Dichloromethane → 2-Aminobiphenyl

Temperature

60 °C

A stirred solution of 2-bromo-5-chloronitrobenzene (5.00 g, 21.2 mmol) and phenylboronic acid (2.58 g, 21.2 mmol) in tetrahydrofuran (85 mL) was treated under nitrogen with [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium (II) complex with dichloromethane (0.52 g, 0.63 mmol, 3 mole %) and a 5 N sodium hydroxide solution (8.5 mL, 42.5 mmol). The reaction was heated at 60° C. for twelve hours, cooled to room temperature, and the solvent removed in vacuo. The residue was treated with ethyl acetate (200 mL) and a saturated aqueous sodium chloride solution (100 mL). The phases were separated and the aqueous phase was extracted with ethyl acetate (2×50 mL). The combined organic phase was dried over anhydrous magnesium sulfate, filtered, and the solvent concentrated in vacuo. The resulting brown oil was filtered through a plug of silica gel (20:80 ethyl acetate:hexane). After concentration of the solvent in vacuo, the resulting, pure 4-chloro-2-nitro-biphenyl (4.66 g, 19.0 mmol, 94%) was dissolved in acetic acid (13.2 mL) and ethanol (13.2 mL). Iron granules (15.6 g, 278 mmol) were added and the mixture was stirred with a mechanical stirrer for 12 hours. The mixture was diluted with ethanol and then filtered through Celite® filter aid. The resulting solution was concentrated in vacuo, diluted with toluene and concentrated in vacuo (×3) to afford a viscous oil. The viscous oil was purified by flash column chromatography, eluting with a mixture of ethyl acetate-hexane (1:4), to afford the title compound as a homogeneous oil (3.46 g, 85%);

1. temperaturecooled to room temperature
2. customthe solvent removed in vacuo
3. additionThe residue was treated with ethyl acetate (200 mL)
4. customThe phases were separated
5. extractionthe aqueous phase was extracted with ethyl acetate (2×50 mL)
6. dry with materialThe combined organic phase was dried over anhydrous magnesium sulfate
7. filtrationfiltered
8. concentrationthe solvent concentrated in vacuo
9. filtrationThe resulting brown oil was filtered through a plug of silica gel (20:80 ethyl acetate:hexane)
10. filtrationfiltered through Celite®
11. filtrationfilter aid
12. concentrationThe resulting solution was concentrated in vacuo
13. additiondiluted with toluene
14. concentrationconcentrated in vacuo (×3)
15. customto afford a viscous oil
16. customThe viscous oil was purified by flash column chromatography
17. washeluting with a mixture of ethyl acetate-hexane (1:4)

ORD record

ord-1b02d17c747844e2872a25e486bec80c

Source dataset

uspto-grants-2005_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06894061B2