反应详情

温度

80 °C

A flask containing 4-bromo-5-nitrothiophene-2-carbaldehyde (1.00 g, 4.24 mmol), (1H-pyrazol-5-yl)boronic acid (510 mg, 4.56 mmol), ethyleneglycol dimethyl ether (20 mL), triethylamine (1.80 mL), water (2.00 mL) and bis(diphenylphosphino)ferrocene]dichloropalladium(II) complex with dichloromethane (340 mg, 0.42 mmol) was evacuated and purged with nitrogen twice, then heated at 80° C. under nitrogen for 4 h. The reaction was cooled to room temperature, poured into a saturated solution of ammonium chloride (20 mL), extracted with ethyl acetate (3×10 mL), combined organics washed with a saturated solution of ammonium chloride (30 mL), dried (Na2SO4) and concentrated under reduced pressure. The crude product was purified by flash chromatography, eluting with ethyl acetate in hexanes, to yield 5-nitro-4-(1H-pyrazol-3-yl)thiophene-2-carbaldehyde as a yellow oil (950 mg, 28%). 1H NMR (400 MHZ, DMSO-d6) δ 6.99 (s, 1H), 7.94 (s, 1H), 8.42 (s, 1H), 10.07 (s, 1H).

1. customwas evacuated
2. custompurged with nitrogen twice
3. temperatureThe reaction was cooled to room temperature
4. additionpoured into a saturated solution of ammonium chloride (20 mL)
5. extractionextracted with ethyl acetate (3×10 mL)
6. washcombined organics washed with a saturated solution of ammonium chloride (30 mL)
7. dry with materialdried (Na2SO4)
8. concentrationconcentrated under reduced pressure
9. customThe crude product was purified by flash chromatography
10. washeluting with ethyl acetate in hexanes