Hydrochloric Acid → 5-Bromopyridine-2,3-diamine

Participants

Reaction Steps

A mixture of 2-amino-5-bromo-3-nitropyridine (62.2 g, 285 mmol), iron powder (171 g, 3.06 mol), concentrated hydrochloric acid (2.85 ml), water (60 ml) and ethanol (230 ml) was refluxed for 2 h, filtered whilst warm, the solids washed twice with ethanol (2×150 ml) and the combined ethanol solutions were evaporated to dryness. The crude solid was recrystallized from water, using decolourising charcoal, filtered whilst warm, the solids washed twice with warm ethanol (2×100 ml), the ethanol evaporated off and the precipitate was filtered off, washed with water (3×75 ml) and dried to afford the title compound (27 g, 50%).

Provenance & Evidence