反应详情

1.81 g (5.6 mmol) of hafnium tetrachloride are added to a suspension, cooled to -78° C., of 2.00 g (5.64 mmol) of the dilithium salt (Example 4) in 150 ml of toluene. The orange suspension in allowed to warm to room temperature, and is stirred for a further 2 days in order to complete the reaction. Insoluble constituents are then filtered off via a frit, and the orange-red filtrate is evaporated to dryness on an oil pump 30 ml of pentane are added to the orange-red residue, and the mixture is stirred vigorously overnight. Removal of the solvent in vacuo gives the hafnocene dichloride as beige powder in a crude product yield of 700 mg (24%). The 1H-NMR spectrum of the crude product shows only one diastereomer.

1. customthe reaction
2. filtrationInsoluble constituents are then filtered off via a frit
3. customthe orange-red filtrate is evaporated to dryness on an oil
4. additionare added to the orange-red residue
5. stirringthe mixture is stirred vigorously overnight
6. customRemoval of the solvent in vacuo