Reacción #81999

Ecuación de reacción

diethyl oxalate

4,5-difluoro-1,2-diaminobenzene

→

title compound

6,7-Difluoro-1,4-dihydro-2,3-quinoxalinedione

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturawas heated
2. 2
   Temperaturato reflux under N2 for 2 h
3. 3
   Filtraciónthe solid collected by vacuum filtration
4. 4
   Lavadorinsed with hexanes and air
5. 5
   Otrodried
6. 6
   OtroThis gray brown solid was recrystallized from 20 ml of EtOH
7. 7
   Filtraciónthe brown-white crystals collected by vacuum filtration
8. 8
   Otrothe crystals further dried under vacuum (0.5 torr, 25° C.)
9. 9
   Otroto yield 45.3 mg (30.0%) mp >360° C. (lit. >310° C.)

Procedimiento

The title compound (Sarges, R. et al., J. Med. Chem. 33: 2240 (1990)) was prepared using an adaptation of the method of Cheeseman. (Cheeseman, G. W. H. J. Chem. Soc. 1171 (1962)). A mixture of diethyl oxalate (1.11 g, 7.63 mmol and 4,5-difluoro-1,2-diaminobenzene (110 mg, 0.763 mmol) was heated to reflux under N2 for 2 h. The reaction was allowed to cool to room temperature and the solid collected by vacuum filtration and rinsed with hexanes and air dried. This gray brown solid was recrystallized from 20 ml of EtOH and the brown-white crystals collected by vacuum filtration and the crystals further dried under vacuum (0.5 torr, 25° C.) to yield 45.3 mg (30.0%) mp >360° C. (lit. >310° C.). 1H NMR (d6 -acetone) δ 7.19 (t, 2H, ArH, JH-F =9.3), 10.9 (br s, 2H, NH).

Fuente