反应详情

2-(2-Methoxy-3-nitro-phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane 6a (3.6 g, 12 mmol), 5-bromofuran-2-carboxylic acid methyl ester (2.05 g, 10 mmol), tetrakis(triphenylphosphine)palladium (1.55 g, 0.5 mmol) and sodium carbonate (2.12 g, 20 mmol) were dissolved in 1,4-dioxane. The reaction mixture was heated to reflux for 3 hours. The reaction was monitored by TLC until the disappearance of the starting materials. The mixture was filtered and the filtrate was concentrated under reduced pressure. The residue was diluted with 30 mL of water and 50 mL of ethyl acetate. The separated organic layer was concentrated under reduced pressure and recrystallized from a solvent mixture of ethyl acetate and n-hexane to obtain the title compound 5-(2-methoxy-3-nitro-phenyl)-furan-2-carboxylic acid methyl ester 54a (500 mg, yield 18%) as a yellow solid.

1. temperatureThe reaction mixture was heated
2. temperatureto reflux for 3 hours
3. filtrationThe mixture was filtered
4. concentrationthe filtrate was concentrated under reduced pressure
5. additionThe residue was diluted with 30 mL of water and 50 mL of ethyl acetate
6. concentrationThe separated organic layer was concentrated under reduced pressure
7. customrecrystallized from a solvent mixture of ethyl acetate and n-hexane