Synthesis
1) In a dry reaction vessel, anhydrous aluminum trichloride (0.1-0.18 moles) and methylene chloride (30-60 ml) were added and stirred until homogeneous. Subsequently, a mixed solution consisting of ferrocene (0.03-0.06 moles), methylene chloride (80-100 ml) and acetyl chloride (0.1-0.16 moles) was added slowly and dropwise. The reaction was first stirred at room temperature for 3-5 hours and then heated to reflux for 3-4 hours. Upon completion of the reaction, 70-100 ml of distilled water was slowly added to hydrolyze the aluminum trichloride, taking care to prevent splashing. After completion of hydrolysis, the reaction mixture was extracted with dichloromethane and the lower organic phase was separated in a separatory funnel. The upper aqueous phase was extracted three times with a small amount of dichloromethane and the organic phases were combined. The organic phase was dried with anhydrous magnesium sulfate, filtered to remove the desiccant and concentrated to give the crude product. The crude product was purified by aqueous recrystallization to give red needle-like crystals of 1,1'-diacetylferrocene in about 80% yield.
References
[1] Journal of the Chemical Society, Perkin Transactions 1, 2000, # 10, p. 1551 - 1557
[2] Patent: CN108530493, 2018, A. Location in patent: Paragraph 0032; 0038; 0044; 0049
[3] Patent: CN107226829, 2017, A. Location in patent: Paragraph 0022; 0026; 0030
[4] Journal of Organic Chemistry, 2015, vol. 80, # 19, p. 9563 - 9569
[5] Patent: CN104292274, 2017, B. Location in patent: Paragraph 0057
