To a 300 ml three-neck flask equipped with a magnetic stirrer chip and a three-way cock, 4.5 g (33.0 mmol) of 1-methyl-3-tert-butyl-cyclopentadiene and 150 ml of THF were charged under a nitrogen atmosphere. In the dry ice/methanol bath, 22.5 ml (34.7 mmol) of 1.54M n-butyllithium hexane solution was gradually added dropwise and then stirred at room temperature for 20 hours. To the obtained reaction solution, 4.3 ml (39.6 mmol) of 1,3-di-methyl-2-imidazolidinone was added, subsequently 8.3 g (39.6 mmol) of 4,4′-di-methylbenzophenone were changed, and the resultant solution was stirred for 120 hours under reflux. The reaction solution was poured into 100 ml of 2N hydrochloric acid. The organic layer was separated, and the aqueous layer was extracted twice with 50 ml of hexane. The separated organic layers were combined, washed with a saturated aqueous solution of sodium hydrogencarbonate, water and saturated aqueous solution of sodium chloride, and dried over magnesium sulfate and the solvent was distilled off. Thereafter, the resulting product was purified by column chromatography to obtain 6.2 g of an orange solid. The yield was 56%. Identification was done by 1H-NMR spectrum. The measurement results are shown as follows.
