Carbazole → 1,6-Dihydrocyclopenta[c]carbazol-3(2H)-one

Participants

Reaction Conditions

Reaction Steps

Compound 45 (5.0 g) was divided into five portions (1.0 g each). P(OEt)3 (per 7 mL) was added to each portion. The resulting product was subjected to argon blow in a flask, heated to 90° C., kept at this temperature for 3 days, then cooled. The carbazole precipitate was diluted with ether. The precipitate was filtered and washed with ether. If the initial biphenyl was present in the filtrate (TLC monitoring, eluent: hexane-ethyl acetate, 1:1), this filtrate was evaporated, then P(OEt)3 was added (1 mL to each flask), and subjected to cyclization for 1 day. The procedure was repeated until the precipitation ceased and TLC showed the absence of the initial biphenyl. Carbazol 46 (2.7 g) was obtained.

Provenance & Evidence