Sulfuric Acid → 2,6-Dibromo-3-nitropyridin-4-amine

Participants

Reaction Conditions

Reaction Steps

Concentrated sulphuric acid (250 ml) was heated in an oil bath until the temperature of the acid reached 47° C. 2,6-dibromo pyridin-4-yl-N-nitroamine (34.0 g, 114.5 mmol) was added in portions over 35 mins. The temperature of the mixture gradually rose throughout the addition period until it was 56° C. at the end. The mixture was stirred at 53-55° C. for 1 hour. Once the reaction was completed, the reaction mixture was cooled to in an ice-bath and poured on ˜2 L of crushed ice with stirring. The product precipitated and was filtered off. Combined with other batch 00110916-140-001 from an identical scale reaction. The crude, wet amino nitro pyridine was dissolved in 700 ml EtOAc and the water layer was separated. The organic layer was washed with water (2×150 ml), 1×150 ml aq. NaHCO3, brine (2×150 ml), dried (MgSO4) and concentrated under reduced pressure to give 28 g of the title compound.

Provenance & Evidence