Sodium Carbonate → 5-(2-Methoxy-3-nitro-phenyl)furan-2-carboxylic acid

Participants

Reaction Steps

2-(2-Methoxy-3-nitro-phenyl)-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane 6a (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 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 150 mL of water and adjusted to pH 3 with 1 N 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 9a (4.23 g, yield 56.1%) as a grey solid.

Provenance & Evidence