Ammonia → 2-Amino-4,6-difluorobenzamide

Participants

Reaction Steps

To a solution of 2-amino-4,6-difluoro benzoic acid (4.0 g, 23.12 mmol, Butt Park Ltd.) in tetrahydrofuran (1.0 L) and N,N-dimethylacetamide (150 mL) was added EDCl.HCl (13.44 g, 70 mmol, Aldrich), HOBT (9.5 g, 70 mmol, Aldrich) and ammonia as a 0.5M solution in dioxanes (460 mL, 230 mmol, Aldrich). 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-4,6-difluorobenzamide as a white crystalline solid (3.11 g, 78% yield); 1H NMR (400 MHz, DMSO-d6) δ ppm 6.21-6.27 (m, 1 H), 6.27-6.32 (m, 1 H), 6.52 (s, 2 H), 7.48 (s, 1 H), 7.53 (s, 1 H).

Provenance & Evidence