7,8-Dihydroxyflavone → 7,8-Bis-(1,1-dimethyl-prop-2-ynyloxy)-2-phenyl-chromen-4-one

Participants

Reaction Conditions

Reaction Steps

To a suspension of 7,8-dihydroxy-2-phenyl-chromen-4-one (510 mg, 2 mmol) and CuCl2 (16 mg, 0.12 mmol) in acetonitrile (3 mL) was added 3-chloro-3-methyl-1-butyne (0.5 mL, 4.56 mmol) and 1,8-diazabicyclo[5.4.0]undec-7-ene (0.78 mL, 5.2 mmol) slowly at 0° C. The dark mixture was stirred at 0° C. for 5 h and then at room temperature overnight. The solvent was evaporated and the residue was purified by column chromatography (SiO2, EtOAc:hexanes/10-50%) to give the title compound as a white solid (540 mg, 69%): 1H NMR (CDCl3, 300 MHz) δ 8.02 (m, 2H), 7.96 (d, J=9.0 Hz, 1H), 7.69 (d, J=9.0 Hz, 1H), 7.53 (m, 3H), 6.78 (s, 1H), 2.66 (s, 1H), 2.26 (s, 1H), 1.81 (s, 6H), 1.76 (s, 6H).

Provenance & Evidence