反应详情

To a solution of ethyl-3-aminobenzoate (50 mL, 333 mmol) and 2,6-difluorobenzenesulfonyl chloride (44.2 mL, 333 mmol) in DCM (300 mL) at 0° C. was added pyridine (32.2 mL, 400 mmol). The reaction mixture was warmed to rt, stirred for 36 h, and quenched with 2 mL NH3 (7M in MeOH). The suspension washed with 10% NaHSO4 and the organic extracts combined and passed through a short column of silica gel. Residual material was flushed from the column with 10% MeOH/EtOAc. The organic extracts were combined and the solvent removed under reduced pressure to provide 107.9 g (95%) of the title compound of Step A. 1H-NMR (400 MHz, DMSO-d6) δ ppm 11.20 (s, 1H), 7.77 (s, 1H), 7.71 (t, J=7.4 Hz, 1H), 7.63 (d, J=7.3 Hz, 1H), 7.35-7.49 (m, 2H), 7.29 (t, J=9.3 Hz, 2H), 4.28 (q, J=7.1 Hz, 2H), and 1.29 (t, J=7.1 Hz, 3H).

1. customquenched with 2 mL NH3 (7M in MeOH)
2. washThe suspension washed with 10% NaHSO4
3. customResidual material was flushed from the column with 10% MeOH/EtOAc
4. customthe solvent removed under reduced pressure