2,5-difluoro-4-iodoaniline

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

Procedure: To a solution of 2,5-difluoro-4-iodoaniline (5.3 g, 19.4 mmol, Can. J. Chem., 2000(78), 1081-1088) in DCM (50 ml) was added methanesulfonyl chloride (1.65 ml, 21.3 mmol) and pyridine (4.7 ml, 58.2 mmol) at 0° C. The mixture was stirred for 24 hours at room temperature. The mixture was partitioned between EtOAc and 2 M HCl aqueous solution. The organic layer was separated and washed with 2 M aqueous HCl solution and brine, dried over sodium sulfate and concentrated in vacuo. The crude product was purified by silica gel column chromatography eluting with gradually from hexane/EtOAc (4:1) to hexane/EtOAc (3:1) to give the title compound (5.6 g, 87%) as purple solids. The mixture was partitioned between EtOAc and 2 M HCl aqueous solution The organic layer was separated washed with 2 M aqueous HCl solution and brine dried over sodium sulfate concentrated in vacuo The crude product was purified by silica gel column chromatography eluting with gradually from hexane/EtOAc (4:1) to hexane/EtOAc (3:1)

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

Procedure: To a solution of 2,5-difluoro-4-iodoaniline (5.3 g, 19.4 mmol, Can. J. Chem., 2000(78), 1081-1088) in DCM (50 ml) was added methanesulfonyl chloride (1.65 ml, 21.3 mmol) and pyridine (4.7 ml, 58.2 mmol) at 0° C. The mixture was stirred for 24 hours at room temperature. The mixture was partitioned between EtOAc and 2 M HCl aqueous solution. The organic layer was separated and washed with 2 M aqueous HCl solution and brine, dried over sodium sulfate and concentrated in vacuo. The crude product was purified by silica gel column chromatography eluting with gradually from hexane/EtOAc (4:1) to hexane/EtOAc (3:1) to give the title compound (5.6 g, 87%) as purple solids. The mixture was partitioned between EtOAc and 2 M HCl aqueous solution The organic layer was separated washed with 2 M aqueous HCl solution and brine dried over sodium sulfate concentrated in vacuo The crude product was purified by silica gel column chromatography eluting with gradually from hexane/EtOAc (4:1) to hexane/EtOAc (3:1)

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

Procedure: 2,5-Difluoroaniline (38 g) was dissolved in acetic acid (120 ml), and then pyridine (25 g) was added thereto, followed by stirring. A mixed solution of iodine monochloride (50 g) with acetic acid (30 ml) was added dropwise thereto. After stirring at room temperature for 1 hour, the mixed solution was further stirred at 70° to 80° C. for 2 hours. Then, the reaction solution was poured into water, and the precipitated crystals were filtered, followed by washing with water. The resulting crystals were dissolved in chloroform, and then washed with water twice, further with 10% potassium hydroxide aqueous solution twice, and furthermore with water twice, followed by distilled off chloroform therefrom. The residue was distilled under reduced pressure (b.p. 130° to 140° C./20 mmHg), and then recrystallized from methanol, to give 4-iodo-2,5-difluoroaniline (50 g). After stirring at room temperature for 1 hour the mixed solution was further stirred at 70° to 80° C. for 2 hours the precipitated crystals were filtered by washing with water The resulting crystals were dissolved in chloroform washed with water twice by distilled off chloroform The residue was distilled under reduced pressure (b.p. 130° to 140° C./20 mmHg) recrystallized from methanol

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

Procedure: To a solution of 2,5-difluoro-4-iodoaniline (5.3 g, 19.4 mmol, Can. J. Chem., 2000(78), 1081-1088) in DCM(50 ml) was added methanesulfonyl chloride (1.65 ml, 21.3 mmol) and pyridine (4.7 ml, 58.2 mmol) at 0° C. The mixture was stirred for 24 hours at room temperature. The mixture was partitionedbetween EtOAc and 2 M HCl aqueous solution. The organic layer was separated and washed with 2 M aqueous HCl solution and brine, dried over sodium sulfate and concentrated in vacuo. The crude puroduct was purified by silica gel column chromatography eluting with gradually from hexane/EtOAc (4:1) to hexane/EtOAc (3:1) to give the title compound (5.6 g, 87%) as purple solids. The organic layer was separated washed with 2 M aqueous HCl solution and brine dried over sodium sulfate concentrated in vacuo The crude puroduct was purified by silica gel column chromatography eluting with gradually from hexane/EtOAc (4:1) to hexane/EtOAc (3:1)

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

Procedure: To a solution of 2,5-difluoro-4-iodoaniline (5.3 g, 19.4 mmol, Can. J. Chem., 2000(78), 1081-1088) in DCM (50 ml) was added methanesulfonyl chloride (1.65 ml, 21.3 mmol) and pyridine (4.7 ml, 58.2 mmol) at 0° C. The mixture was stirred for 24 hours at room temperature. The mixture was partitioned between EtOAc and 2 M HCl aqueous solution. The organic layer was separated and washed with 2 M aqueous HCl solution and brine, dried over sodium sulfate and concentrated in vacuo. The crude product was purified by silica gel column chromatography eluting with gradually from hexane/EtOAc (4:1) to hexane/EtOAc (3:1) to give the title compound (5.6 g, 87%) as purple solids. The mixture was partitioned between EtOAc and 2 M HCl aqueous solution The organic layer was separated washed with 2 M aqueous HCl solution and brine dried over sodium sulfate concentrated in vacuo The crude product was purified by silica gel column chromatography eluting with gradually from hexane/EtOAc (4:1) to hexane/EtOAc (3:1)