2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 1,2,3,6-Tetrahydro-1,3-dioxo-4-phenylpyrrolo[3,4-c]carbazole

Beteiligte Stoffe

Reaktionsschritte

1.2 g (3.8 mmole) 1,2,3,3a,4,5,6,10c-octahydro-1,3-dioxo-4-phenylpyrrolo[3,4-c]carbazole and 2.2 g (9.7 mmole) DDQ are heated under reflux for 20 hours in 30 ml toluene. The solvent is distilled off in a vacuum and the residue chromatographed on silica gel with toluene/ethyl acetate 3:1. The fraction with the Rf of 0.3 is isolated, stirred up with acetone/diisopropyl ether, and the crystals formed are filtered off. One obtains 1,2,3,6-tetrahydro-1,3-dioxo-4-phenyl-pyrrolo[3,4-c]carbazole in the form of yellow crystals of the mp 262°-263° C.

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