Oxalic acid dihydrate → HCID 178527601, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 0,5 g (2,1 mmol) 1,2-diaminonaphthalene-5-sulphonic acid and 0,75 g (5,8 mmol) oxalic acid dihydrate in 25 ml 4N hydrochloric acid was refluxed for 4 h. After cooling to 25° C., the precipitate was filtered off and washed with 5 ml 4N hydrochloric acid and 5 ml ice-cooled water. The crude product was dissolved in 15 ml 4N sodium hydroxide, and then reprecipitated with 4N hydrochlorid acid to give 0,35 g (57%) of 2,3-dihydroxy-benzo(f)quinoxaline-7-sulphonic acid, m.p. > 300° C. IR (KBr): 3450 (m), 1690 (s), 1190 (s), 1055 (s), 1020 (s) cm-1.1H NMR (DMSO-d6): 12,2 (2H,s), 8,7 (1H,d), 8,6 (1H,d), 8,0 (1H,d), 7,5 (1H,t), 7,4 (1H,d).

Provenance & Evidence