[Cl-].[Cl-].[Cl-].[Cl-].[Cl-].[Ta+5].C([Mg]Br)(C)C.C(C1([Li])C=CC=C1)C.C(C1CC=CC=1)C.C([Li])CCC.[CH2:32]([C:34]1([Ta:39]([C:42]2([CH2:47][CH3:48])[CH:46]=[CH:45][CH:44]=[CH:43]2)(Cl)Cl)[CH:38]=[CH:37][CH:36]=[CH:35]1)[CH3:33].[H-].COCCO[Al+]OCCOC.[Na+].[H-]>CCOCC.C1COCC1.O.C1(C)C=CC=CC=1>[CH2:47]([C:42]1([TaH3:39][C:34]2([CH2:32][CH3:33])[CH:38]=[CH:37][CH:36]=[CH:35]2)[CH:46]=[CH:45][CH:44]=[CH:43]1)[CH3:48]75.0 g (209 mmol) of tantalum pentachloride was suspended in 1,200 ml of ether, and 335 ml (228 mmol) of isopropyl magnesium bromide (0.68M THF solution) was added thereto. A solution of 41.9 g (419 mmol) of ethylcylopentadienyl lithium prepared from ethylcylopentadiene and butyl lithium in THF (240 ml) was added, followed by refluxing for 1 hour. The solvent was distilled away, and the residue was dried at 80° C. in vacuo for 8 hours to obtain a dark brown solid containing bis(ethylcyclopentadienyl)dichlorotantalum (Ta(EtCp)2Cl2). 1,060 ml of toluene was added to this dark brown solid, and the resulting mixture was ice-cooled. 187 ml (623 mmol) of a toluene solution (65 wt %) of sodium bis(2-methoxyethoxy)aluminum hydride was added dropwise to the mixture, and temperature was returned to room temperature, followed by stirring for 17 hours. 107 ml of water was added to the mixture, followed by stirring until foaming does not occur. Insoluble contents were filtered out, and the solvent was distilled away from the filtrate. 590 ml of hexane was added to the residue, the insoluble contents were filtered out. When the filtrate was cooled to −70° C., a white solid was formed. The supernatant was removed, and the solid was washed with 24 ml of cold pentane two times to obtain a solid. The solid obtained was distilled in vacuo at 2.5 Pa/100° C. to obtain 7.79 g (yield: 10.1%) of a colorless liquid. When this liquid was cooled to room temperature, white crystals were formed.
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