反应详情

But-2-ynyl bromide (0.29 mL, 3.4 mmol) was added to a suspension of 4-difluoromethoxy-3-hydroxybenzaldehyde (0.43 g, 2.3 mmol) and potassium carbonate (0.95 g, 6.9 mmol) in acetonitrile (5 mL). The suspension was heated to reflux for 16 h and then concentrated under reduced pressure. Water was added and the aqueous phase was extracted with EtOAc. The combined organic fractions were washed with water, brine, dried. The product was concentrated under reduced pressure providing 3-(but-2-ynyloxy)-4-difluoromethoxybenzaldehyde (0.53 g, 97%) as a yellow crystalline solid; mp 46-47° C.; δH (500 MHz, CDCl3) 1.86 (t, J=2.5 Hz, 3H, C≡CCH3), 4.81 (q, J=2.5 Hz, 2H, OCH2), 6.68 (t, J=72.0 Hz, 1H, CHF2), 7.33 (d, J5,6=8.0 Hz, 1H, H5), 7.50 (dd, J5,6=8.0, J2,6=2.0 Hz, 1H, H6), 7.63 (d, J2,6=2.0 Hz, 1H, H2), 9.96 (s, 1H, CHO); δC (125 MHz, CDCl3) 3.7, 57.5, 72.7, 85.3, 113.4, 115.6 (t, J=256 Hz), 121.8, 125.1, 134.4, 145.3, 149.7, 190.7; νmax 1123, 1268, 1435, 1505, 1597, 1698, 2858 cm−1.

1. temperatureThe suspension was heated
2. temperatureto reflux for 16 h
3. concentrationconcentrated under reduced pressure
4. additionWater was added
5. extractionthe aqueous phase was extracted with EtOAc
6. washThe combined organic fractions were washed with water, brine
7. customdried
8. concentrationThe product was concentrated under reduced pressure