Nitric Acid → 7-Fluoro-6-nitro-2H-1,4-benzoxazin-3(4H)-one

HRID 518972Notes

Reaction equation

[F:1][C:2]1[CH:12]=[CH:11][C:5]2[NH:6][C:7](=[O:10])[CH2:8][O:9][C:4]=2[CH:3]=1.[N+:13]([O-])([OH:15])=[O:14]>OS(O)(=O)=O>[F:1][C:2]1[C:12]([N+:13]([O-:15])=[O:14])=[CH:11][C:5]2[NH:6][C:7](=[O:10])[CH2:8][O:9][C:4]=2[CH:3]=1

Participants

Conditions

Temperature: -10 °C

Procedure

To a solution of 7-fluoro-4H-benzo[1,4]oxazin-3-one (3.00 g, 17.95 mmol) in concentrated H2SO4 (12 mL) at −10° C. was added a mixture of fuming nitric acid (1.131 g, 17.95 mmol, 0.75 mL) and concentrated H2SO4 (0.75 mL) dropwise, keeping the internal temperature below 0° C. After addition, the reaction mixture was stirred at −10° C. for 10 min. The reaction mixture was poured onto crushed ice (200 g) with care. The precipitate was collected by filtration, washed with water (50 mL) and dried in vacuo to give 7-fluoro-6-nitro-4H-benzo[1,4]oxazin-3-one as a light yellow solid (3.5 g, 92%). 1H NMR (DMSO-d6, 400 MHz): δ 11.02 (s, 1H), 7.61 (d, J=7.6 Hz, 1H), 7.23 (d, J=12.0 Hz, 1H), 4.77 (s, 2H).

Workup

customthe internal temperature below 0° C
additionAfter addition
additionThe reaction mixture was poured
filtrationThe precipitate was collected by filtration
washwashed with water (50 mL)
customdried in vacuo

Sources & evidence

ORD record: ord-3997ac9bef4f43229d070b32b70ed8aa
Source dataset: uspto-grants-2015_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09115151B2

Reaction notes

Loading…