Nitric Acid → 2,6-Dichloro-3-nitropyridin-4-amine

To a solution of 2,6-dichloro-4-aminopyridine (5.0 g, 30.6 mmol) in conc. H2SO4 (25 mL) at 0° C. in an ice-acetone bath was added 90% HNO3 (10 mL) dropwise. The reaction mixture was warmed to ambient temperature and stirred for 1 h then poured onto ice (100 g). The solid precipitate was isolated by filtration, washed with cold H2O and dried under high vacuum. The resulting solid was dissolved in conc. H2SO4(50 mL) and heated at 100° C. for 20 min. The reaction mixture was poured onto ice (150 g) and neutralized with conc. NH4OH while maintaining the temperature below 20° C. The precipitate was isolated by filtration, washed with cold H2O, and dried to yield the title compound. MS: m/z=208 (M+1).

1. additionthen poured onto ice (100 g)
2. customThe solid precipitate was isolated by filtration
3. washwashed with cold H2O
4. customdried under high vacuum
5. dissolutionThe resulting solid was dissolved in conc. H2SO4(50 mL)
6. temperatureheated at 100° C. for 20 min
7. additionThe reaction mixture was poured onto ice (150 g)
8. temperaturewhile maintaining the temperature below 20° C
9. customThe precipitate was isolated by filtration
10. washwashed with cold H2O
11. customdried

ORD record

ord-d05267f865aa4132aa8eadd7a476053f

Source dataset

uspto-grants-2012_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08133891B2