Water → 9H-Indeno[1,2-b]pyrazine-2,3,9(1H, 4H)-trione 9-ethylene dithioacetal

Participants

Reaction Steps

A suspension of 9H-indeno[1,2-b]pyrazine-2,3,9(1H, 4H)-trione. 0.9 H2O (2.0 g, 8.68 mmol) in toluene (50 ml), 1,2-ethanedithiol (2.19 ml, 26.04 mmol) and boron trifluoride etherate (1.07 ml, 8.68 mmol) was refluxed for 20 hours. The reaction mixture was cooled to room temperature, and the precipitate was filtered off and washed with toluene, ethanol-water (2:1) and ethanol. The crude material (2.40 g) was recrystallized from DMF-water to give 2.09 g (83%) of the title, compound. M.p.>300° C. 1H-NMR (DMSO-d6, δ): 3.68 (m, 2H), 3.91 (m, 2H), 7.2 (t, 1H), 7.3 (t, 1H), 7.51 (d, 1H), 7.59 (d, 1H), 12.05 (s, 1H), 12.38 (s, 1H).

Provenance & Evidence