反应详情

A suspension of 9H-indeno[1,2-b]pyrazine-3,9(4H)-dione (1.0 g, 5.05 mmol) in ethylene glycol (10 ml), toluene (20 ml) and p-toluenesulfonic acid (20 mg) was refluxed with water separation for 18 hours. The reaction mixture was cooled to room temperature, ethanol (5 ml) was added and the precipitate was filtered off and washed with ethanol and dried to give 1.014 g (83%) of the title compound. M.p. 296°-298° C. 1H-NMR (DMSO-d6, δ): 4.3-4.42 (m, 4H), 7.43-7.6 (m, 3H), 7.75 (d, 1H), 7.88 (s, 1H), 12.7 (s, 1H).

1. filtrationthe precipitate was filtered off
2. washwashed with ethanol
3. customdried