2175-90-8

78.0 g (0.24 mol) of sodium methylate solution were initially introduced into a 500 ml four-necked flask at 50° C. and 45.6 g (0.25 mol) of benzophenone were then added. After complete dissolution, 20 g (0.30 mol) of freshly distilled cyclopentadiene were added dropwise in the course of 30 min at 45-50° C. After the end of the addition, stirring was effected for a further 2 h at room temperature, a dark red suspension forming. This was filtered over a G3 frit and the solid was washed four times with 25 ml of ethanol each time. After drying in a vacuum from an oil pump, 47.1 g (0.20 mol; 82% yield) of red 6,6-diphenylfulvene were obtained.