5-(4-Bromophenyl)furfural

brown powder

General procedure: 1.00 mmol arylhalide, 1.30 mmol furfural-boronic acid and 0.05 mmolBis(triphenylphosphine)palladium(II) dichloride were treated with 0.30 mLdimethoxyethane, 0.50 mL ethanol and 0.30 mL aqueous 2M sodium carbonate solution.The reaction was heated to 65°C for 1h or until the TLC showed no remaining startingmaterial. The mixture was evaporated and extracted three times with ethyl acetate. Thecombined organic layers were washed with brine, dried over MgSO4, filtered andconcentrated. The crude product was purified by column chromatography usinghexanes/ethyl acetate (9:1).General procedure: Method A: To a solution of 3a (150 mg, 0.47 mmol) in a mixture of dry DME (3 mL) and dry EtOH (3 mL), bis(triphenylphosphine)palladium(II) dichloride (17 mg, 0.02 mmol) was added. After 30 min, a solution of sodium carbonate (299 mg, 2.82 mmol) in H2O(2 mL) and a solution of 5-formyl-2-furanylboronic acid 4 (93 mg, 0.66 mmol) in dry EtOH (1.5 mL) were added in this order. The reaction was heated under reflux for 12 h. After this time, H2O (4 mL)was added at 25 C and the organic phase was extracted with EtOAc(3 5 mL), dried over sodium sulfate, filtered and evaporated in vacuo. The crude product was purified by flash chromatography on silica gel (2percent EtOAc in petroleum ether) to give 5a as orange solid(79 mg, 60percent). Method B: To a suspension of 16a (1.0 g, 4.8 mmol) in H2O (20 mL), HCl (37percent, 2 mL) was added. The resulting solution was cooled at 0 C and a solution of sodium nitrite (397 mg, 5.76 mmol) in H2O (2 mL) was added dropwise. After 1 h, a solution of 17(400 mL, 4.8 mmol) in acetone (2 mL) and solid copper(II) chloride(128 mg, 0.96 mmol) were added. The mixture kept at 25 C for 12 h. EtOAc was added (3 10 mL) and the organic phase was separated, dried over sodium sulfate, filtered and evaporated in vacuo. The crude product was purified by flash chromatography on silica gel (2percent EtOAc in petroleum ether) to give 5a as orange solid(1.23 g, 90percent).To a glass flask, 3 (113.8 mg, 0.650mmol), (4-bromophenyl)boronic acid (143.6 mg, 0.715 mmol), tetrabutylammonium bromide(209.6 mg, 0.650 mmol), Pd(OAc)2 (2.9 mg, 0.013 mmol) and K2CO3 (224.6 mg, 1.63 mmol)were added and then dissolved in deionized water (3 mL). The reaction mixture was stirred vigorously for 5 h at room temperature. After the white reaction mixture had become yellowand non-homogeneous, the mixture was diluted with water (10 mL), and the product was extracted with EtOAc. The organics were separated, filtered through a Celite pad, and dried with MgSO4. The organic solvent was removed under reduced pressure and the crude product was purified by dry-flash chromatography (SiO2: hexane/EtOAc = 9/1 to 7/3) to afford the title compound 5 (11 mg, 7 percent).

Molecular Weight:251.08
XLogP3:3.1
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:2
Exact Mass:249.96294
Monoisotopic Mass:249.96294
Topological Polar Surface Area:30.2
Heavy Atom Count:14
Complexity:200
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes