Diethyl Ether → Dimethylcurcumin

Reaction equation

[CH3:1][O:2][C:3]1C(O)=C[CH:6]=[C:5](/[CH:10]=[CH:11]/[C:12]([CH2:14][C:15](/[CH:17]=[CH:18]/[C:19]2[CH:27]=[C:24]([O:25][CH3:26])[C:22]([OH:23])=[CH:21][CH:20]=2)=[O:16])=[O:13])[CH:4]=1.[N+](=[CH2:30])=[N-].C[CH2:32][O:33][CH2:34][CH3:35]>CO>[CH3:32][O:33][C:34]1[CH:35]=[CH:6][C:5](/[CH:10]=[CH:11]/[C:12](/[OH:13])=[CH:14]/[C:15](/[CH:17]=[CH:18]/[C:19]2[CH:20]=[CH:21][C:22]([O:23][CH3:30])=[C:24]([O:25][CH3:26])[CH:27]=2)=[O:16])=[CH:4][C:3]=1[O:2][CH3:1]

Participants

Procedure

Curcumin (1) in Et2O and MeOH was treated with excess of diazomethane in ether for 24 h. The solvents were removed in vacuo and the residue was purified by silica gel column chromatography and PLC to yield yellow needles of 4 (yield 19.8%); mp 129-130° C. (MeOH) (Roughley et al., J. Chem. Soc. Perkin I, 2379-2388 (1973))(128-130° C.); 1H NMR (300 MHz, CDCl3): δ 3.93 (12H, s, OCH3×4), 5.82 (1H, s, 1-H), 6.48 (2H, d, 16 Hz), 6.88 (2H, d, J=8 Hz), 7.08 (2H, bs), 7.15 (2H, bd), 7.61 (2H, J=16 Hz); 13CNMR (300 MHz, CDCl3): δ 55.9, 56.0, 101.3, 109.8, 111.1, 122.0, 122.6, 128.1, 140.4, 149.2, 151.0, 183.2.