Potassium Carbonate → 3'-Methoxyisoflavone

Participants

Reaction Conditions

Reaction Steps

Prepared using a modified procedure of Hoshino et al. (Bulletin of the Chemical Society of Japan 1988, 61, (8), 3008-3010; herein incorporated by reference in its entirety). To a 10 mL round bottom flask was added 3-bromochromone (Gammill, R. B. Synthesis-Stuttgart 1979, (11), 901-903; herein incorporated by reference in its entirety) (225 mg, 1 mmol), K2CO3 (415 mg, 3 mmol), 3-methoxyphenylboronic acid (167 mg, 1.1 mmol), and PdCl2(PPh3)2 (21 mg, 0.03 mmol). The flask was equipped with a reflux condenser and purged with N2, followed by addition of THF/H2O (2.5 mL/0.5 mL). The reaction was stirred at 80° C. for 4 hr. The reaction was then run through a plug of Celite and rinsed with EtOAc. The organic phase was washed with brine and dried over anhydrous Na2SO4. Purified by flash column chromatography (SiO2, 15% EtOAc/Hex) and recrystallized from CH2Cl2/Hex to afford 5 (128 mg, 51%) as an off-white solid. Analytical data for isoflavone 5: 1H NMR (500 MHz, CDCl3) δ 8.34 (d, J=9.5 Hz, 1H), 8.06 (s, 1H), 7.70 (app t, J=8.5 Hz, 1H), 7.50 (d, J=8.5 Hz, 1H), 7.45 (app t, J=7.5 Hz, 1H), 7.37 (app t, J=8 Hz, 1H), 7.19 (s, 1H), 7.15 (d, J=7 Hz, 1H), 6.96 (d, J=8.5 Hz, 1H), 3.87 (s, 3H); 13C NMR (125 MHz, CDCl3) δ 176.4, 159.8, 156.4, 153.4, 133.9, 133.4, 129.8, 126.7, 125.5, 124.8, 121.5, 118.3, 114.7, 114.4, 55.6; LCMS: Mass calculated for C16H12O3, [M+H]+, 253. Found 253.

Provenance & Evidence