To a stirred solution of Mono-Propargyl Curcumin 5 (63 mg, 0.16 mmol) and 2-(2-(2-azidoethoxy)ethoxy)ethanol (46 mg, 0.26 mmol) in tBuOH (1.1 mL) and CHCl3 (0.3 mL) was added a prepared solution of Cu(OAc)2 (8 mg, 0.03 mmol) and sodium ascorbate (13 mg, 0.07 mmol) in H2O (1.3 mL). After vigorous stirring overnight the solvent was removed under vacuum. The mixture was dissolved in CHCl3, washed with H2O and the organic phase was separated, dried over Na2SO4 and evaporated. Purification was performed by column chromatography, eluting with CH2Cl2-CH2Cl2: MeOH 98:2. Yield 26%. NMR NMR 1H (CDCl3), δ (ppm): 3.55-3.60 (m, 8H); 3.72-3.72 (t, 3H); 3.87-3.94 (m, 8H); 4.54-4.55 (t, 2H); 5.80 (s, 1H); 6.07 (s, 1H); 6.46-6.50 (dd, 2H); 6.92-6.94 (d, 1H); 7.05-7.12 (m, 5H); 7.56-7.60 (q, 2H); 7.92 (s, 1H).). MS (ESI) calcd. for C30H35N3O9: 581.61. Found: 582.3 [M+H]+, 604.3 [M++Na], 620.3 [M++K].
