3-Amino-5-bromopyridine

28733-43-9

13535-01-8

General procedure for the synthesis of 5-bromo-3-aminopyridine from 5-bromonicotinamide: 1. To a pre-cooled 340 ml aqueous solution containing 31.8 g (0.79 mol) of sodium hydroxide and 40.7 g (0.255 mol) of bromine, 42.0 g (0.209 mol) of commercially available 5-bromonicotinamide was added. 2. The reaction mixture was gradually warmed to room temperature, followed by heating the reaction at 70 °C for 1 hour. 3. Upon completion of the reaction, the resulting brown suspension was allowed to cool to room temperature. 4. The aqueous phase was treated with saturated brine and then extracted three times with a 1:1 solvent mixture of THF and tert-butyl methyl ether. 5. The organic phases were combined, dried with magnesium sulfate, filtered and concentrated under reduced pressure. 6. 39.1 g of the dark brown residue obtained from the concentration was purified by fast chromatography (eluent: heptane/ethyl acetate 1:1) to yield 5-bromo-3-aminopyridine as a brown solid (total yield 70.2 g, 70% yield).