N-bromobutanimide → 4-Bromo-3-chloro-5-fluoroaniline

Participants

Reaction Conditions

Reaction Steps

3-Chloro-5-fluoroaniline (2061 mmol, 300 g) was dissolved in ACN (3000 ml) and the solution cooled to 0° C. NBS (2061 mmol, 367 g) was added to the reaction mixture in small portions keeping the temperature below 10° C. Reaction mixture was stirred at 10±5° C. for 3.5 h. 10% Aqueous NaHSO3 was added and the reaction mixture was concentrated under vacuum to remove organic solvents. Water and DCM was added, stirred for 15 min and the phases were separated. The water phase was extracted with DCM. The combined organics were washed with water. The organic phase was evaporated. 2-Propanol was added to the residue and distilled until the steam temperature was 80° C. Water was added and the temperature was kept at 40±10° C. The mixture was cooled to 5° C. and stirred for 4 h. The precipitate was removed by filtration, washed with water and dried under vacuum. 440.7 g of the title compound was obtained. 1H-NMR (400 MHz, DMSO-d6): δ 5.87 (s, 2H), 6.42-6.49 (m, 1H), 6.62-6.66 (m, 1H).

Provenance & Evidence