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

Participants

Reaction Conditions

Reaction Steps

A suspension of 2-amino-5-bromo-3-nitropyridine (21.0 g), iron filings (26.9 g) and ethanol (150 ml) was cooled with ice, and to the suspension was added dropwise concentrated hydrochloric acid (20 ml). After the dropwise addition, the mixture was stirred at room temperature for 10 minutes and at 80° C. for 50 minutes. The reaction mixture was poured onto ice, neutralized with 8 N sodium hydroxide, and extracted with ethyl acetate-tetrahydrofuran (3:1, v/v) (at that time, insolubles were filtered off by using celite). The organic layer was dried over MgSO4, the solvent was distilled off under reduced pressure, and crystals were collected by filtration to obtain 2,3-diamino-5-bromopyridine (15.8 g, 87%).

Provenance & Evidence