反应详情

The title compound was prepared using an adaptation of the method of Cheeseman (Cheeseman, G. W. H., J. Chem. Soc. 1171 (1962)). A mixture of diethyl oxalate (3.31 mL, 24.4 mmol) and 1,2-diamino-3-bromo-5-fluorobenzene (500 mg, 2.44 mmol) was heated to reflux under N2 for 5 h. The reaction mixture was dark brown. The reaction was allowed to cool to room temperature and the solid collected by vacuum filtration and rinsed with EtOH (30 mL). The brown solid was air dried for 1 hr to give 250 mg (39.6% crude yield). A portion of this solid was removed and dissolved in 1N NaOH (10 mL) and a few insoluble particles were removed by gravity filtration. The solution was treated with decolorizing carbon and the mixture was filtered through a pad of celite and the resulting solution acidified with 1N HCl. White crystals formed that were isolated by vacuum filtration and washed with water (20 mL). The crystals were dried in a drying pistol (0.05 torr, 78° C.) to yield 54.1 mg, mp 308°-310° C. (dec). 1H NMR (d6 -DMSO) δ6.2 (dd, 1H, JH6-8 =2.7, JH-F =9.3, ArH), 7.35 (dd, 1H, JH6-8 =2.4, JHF =8.4 Hz), 11.1 (br s, 1H, NH), 12.1 (brs, 1H, NH). EIHRMS calc. for C8H4BrFN2O2 : 257.9440, found 257.9455.

1. temperaturewas heated
2. temperatureto reflux under N2 for 5 h
3. filtrationthe solid collected by vacuum filtration
4. washrinsed with EtOH (30 mL)
5. customdried for 1 hr
6. customto give 250 mg (39.6% crude yield)
7. customA portion of this solid was removed
8. dissolutiondissolved in 1N NaOH (10 mL)
9. customa few insoluble particles were removed by gravity filtration
10. additionThe solution was treated with decolorizing carbon
11. filtrationthe mixture was filtered through a pad of celite
12. customWhite crystals formed
13. customthat were isolated by vacuum filtration
14. washwashed with water (20 mL)
15. customThe crystals were dried in a drying pistol (0.05 torr, 78° C.)
16. customto yield 54.1 mg, mp 308°-310° C. (dec)