Scheme 2.

Synthesis of compounds 24–77. Reagents and conditions: (a) 1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate, N,N-diisopropylethylamine, DMF, 4-aminomethyl-1-Boc-piperidine or another amine,12 h; (b) aryl boronic acid or aryl 4,4,5,5-tetramethyl-1,3,2-dioxaborolane, tetrakis(triphenylphosphine)palladium, Na₂CO₃, 1,4-dioxane-H₂O, 100 °C; (c) a amine or phenol, tris(dibenzylideneacetone)dipalladium, 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl, t-BuOH, toluene, 100 °C; (d) HCl (4 N in 1,4-dioxane), CH₂Cl₂, 0 °C.