Diisopropylethylamine → 4-fluoro-2-hydroxy-N-(3-nitro-benzyl)-benzamide

Participants

Reaction Steps

A solution of 4-fluoro salicylic acid chloride (12.3 g, 70.3 mmol) in dichloromethane (140 mL) was cooled to 0° C., and treated with N,N-diisopropylethylamine (31.0 mL, 175 mmol) and 3-nitrobenzylamine hydrochloride (16 g, 84.6 mmol). After stirring at room temperature for 24 h, the solution was concentrated in vacuo and diluted with ethyl acetate. The organic layer was washed successively with aq 2 N HCl and saturated aq NaCl, dried over MgSO4, filtered and concentrated. Purification by MPLC (10–100% ethyl acetate in heptane, 23 mL/min, 75 min) provided 4-fluoro-2-hydroxy-N-(3-nitro-benzyl)-benzamide as a yellow solid (13.7 g, 67%): 1H NMR (DMSO-d6 300 MHz) δ 12.75 (s, 1 H), 9.43 (t, J=6.0 Hz, 1 H), 8.11 (ddd, J, =8.3, J2=2.1 Hz, J3=1.2 Hz, 1 H), 8.18 (t, J=1.5 Hz, 1 H), 7.94 (dd, J1=8.9 Hz, J2=6.5 Hz, 1 H), 7.78 (td, J1=7.8 Hz, J2=1.4 Hz, 1 H), 7.63 (t, J=8.0 Hz, 1 H), 6.81–6.72 (m, 2 H), 4.61 (d, J=5.7 Hz, 2 H).

Provenance & Evidence