2-Bromo-1-fluoro-4-nitrobenzene → 2-Fluoro-2'-methylthio-5-nitrobiphenyl

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 2-bromo-1-fluoro-4-nitrobenzene (5.89 g, 26.8 mmol), 2-(methylthio)benzeneboronic acid (5.62 g, 33.5 mmol) and potassium fluoride (5.13 g, 88.3 mmol) in tetrahydrofuran (70 ml) was degassed with nitrogen for 30 min. This mixture was then treated with tris(dibenzylideneacetone)dipalladium(0) (496 mg, 0.541 mmol) followed by tri-tert-butylphosphine (5.35 ml of a 0.2M solution in 1,4-dioxane, 1.07 mmol) and the reaction was degassed for a further 10 min. The resulting slurry was then heated at 50° C. for 16 h under nitrogen. After cooling, the reaction mixture was partitioned between ethyl acetate (300 ml) and water (300 ml). The organic layer was washed with brine (200 ml), dried over anhydrous sodium sulphate, filtered and evaporated. Purification by chromatography on silica gel eluting with isohexane on a gradient of ethyl acetate (5-10%) gave 2-fluoro-2′-methylthio-5-nitrobiphenyl as a pale yellow solid (6.95 g, 99%): δH (360 MHz, CDCl3) 2.42 (3H, s), 7.21-7.32 (3H, m), 7.37 (1H, d, J 7), 7.44 (1H, td, J 8 and 2), 8.27-8.31 (2H, m).

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