反应详情

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).

1. concentrationthe solution was concentrated in vacuo
2. additiondiluted with ethyl acetate
3. washThe organic layer was washed successively with aq 2 N HCl and saturated aq NaCl
4. dry with materialdried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated
7. customPurification by MPLC (10–100% ethyl acetate in heptane, 23 mL/min, 75 min)