tert-butyl N-(2,5-difluorophenyl)carbamate

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: nBuLi (5.67 mL, 14.2 mmol) was added to a solution of tert-butyl (2,5-difluorophenyl)carbamate (1.08 g, 4.73 mmol) and TMEDA (2.14 mL, 14.2 mmol) in THF (21.6 mL) at −78° C. over 20 minutes, ensuring the internal temperature remained below −70° C. The resulting solution was stirred at −78° C. for 1 h. Iodine (3.60 g, 14.2 mmol) in THF (10 mL) was added dropwise over 30 min, also ensuring the internal temperature remained below −70° C. The resulting reaction was stirred for 1 h at −78° C., The reaction was quenched at −78° C. with water and the reaction warmed to room temperature. 10% Sodium thiosulfate was added until the iodine color dissipated and the mixture was then extracted with ethyl acetate (3×50 mL). The combined organic fractions were dried (MgSO4), filtered and concentrated. The crude material was purified on silica gel, eluting 0-60% EtOAc in hexanes over 28 minutes to afford tert-butyl (3,6-difluoro-2-iodophenyl)carbamate (1.14 g, 3.20 mmol) as a white crystalline solid. MS (ESI): m/z=300.2 (M+H-[t-Bu]). remained below −70° C remained below −70° C The resulting reaction was stirred for 1 h at −78° C. The reaction was quenched at −78° C. with water the reaction warmed to room temperature 10% Sodium thiosulfate was added until the iodine color the mixture was then extracted with ethyl acetate (3×50 mL) The combined organic fractions were dried (MgSO4) filtered concentrated The crude material was purified on silica gel eluting 0-60% EtOAc in hexanes over 28 minutes

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

Procedure: Di-tert-butyl (2,5-difluorophenyl)imidodicarbonate (1.48 g, 4.49 mmol) was dissolved in DCM (15.0 mL) at rt. TFA (0.48 mL, 6.28 mmol) was added to the reaction and the contents were stirred for 1 h. LC/MS at this time shows that starting material has been consumed. The solution was then washed with saturated aqueous sodium bicarbonate. The organics were dried over MgSO4 filtered and concentrated. The crude product was purified on silica gel, eluting with 0-50% EtOAc in hexanes over 32 minutes to afford the title compound (758 mg, 2.88 mmol) as a pale yellow oil. MS (ESI): m/z=174.2 (M+H-[t-Bu]). has been consumed The solution was then washed with saturated aqueous sodium bicarbonate The organics were dried over MgSO4 filtered concentrated The crude product was purified on silica gel eluting with 0-50% EtOAc in hexanes over 32 minutes

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: nBuLi (5.67 mL, 14.2 mmol) was added to a solution of tert-butyl (2,5-difluorophenyl)carbamate (1.08 g, 4.73 mmol) and TMEDA (2.14 mL, 14.2 mmol) in THF (21.6 mL) at −78° C. over 20 minutes, ensuring the internal temperature remained below −70° C. The resulting solution was stirred at −78° C. for 1 h. Iodine (3.60 g, 14.2 mmol) in THF (10 mL) was added dropwise over 30 min, also ensuring the internal temperature remained below −70° C. The resulting reaction was stirred for 1 h at −78° C., The reaction was quenched at −78° C. with water and the reaction warmed to room temperature. 10% Sodium thiosulfate was added until the iodine color dissipated and the mixture was then extracted with ethyl acetate (3×50 mL). The combined organic fractions were dried (MgSO4), filtered and concentrated. The crude material was purified on silica gel, eluting 0-60% EtOAc in hexanes over 28 minutes to afford tert-butyl (3,6-difluoro-2-iodophenyl)carbamate (1.14 g, 3.20 mmol) as a white crystalline solid. MS (ESI): m/z=300.2 (M+H-[t-Bu]). remained below −70° C remained below −70° C The resulting reaction was stirred for 1 h at −78° C. The reaction was quenched at −78° C. with water the reaction warmed to room temperature 10% Sodium thiosulfate was added until the iodine color the mixture was then extracted with ethyl acetate (3×50 mL) The combined organic fractions were dried (MgSO4) filtered concentrated The crude material was purified on silica gel eluting 0-60% EtOAc in hexanes over 28 minutes

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

Procedure: Di-tert-butyl (2,5-difluorophenyl)imidodicarbonate (1.48 g, 4.49 mmol) was dissolved in DCM (15.0 mL) at rt. TFA (0.48 mL, 6.28 mmol) was added to the reaction and the contents were stirred for 1 h. LC/MS at this time shows that starting material has been consumed. The solution was then washed with saturated aqueous sodium bicarbonate. The organics were dried over MgSO4 filtered and concentrated. The crude product was purified on silica gel, eluting with 0-50% EtOAc in hexanes over 32 minutes to afford the title compound (758 mg, 2.88 mmol) as a pale yellow oil. MS (ESI): m/z=174.2 (M+H-[t-Bu]). has been consumed The solution was then washed with saturated aqueous sodium bicarbonate The organics were dried over MgSO4 filtered concentrated The crude product was purified on silica gel eluting with 0-50% EtOAc in hexanes over 32 minutes