Ethyl Acetate → 5-Bromopyridine-2,3-diamine

Temperature

60 °C

Commercially-available 5-bromo-3-nitro-pyridin-2-ylamine (20.0g, 92 mmol) was suspended in a 9:1 ethyl acetate:t-BuOH solution (470 ml). Tin chloride dihydrate (104 g, 460 mmol) was added, and the suspension was stirred under nitrogen for 2 h at 60° C. NaBH4 (1.75 g, 46 mmol) was added slowly, and the suspension was allowed to stir for another 3 hours. The reaction mixture was then cooled and filtered. The filtrate was extracted with 3 N HCl three times, and the collected acid washes were washed with ethyl acetate. The acidic solution was made basic by the careful addition of solid sodium carbonate. This aqueous solution was extracted with ethyl acetate three times, and the organic fractions were combined. The ethyl acetate solution was washed with brine, dried over MgSO4 and concentrated to yield the title product (6.5 g (38%), 35 mmol). 1H NMR (DMSO-d6): δ=11.99 (bs, 2H), 7.31 (d,1H, J=2.1 Hz), 6.84 (d, 1H, J=2.1 Hz), 5.90 (bs, 2H). Calculated mass=188.03, [M+H]+=189.

1. stirringto stir for another 3 hours
2. temperatureThe reaction mixture was then cooled
3. filtrationfiltered
4. extractionThe filtrate was extracted with 3 N HCl three times
5. washthe collected acid washes were washed with ethyl acetate
6. additionThe acidic solution was made basic by the careful addition of solid sodium carbonate
7. extractionThis aqueous solution was extracted with ethyl acetate three times
8. washThe ethyl acetate solution was washed with brine
9. dry with materialdried over MgSO4
10. concentrationconcentrated

ORD record

ord-83dcbb0d9a9441c48c4fd42dafe1d084

Source dataset

uspto-grants-2010_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07696210B2