diethyl chlorophosphate, 0°C; (d) LDA, THF, and ethyl isocyanoacetate; (e) trimethylsilyl acetylene, Pd(OAc)2(PPh3)2, triethylamine, acetonitrile, and reflux, 80%; (f) tetrabutylammonium fluoride, THF, and H2O, r.t., 88%; (g) 2N NaOH and ethanol, 70°C, 90%; (h) CDI, DMF, HO(CH2)3OH, and DBU, 60%; (i) Pd/C, H2, ethanol, and DCM, 90%.