反应详情

To a solution of 2-amino-5,6-difluoro benzoic acid (3.78 g, 21.8 mmol) in tetrahydrofuran (500 mL) was added EDCl.HCl (8.5 g, 44.0 mmol, 2.0 equiv.), HOBT (5.9 g, 44 mmol, 2.0 equiv.) and ammonia as a 0.5M solution in dioxanes (218 mL, 109 mmol, 5 equiv.). The resultant slurry was stirred for 24 hours, and then solids removed by filtration through celite. The filtrate was taken to a residue under reduced pressure and partitioned between water and ethyl acetate. The organic layer was dried over sodium sulfate, filtered, taken to a residue under reduced pressure, and purified by chromatography on SiO2 (Ethyl acetate/Hexanes) to afford analytically pure 2-amino-5,6-difluorobenzamide as a white crystalline solid (2.73 g, 15.8 mmol, 72% Yield). 1H NMR (400 MHz, DMSO-d6) δ ppm 5.78 (s, 2 H), 6.45 (ddd, J=9.16, 4.03, 1.83 Hz, 1 H), 7.10-7.18 (m, 1 H), 7.69 (d, J=11.00 Hz, 2 H).

1. customsolids removed by filtration through celite
2. custompartitioned between water and ethyl acetate
3. dry with materialThe organic layer was dried over sodium sulfate
4. filtrationfiltered
5. custompurified by chromatography on SiO2 (Ethyl acetate/Hexanes)