Br[C:2]1[CH:7]=[CH:6][C:5]([O:8][CH3:9])=[CH:4][C:3]=1[O:10][CH3:11].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[CH2:31]([OH:35])[CH2:32][C:33]#[CH:34]>C(NCC)C.[Pd](Cl)Cl.[Cu]I>[CH3:11][O:10][C:3]1[CH:4]=[C:5]([O:8][CH3:9])[CH:6]=[CH:7][C:2]=1[C:34]#[C:33][CH2:32][CH2:31][OH:35]1-Bromo-2,4-dimethoxybenzene (10 g 0.046 mol), palladium chloride (0.2 g 0.11 mmol) and triphenylphosphine (0.6 g 0.0023 mol) were dissolved in diethylamine (100 mL) under a nitrogen atmosphere. Copper (I) iodide (0.44 g 0.0023 mol) and 3-butyn-1-ol (7 mL 0.092 mol) were added into the reaction mixture at once. The mixture was stirred overnight at 55° C. under a nitrogen atmosphere. The catalyst was filtered off from the reaction mixture and the same amount of palladium chloride, triphenylphosphine, copper (I) iodide and 3-butyn-1-ol were added. The reaction mixture was stirred and heated at 85° C. for 48 hours. Then the solvent was removed at reduced pressure and water (approx. 100 mL) was added to the residue. The mixture was extracted with ethyl acetate (350 mL) passed through a pad of silica gel and concentrated. The product was purified by flash chromatography (silica gel, 1:1 hexanes/ethyl acetate). Compound 75 (4.2 g, 24%) was isolated as a brown oil. 1H NMR (300 MHz, CDCl3) δ2.24 (t, 1H), 2.73 (t, 2H), 3.80 (br s, 5H), 3.87 (s, 3H), 6.43 (m, 2H), 7.30 (m, 1H).
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