Potassium Nitrate → 6-Chloro-5-nitro-7-trifluoromethyl-1,4-dihydro-2,3-quinoxalinedione

HRID 53785Notes

Reaction equation

[Cl:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][C:11]=1[C:12]([F:15])([F:14])[F:13])[NH:8][C:7](=[O:16])[C:6](=[O:17])[NH:5]2.[N+:18]([O-])([O-:20])=[O:19].[K+]>OS(O)(=O)=O.[OH-].[K+]>[Cl:1][C:2]1[C:3]([N+:18]([O-:20])=[O:19])=[C:4]2[C:9](=[CH:10][C:11]=1[C:12]([F:14])([F:15])[F:13])[NH:8][C:7](=[O:16])[C:6](=[O:17])[NH:5]2

Participants

Conditions

Temperature: 0 °C

Procedure

To a solution of 6-chloro-7-trifluoromethyl-1,4-dihydro-2,3-quinoxalinedione (31 mg, 0.12 mmol) in concentrated H2SO4 (0.3 mL) at 0° C. was added KNO3 (14 mg, 0.141 mmol, Baker). The mixture was stirred at 0° C. for 0.5 h and then at room temperature for 20 h and it was poured into ice water (2 g). The precipitate was collected by filtration, giving 31 mg of crude title compound. The sample was dissolved in 1N KOH (1 mL) and filtered. The filtrate was acidified to pH=2 with 4N HCl to give a yellow precipitate which was collected by filtration and then dried in air at 50° C. for 4 h to give the title compound (29 mg, 80%) as a yellow powder. Crystallization from DMSO/H2O gave pure compound (18 mg) as yellow microcrystals. mp: 342°-5° C., IR (KBr, cm-1): 3394, 3301, 3248, 3209, 1761, 1701, 1628, 1542. 1H NMR (DMSO-d6): δ 7.618 (s, 1H), 12.351 (s, 1H), 12.552 (s, 1H). HRMS: calcd for C9H3ClF3N3O4 (M+) m/z: 308.9763, found: 308.9759.

Workup

waitat room temperature for 20 h
filtrationThe precipitate was collected by filtration
customgiving 31 mg of crude title compound
filtrationfiltered
customto give a yellow precipitate which
filtrationwas collected by filtration
customdried in air at 50° C. for 4 h

Sources & evidence

ORD record: ord-36da02b22ed345d3bdeb04fa171e114b
Source dataset: uspto-grants-1997_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05620979

Reaction notes

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