Clicked Cinnamic/Caffeic Esters and Amides as Radical Scavengers and 5-Lipoxygenase Inhibitors

Scheme 2

Synthesis of caffeoyl triazole derivatives 15a–h and 16a–h. Reagents, conditions, yield: i = SOCl₂, DMF_cat, reflux 3 h then N₃EtOH, pyridine/CH₂Cl₂, rt overnight, 65%, or (COCl₂), DMF_cat, CH₂Cl₂, 0°C 3 h then N₃EtNH₂, pyridine/CH₂Cl₂, rt overnight, 71%. ii = HCCH, CuI, NEt₃, DMSO, rt overnight, 81%, or R₁CCH, CuSO₄-5H₂O, sodium ascorbate, H₂O/THF, rt overnight, 43–93%. iii = guanidinium HCl, NEt₃, MeOH/CH₂Cl₂, rt 4h, 28–81%.