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

Temperature

80 °C

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%).

1. temperaturewas cooled with ice
2. additionAfter the dropwise addition
3. additionThe reaction mixture was poured onto ice
4. extractionextracted with ethyl acetate-tetrahydrofuran (3:1
5. filtrationv/v) (at that time, insolubles were filtered off
6. dry with materialThe organic layer was dried over MgSO4
7. distillationthe solvent was distilled off under reduced pressure, and crystals
8. filtrationwere collected by filtration

ORD record

ord-21a4ae8fce1045958a0c46c001479522

Source dataset

uspto-grants-2009_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07622479B2