反应详情

温度

200 °C

The crude 5-Methoxy-2-(4-methoxyphenyl)-4-methylbenzofuran 136 (0.134 g) was taken into a sealed tube along with enough pyridine hydrochloride to fill the tube halfway and heated at 200° C. for 2.5 hours. The reaction was dissolved into a mixture of ethyl acetate and 1 N HCl. The layers were separated and the aqueous layer was extracted with ethyl acetate (2×). The combined organics was washed with 1 N HCl (1×), water (1×) and then dried over magnesium sulfate, filtered and concentrated. The resulting material was purified by column chromatography on silica gel, using 30% ethyl acetate in hexanes as the eluent to yield the desired product (0.090 g, 23.4% based on starting 4-Bromo-5-methoxy-2-(4-methoxyphenyl)-benzofuran from two runs) as a tan powder: Mp. 221–222° C.; 1H NMR (DMSO-d6) δ 9.81 (s, 1 H), 8.94 (s, 1 H), ) 7.70 (d, 2 H, J=8.6 Hz), 7.16 (d, 1 H, J=8.9 Hz), 7.14 (s, 1 H), 6.86 (d, 2 H, J=8.6 Hz), 6.72 (d, 1 H, J=8.6 Hz), 2.27 (s, 3 H); MS 241 (M+H)+.

1. customThe layers were separated
2. extractionthe aqueous layer was extracted with ethyl acetate (2×)
3. washThe combined organics was washed with 1 N HCl (1×), water (1×)
4. dry with materialdried over magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated
7. customThe resulting material was purified by column chromatography on silica gel