9-Oxofluorene-4-carboxylic acid → 4-(1H-benzimidazol-2-yl)-fluoren-9-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

In a 50-ml three-necked flask under an argon atmosphere, heat, at 80° C. for 2 hours, a solution of 3 g of the (2-amino-phenyl)amide of 9-oxo-9H-fluorene-4-carboxylic acid obtained in the preceding stage, in 150 ml of acetic acid. After cooling, the precipitate that formed is drained. After purification by silica gel flash chromatography, eluting with mixtures of dichloromethane and ethyl acetate (90-10 then 80-20 and finally 70-30 by volume), we obtain 1.73 g of 4-(1H-benzimidazol-2-yl)-fluoren-9-one in the form of a yellow powder, which is used as it is in the next stage, with the following characteristics:

Herkunft & Nachweise