Nitric Acid → 2,6-Dibromo-4-nitro-1-oxo-1lambda~5~-pyridine

Temperature

79 °C

2,6-dibromo pyridine 1-oxide (10 g, 39.5 mmol) was added to 65 mL of concentrated sulfuric acid at room temperature without cooling. Concentrated sulfuric acid (15 ml) and nitric acid (13.3 ml) were mixed and placed in a pressure equalising dropping funnel. The reaction mixture was heated to 79° C. then the nitrating mixture was added in portions over 25 minutes. When the addition was complete the mixture was stirred at 83-85° C. for 3.5 hours. The mixture was cooled to room temperature and slowly poured onto ˜250 g crushed ice. A very pale yellow solid formed which was filtered off and washed with water (100 ml), dried in vacuum oven at 50° C. overnight to give 10.9 g of the title compound.

1. temperaturewithout cooling
2. additionthe nitrating mixture was added in portions over 25 minutes
3. additionWhen the addition
4. temperatureThe mixture was cooled to room temperature
5. additionslowly poured onto ˜250 g
6. customcrushed ice
7. customA very pale yellow solid formed which
8. filtrationwas filtered off
9. washwashed with water (100 ml)
10. customdried in vacuum oven at 50° C. overnight

ORD record

ord-2ab1a36c1ca1458398859691087e2363

Source dataset

uspto-grants-2010_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07691877B2