methyl 2-amino-4,5-difluorobenzoate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Methyl 4,5-difluoroanthranilate (0.19 g, 1 mmol) in THF (1.5 ml) was added at ca. 0° C. to p-nitrophenyl chloroformate (0.21 g, 1.05 mmol) in pyridine (0.089 ml, 1.1 mmol) and dry acetonitrile (2.0 ml). The mixture was stirred at r.t. for 2 h. Solvent was removed in vacuo, and the residue triturated with ethyl ether (ca. 3 ml), filtered, washed with ether (2×2 ml), water (3×3 ml), hexanes (3×5 ml), and dried in vacuo. Yield 0.27 g (77%). 1H NMR in CDCl3 (δ,ppm): 3.98 (s, 3 H), 7.40 (d, J=8.1 Hz, 2 H), 7.90 (m, 1 H), 8.30 (d, J 8.1 Hz, 2 H), 8.38 (m, 1 H), 11.07 (s, 1 H). Solvent was removed in vacuo the residue triturated with ethyl ether (ca. 3 ml) filtered washed with ether (2×2 ml), water (3×3 ml), hexanes (3×5 ml) dried in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Methyl 4,5-difluoroanthranilate (0.19 g, 1 mmol) in THF (1.5 ml) was added at ca. 0° C. to p-nitrophenyl chloroformate (0.21 g, 1.05 mmol) in pyridine (0.089 ml, 1.1 mmol) and dry acetonitrile (2.0 ml). The mixture was stirred at r.t. for 2 h. Solvent was removed in vacuo, and the residue triturated with ethyl ether (ca. 3 ml), filtered, washed with ether (2×2 ml), water (3×3 ml), hexanes (3×5 ml), and dried in vacuo. Yield 0.27 g (77%). 1H NMR in CDCl3 (δ,ppm): 3.98 (s, 3 H), 7.40 (d, J=8.1 Hz, 2 H), 7.90 (m, 1 H), 8.30 (d, J 8.1 Hz, 2 H), 8.38 (m, 1 H), 11.07 (s, 1 H). Solvent was removed in vacuo the residue triturated with ethyl ether (ca. 3 ml) filtered washed with ether (2×2 ml), water (3×3 ml), hexanes (3×5 ml) dried in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Methyl 4,5-difluoroanthranilate (0.19 g, 1 mmol) in THF (1.5 ml) was added at ca. 0° C. to p-nitrophenyl chloroformate (0.21 g, 1.05 mmol) in pyridine (0.089 ml, 1.1 mmol) and dry acetonitrile (2.0 ml). The mixture was stirred at r.t. for 2 h. Solvent was removed in vacuo, and the residue triturated with ethyl ether (ca. 3 ml), filtered, washed with ether (2×2 ml), water (3×3 ml), hexanes (3×5 ml), and dried in vacuo. Yield 0.27 g (77%). 1H NMR in CDCl3 (δ,ppm): 3.98 (s, 3 H), 7.40 (d, J=8.1 Hz, 2 H), 7.90 (m, 1 H), 8.30 (d, J 8.1 Hz, 2 H), 8.38 (m, 1 H), 11.07 (s, 1 H). Solvent was removed in vacuo the residue triturated with ethyl ether (ca. 3 ml) filtered washed with ether (2×2 ml), water (3×3 ml), hexanes (3×5 ml) dried in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of methyl 4,5-difluoro-2-nitrobenzoate 1b (23.0 g, 106 mmol) in EtOAc (200 mL), was added 10% Pd/C (wet, 50% water, 6.0 g), and the mixture was shaken on a Parr hydrogenator at 50 PSI for 3 hr. The reaction mixture was then filtered through a celite pad and the filtrate was concentrated by rotary evaporation to yield methyl 2-amino-4,5-difluorobenzoate 1c as a colorless solid, 19.0 g (96%). The reaction mixture was then filtered through a celite pad the filtrate was concentrated by rotary evaporation