Boron tribromide → 6-Fluoro-4-hydroxy-biphenyl-3-carboxylic acid 3-nitro-benzylamide

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A stirring solution of 6-fluoro-4-methoxy-biphenyl-3-carboxylic acid 3-nitro-benzylamide (2.18 g, 5.7 mmol) in dichloromethane (150 mL, 0.4 M) at −78° C. was treated with BBr3 (27 mL, 27 mmol). The mixture was allowed to stir for 45 min at −78° C. and was then quenched with 100 mL of methanol. The mixture was allowed to warm to room temperature, concentrated, and filtered through a plug of silica gel using 50% ethyl acetate as the eluant. The filtrate was concentrated to provide 6-fluoro-4-hydroxy-biphenyl-3-carboxylic acid 3-nitro-benzylamide (2.1 g, 100%) as a yellow powder: Rf 0.68 (50% ethyl acetate in heptane); 1H NMR (CDCl3, 300 MHz) δ 12.29 (bd s, 1 H), 8.14–8.09 (m, 2 H), 7.65 (d, J=7.2 Hz, 1 H), 7.48 (t, J=8.0 Hz, 1H), 7.38–7.29 (m, 5H), 6.74 (d, J=11.4 Hz, 1 H), 6.60 (bd s, 1H), 4.68 (d, J=6.0 Hz, 2H).

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