反应详情

2-(2-Methoxy-3-nitro-phenyl)-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane 4d (10 g, 35.85 mmol), 5-bromofuran-2-carboxylic acid (5.47 g, 28.66 mmol), tetrakis(triphenylphosphine)palladium (2.07 g, 1.79 mmol) and sodium carbonate (7.60 g, 71.66 mmol) were dissolved in the solvent mixture of 200 mL of 1,4-dioxane and 30 mL of water. The reaction mixture was heated to reflux for 2.5 hours. The mixture was filtered and the filtrate was concentrated under reduced pressure. The residue was diluted with 150 mL of water and adjusted to pH 3 with 1 M hydrochloric acid. Then the mixture was filtered and the filter cake was washed with 50 mL of the solvent mixture of n-hexane/ethyl acetate (V/V=1:1). The residue was dried to obtain the title compound 5-(2-methoxy-3-nitro-phenyl) furan-2-carboxylic acid 4e (4.23 g, yield 56.1%) as a grey solid.

1. temperatureThe reaction mixture was heated
2. temperatureto reflux for 2.5 hours
3. filtrationThe mixture was filtered
4. concentrationthe filtrate was concentrated under reduced pressure
5. additionThe residue was diluted with 150 mL of water
6. filtrationThen the mixture was filtered
7. washthe filter cake was washed with 50 mL of the solvent mixture of n-hexane/ethyl acetate (V/V=1:1)
8. customThe residue was dried