反应详情

To a suspension of 61 (1.617 g, 8.79 mmol) in MeOH (75 mL) was added 20% aq. (NH4)2S (15 mL, 44 mmol) dropwise at room temperature with stirring. The resulting dark-red solution was stirred at room temperature for 0.5 h, then refluxed for 0.5 h, then cooled to room temperature. The resulting mixture was filtered. The filtrate was concentrated to about 30 mL and cooled in ice-water. The precipitate was filtered, washed with cooled EtOH (2×5 mL), and dried to give 1.092 g (80%) of 62 as a deep red powder, mp 260°-2° C.(dec) (Lit., 260° C., Chemical Abstracts 65:3826 (1966)). 1H NMR (DMSO-d6): 5.311 (s, 2H), 6.984 (s, 2H), 7.342 (d, 1H, J=2.2), 8.171 (d, 1H, J=2.2).

1. stirringThe resulting dark-red solution was stirred at room temperature for 0.5 h
2. temperaturerefluxed for 0.5 h
3. filtrationThe resulting mixture was filtered
4. concentrationThe filtrate was concentrated to about 30 mL
5. temperaturecooled in ice-water
6. filtrationThe precipitate was filtered
7. washwashed with cooled EtOH (2×5 mL)
8. customdried