1,1′-Diacetylferrocene

dark orange to dark red powder

1) Adding anhydrous 0.1-0.18 mol of aluminum trichloride and 30-60 mL of dichloromethane, stir well, then slowly add a mixture of ferrocene 0.03-0.06 mol, dichloromethane 80-100 mL and acetyl chloride 0.1-0.16 mol, and add dropwise. The reaction is first carried out at room temperature for 3-5 h, then refluxed for 3-4 h, the reaction is stopped, and aluminum trichloride is slowly hydrolyzed with 70-100 mL of distilled water to prevent splashing. After the hydrolysis is completed, it is extracted with dichloromethane, and the lower layer product is separated in a separating funnel. The upper aqueous solution is extracted three times with a small amount of CH 2 Cl 2 and combined into the product. Dry over anhydrous MgSO4, filter MgSO4, dry The crude product was recrystallized from water to give a red needle crystal, 1, 1'-diacetylferrocene (a) yield: 80percent.To a 250 mL round bottom reaction flask was added 5.36 g of aluminum trichloride and 15 mL of dichloroethane, Under ice-cooling, 2.8 mL (i.e., 38 mmol) of acetyl chloride was added dropwise, Continue to stir until the basic solution of aluminum trichloride.In another 250 mL round bottom reaction flask, 3.00 g (i.e., 16 mmol) of ferrocene was added, And completely dissolved with 20 mL of dichloroethane.Ice water cooling, The ferrocene dichloroethane solution was slowly added dropwise to a solution of aluminum trichloride and acetyl chloride using a constant pressure dropping funnel, Continue stirring in the ice bath for 3 hours.After returning to room temperature, The reaction was complete at 40 ° C until the reaction was complete (using thin layer chromatography).The reaction is poured into ice water, Separate the organic phase, followed by water, 5percent sodium carbonate solution and water, Dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure, To give a dark brown oil, Recrystallization to obtain orange-red needle-like crystals of 1, 1'-diacetyl ferrocene, The yield was 72percent.In a three-neck flask, add fine aluminum trichloride 8.9738g/67.3mmol and dichloromethane 20ml, A solution of acetyl chloride (6.7 ml/94.2 mmol) in dichloromethane was added with stirring under ice-cooling and stirred until the aluminum trichloride was substantially dissolved. A solution of ferrocene 5g/26.9 mmol in dichloromethane (20 ml) was then added, and the mixture was stirred overnight at 10° C. for 1 h and then stirred at room temperature until evolution of hydrogen chloride (about 3 h). The system was transferred to ice until all ice had melted. The organic phase was separated off with a funnel. The aqueous phase was extracted with chloroform. The organic phases were combined, washed successively with water and saturated sodium bicarbonate solution, and dried over anhydrous sodium sulfate. The solvent was distilled off to give a crude orange-yellow solid diacetylferrocene. The crude product was purified by silica column chromatography with CHCl3/CH3OH=50/1 as eluent in a yield of 68.8percent.