Hydrochloric Acid → 9-Hydroxy-9H-indeno[1,2-b]pyrazine-2,3(1H,4H)-dione

Participants

Reaction Steps

To a stirred suspension of 9H-indeno[1,2-b]pyrazine-2,3,9(1H,4H)-trione.-1H2O (5.0 g, 21.5 mmol) in 200 ml of ethanol and 30 ml of water was added sodium borohydride (1.76 g, 46.5 mmol) in four portions over 2 hours, then 200 ml of water was added and the mixture was stirred for 18 hours at room temperature. The reaction mixture was acidified with hydrochloric acid (70 ml, 1N) to pH 1.5 and the precipitate was filtered off, washed with water and dried to give 4.59 g (91%) of the title compound. M.p.>300° C. 1H-NMR (DMSO-d6, δ): 5.1 (d, 1H), 5.72 (d, 1H), 7.15 (t, 1H), 7.28 (t, 1H), 7.41 (d, 1H), 7.48 (d, 1H), 12.0 (s, 1H), 12.25 (s, 1H).

Provenance & Evidence