Reacción #82072

Ecuación de reacción

ethanol

3,4,5-trifluoro-1,2-phenylenediamine

oxalic acid

→

pure title compound

Rendimiento 36.0%

5,6,7-Trifluoro-1,4-dihydro-2,3-quinoxalinedione

Rendimiento 36.0%

Disolventes

HCl

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturato reflux
2. 2
   FiltraciónThe mixture is filtered
3. 3
   Otroto yield 139 mg (37%) of crude title compound
4. 4
   OtroAn analytical sample is prepared
5. 5
   TemperaturaUpon cooling
6. 6
   Otrobrown rod-like crystals were formed which
7. 7
   Filtraciónare filtered
8. 8
   Otrodried in vacuo

Procedimiento

To a brown solution of 3,4,5-trifluoro-1,2-phenylenediamine (285 mg, 1.75 mmol) in aqueous 2N HCl (10 mL) is added oxalic acid (221 mg, 1.75 mmol). The brown mixture is brought to reflux and stirred under N2 overnight. The mixture is filtered to yield 139 mg (37%) of crude title compound. An analytical sample is prepared by dissolving 42 mg of this brown powder in 2.5 mL boiling ethanol. Upon cooling, brown rod-like crystals were formed which are filtered and dried in vacuo to yield 15 mg (36%) of pure title compound: 1H NMR (DMSO-d6), 6.91 (m, 1H), 12.02 (s, 1H), 12.19 (s, 1H); analysis calculated for C8H3F3N2O2 : C, 44.46; H, 1.40; N, 12.96. Found: C, 44.42; H, 1.16; N, 12.76.

Fuente