Boron trifluoride etherate → 9H-Indeno[1,2-b]pyrazine-3,9(4H)-dione 9-ethylene dithioacetal

Participants

Reaction Steps

A suspension of 9H-indeno[1,2-b]pyrazine-3,9(4H)-dione (0.50 g, 2.52 mmol) in benzene (10 ml), 1,2-ethanedithiol (0.63 ml, 7.56 mmol) and boron trifluoride etherate (0.31 ml, 2.52 mmol) was refluxed for 23 hours. The reaction mixture was cooled to room temperature, and the precipitate was filtered off and washed with benzene and water and dried. The crude material (0.64 g) was recrystallized twice from ethanol to give 0.44 g (64%) of the title compound. M.p. 284°-290° C. 1H-NMR (DMSO-d6, δ): 3.75-3.94 (m, 4H), 7.46-7.57 (m, 2H), 7.8 (m, 2H), 7.95 (s, 1H), 12.6 (s, 1H).

Provenance & Evidence