6-Bromobenzofuran

Light Yellow Oil

Polyphosphoric acid (PPA) (0.743 g, 6.83 mmol) was added to asolution of 175 (0.656 g, 2.28 mmol) in toluene (4.6 mL) at roomtemperature under Ar. The mixture was headed until reflux began, this being maintained for 4 h, then cooled to room temperature, quenched with cooled H2O and extracted with EtOAc. The organiclayers were washed with brine, dried (MgSO4), filtered and concentratedin vacuo. The crude product was purified by silica gel CC(EtOAc/hexane, 2:98) to give 6-bromobenzofuran (176) (major, 0.206 g, 1.05 mmol, 46percent) and 4-bromobenzofuran (177) (minor, 0.183 g, 0.935 mmol, 41percent) as colorless oils: 176: 1H-NMR (CDCl3, 400 MHz) d: 1H-NMR (CDCl3, 400 MHz) d: 6.75 (d, J = 1.6 Hz, 1H, furan-H), 7.36 (dd, J = 1.2, 8.4 Hz, 1H, Ar–H), 7.46 (d, J = 8.4 Hz, 1H, Ar–H), 7.60 (d, J = 1.6 Hz, 1H, furan-H), 7.69 (s, 1H, Ar–H);177: 1H-NMR (CDCl3, 400 MHz) d: 6.82 (d, J = 2.4 Hz, 1H, furan-H), 7.17 (dd, J = 7.6, 8.4 Hz, Ar–H), 7.40 (d, J = 7.6 Hz, 1H, Ar–H), 7.45 (d, J = 8.4 Hz, 1H, Ar–H), 7.66 (d, J = 2.4 Hz, 1H, furan-H).A mixture of 17 gm (57.8 mMol) 2-(3-bromophenoxy)acetaldehyde diethyl acetal and 17.5 gm polyphosphoric acid in 400 mL chlorobenzene was heated to 80° C. for 2 hours. The reaction mixture was cooled to room temperature and the chlorobenzene was decanted from the polyphosphoric acid. The polyphosphoric acid was washed with two 150 mL portions of diethyl ether. All or the organic phases were combined and concentrated under reduced pressure. The residue was redissolved in diethyl ether and the organic phases were washed with saturated aqueous sodium bicarbonate, water, and saturated aqueous sodium chloride, dried over magnesium sulfate and concentrated under reduced pressure. The residual oil was subjected to silica gel chromatography, eluting with hexane.Fractions containing the faster eluting isomer were combined and concentrated under reduced pressure to provide 1.7 gm (15percent) 4-bromobenzofuran.EA: Calculated for CA mixture of 17 gm (57.8 mMol) 2-(3-bromophenoxy)acetaldehyde diethyl acetal and 17.5 gm polyphosphoric acid in 400 mL chlorobenzene was heated to 80°C for 2 hours. The reaction mixture was cooled to room temperature and the chlorobenzene was decanted from the polyphosphoric acid. The polyphosphoric acid was washed with two 150 mL portions of diethyl ether. All or the organic phases were combined and concentrated under reduced pressure. The residue was redissolved in diethyl ether and the organic phases were washed with saturated aqueous sodium bicarbonate, water, and saturated aqueous sodium chloride, dried over magnesium sulfate and concentrated under reduced pressure. The residual oil was subjected to silica gel chromatography, eluting with hexane. Fractions containing the faster eluting isomer were combined and concentrated under reduced pressure to provide 1.7 gm (15percent) 4-bromobenzofuran. EA: Calculated for C8H5BrO: Theory: C, 48.77; H, 2.56. Found: C, 48.89; H, 2.72. Fractions containing the slower eluting isomer were combined and concentrated under reduced pressure to provide 2.5 gm (22percent) 6-bromobenzofuran. EA: Calculated for C8H5BrO: Theory: C, 48.77; H, 2.56. Found: C, 48.89; H, 2.67.1) In a dry 500mL three-necked flask, add 3-bromoaniline (17.20g, 100mmol) and To a solution of 6-bromo- l-benzofuran (30 g) in tetrahydrofuran (150 ml) was added sodium cyanide (22.83 g). Reaction mass was heated to reflux and reaction monitored by TLC. After completion of reaction, reaction mass was diluted with water and Ethyl acetate added to reaction mass. Layers were separated and organic layer was washed with water and brine solution. Organic layer was then separated and concentrated and residue so obtained was purified in column chromatography using ethyl acetate and hexane to get 1-benzofuran- (0181) 6- carbonitrile. (10.88 g, 50% yield)

Molecular Weight:197.03
XLogP3:3
Hydrogen Bond Acceptor Count:1
Exact Mass:195.95238
Monoisotopic Mass:195.95238
Topological Polar Surface Area:13.1
Heavy Atom Count:10
Complexity:126
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes