反应详情

A solution of 5,0 g (24,5 mmol) 7,8-dihydroxy-1,2,5-oxadiazolo(3,4-f)quinoxaIine and 6,8 ml (49 mmol) triethylamine in 500 ml dimethylformamide was hydrogenated at atm. pressure using 5% Pd-C (0,5 g) as a catalyst. The reaction mixture was filtered and evaporated in vacuo. The residue was stirred with water, and the precipitate was filtered off to give 4,5 g (96%) 5,6-diamino-2,3-dihydroxyquinoxaline, m.p. >300° C. NMR (DMSO-d6) 11.0 (2H, broad m), 6.43 (1H,d), 6.23 (1H,d), 4.5 (4H, broad m).

1. filtrationThe reaction mixture was filtered
2. customevaporated in vacuo
3. filtrationthe precipitate was filtered off