7-bromo-8-fluoro-3,4-dihydro-2H-1-benzoxepin-5-one

Conditions: temp:-20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Into a 20-L 4-necked round-bottom flask purged and maintained with an inert atmosphere of argon was placed 7-Bromo-8-fluoro-3,4-dihydro-2H-benzo[b]oxepin-5-one (1168 g, 4.51 mol, 1.00 equiv) and dichloromethane (8 L), followed by the addition of Br2 (724.3 g, 4.53 mol, 1.00 equiv) dropwise with stirring at −20° C. over 90 min. The resulting solution was stirred at −20° C. for 30 min and at room temperature for 3 h. The reaction was then quenched by the addition of 6000 mL of saturated aqueous Na2SO3 at 0° C. and extracted with 4×2 L of dichloromethane. The combined organic layers were washed with 2×3000 mL of brine, dried over anhydrous sodium sulfate and concentrated under vacuum to afford 1170 g (77%) of 4,7-dibromo-8-fluoro-2,3,4,5-tetrahydro-1-benzoxepin-5-one as a yellow solid. Into a 20-L 4-necked round-bottom flask purged maintained with an inert atmosphere of argon The resulting solution was stirred at −20° C. for 30 min and at room temperature for 3 h The reaction was then quenched by the addition of 6000 mL of saturated aqueous Na2SO3 at 0° C. extracted with 4×2 L of dichloromethane The combined organic layers were washed with 2×3000 mL of brine dried over anhydrous sodium sulfate concentrated under vacuum

Conditions: temp:-20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Into a 20-L 4-necked round-bottom flask purged and maintained with an inert atmosphere of argon was placed 7-Bromo-8-fluoro-3,4-dihydro-2H-benzo[b]oxepin-5-one (1168 g, 4.51 mol, 1.00 equiv) and dichloromethane (8 L), followed by the addition of Br2 (724.3 g, 4.53 mol, 1.00 equiv) dropwise with stirring at −20° C. over 90 min. The resulting solution was stirred at −20° C. for 30 min and at room temperature for 3 h. The reaction was then quenched by the addition of 6000 mL of saturated aqueous Na2SO3 at 0° C. and extracted with 4×2 L of dichloromethane. The combined organic layers were washed with 2×3000 mL of brine, dried over anhydrous sodium sulfate and concentrated under vacuum to afford 1170 g (77%) of 4,7-dibromo-8-fluoro-2,3,4,5-tetrahydro-1-benzoxepin-5-one as a yellow solid. Into a 20-L 4-necked round-bottom flask purged maintained with an inert atmosphere of argon The resulting solution was stirred at −20° C. for 30 min and at room temperature for 3 h The reaction was then quenched by the addition of 6000 mL of saturated aqueous Na2SO3 at 0° C. extracted with 4×2 L of dichloromethane The combined organic layers were washed with 2×3000 mL of brine dried over anhydrous sodium sulfate concentrated under vacuum