Background and overview[1]
Symmetric diaryl ketones are an important class of organic synthesis intermediates and are widely used in medicine, pesticides, polymer materials and other fields. For example: benzophenone is a key intermediate in the preparation of the anti-vertigo drugs diphenhydramine and diphenidol, and 4,4’-difluorobenzophenone is a key intermediate in the preparation of the cerebrovascular drug flunarizine. In addition, many natural products and pharmaceutically active molecules contain symmetric diaryl ketone backbone structures. Bis(4-tert-butylphenyl)methanone is a kind of symmetric diaryl ketone, which can be used as a pharmaceutical and chemical synthesis intermediate.
Preparation[1]
Preparation of di(4-tert-butylphenyl)methanone:
Add 4-tert-butylphenylboronic acid (0.249g, 2mmol), 5wt% Pd/CaCO3 (0.0456g, Pd0.01mmol) and CuI (0.0114g, 0.03mmol) to the pressure of 250mL polytetrafluoro lining In the reaction kettle, add DMSO (10mL), install the reaction kettle, slowly introduce 1.85atm of air in the fume hood, then introduce 0.15atm of CO, and then place the reaction kettle in a 50°C oil bath for reaction 12 hours. After the reaction has stopped, cool the reaction kettle to room temperature and slowly release the remaining gas in the kettle in a fume hood. Open the reaction kettle, add 40 mL of ammonia water with a mass concentration of 5%, filter and separate the palladium catalyst, which can be reused after washing and drying. The mother liquor was extracted three times with dichloromethane (30 mL), and the organic phases were combined. The organic phase was dried over anhydrous sodium sulfate, concentrated in vacuo to remove the solvent, and the crude product was purified by column chromatography (volume ratio 20:1 petroleum ether/ethyl acetate). eluent) to obtain bis(4-tert-butylphenyl)methanone as a white solid, melting point: 47~49°C.
Main reference materials
[1]CN201811541806.6 A method for preparing symmetric diaryl ketones by catalytic oxidative carbonylation
