反应详情

The Grignard reagent prepared from 0.72 g (30 mmol) of magnesium turnings and 5.1 ml (30 mmol) of 2-bromobiphenyl in 15 ml of diethyl ether is added dropwise over a period of 2 hours, while stirring (in an ultrasonic bath), to a boiling suspension of 10.0 g (29.6 mmol) of 2,7-dibromo-9-fluorenone in 100 ml of dry diethyl ether. After the addition is complete, the mixture is boiled for a further 3 hours. After cooling overnight, the precipitated solid is filtered off with suction and washed with cold ether. The magnesium complex filtered off is hydrolyzed in a solution of 15 g of ammonium chloride in 250 ml of ice water. After 1 hour, the 9-(2-biphenylyl)-2,7-dibromo-9-fluorenol formed is filtered off with suction, washed with water and sucked dry. For the ring-closure reaction, the dried fluorenol is boiled in 100 ml of glacial acetic acid for 6 hours, after addition of 3 drops of concentrated HCl. The mixture is allowed to crystallize overnight, the product formed is filtered off with suction and is washed with glacial acetic acid and water.

1. additionis added dropwise over a period of 2 hours
2. additionAfter the addition
3. temperatureAfter cooling overnight
4. filtrationthe precipitated solid is filtered off with suction
5. washwashed with cold ether
6. filtrationThe magnesium complex filtered off
7. waitAfter 1 hour