6-Amino-3-chloropyridazine → 3-Amino-4-bromo-6-chloropyridazine

Participants

Reaction Steps

To a solution of 6-chloropyridazin-3-amine (16 g, 0.124 mol, Preparation #25) in methanol (200 mL) was added NaHCO3 (20.84 g, 0.24 mols). The reaction mixture was stirred for 30 min at RT and bromine (19.6 g, 0.124 mol, Spectrochem) added drop wise. Then reaction mixture was stirred for another 16 h and concentrated under vacuum. Crude material obtained was purified using silica gel column chromatography by eluting with 50% EtOAc in hexane to afford 4-bromo-6-chloropyridazin-3-amine 12 g (46%) as brown solid. 1H NMR (400 MHz, DMSO) δ 7.548 (s, 1H), 5.341 (br s, 2H); MS m/z=208.0 M+H+;

Provenance & Evidence