Bromine → 4-Bromo-6-chloro-5-phenylpyridazin-3-amine

Participants

Reaction Steps

To a suspension of 6-chloro-5-phenylpyridazin-3-amine (1.01 g, 4.9 mmol) from 1a in methanol (25 mL) under nitrogen was added NaHCO3 (1.09 g, 13.0 mmol). At 0° C., bromine (0.55 M in methanol, 10 mL, 5.5 mmol) was added over 5 min. After 1 h, the cold bath was removed, and the reaction mixture was stirred at room temperature for 6 h. After concentrating in vacuo, the residue was taken up in CH2Cl2 and saturated aqueous Na2S2O5, and the layers were separated. The organic layer was washed with saturated aqueous NaHCO3 and brine, dried over Na2SO4, filtered, and concentrated in vacuo to give crude 4-bromo-6-chloro-5-phenylpyridazin-3-amine (1.28 g).

Provenance & Evidence