反应详情

7.5 g of 2-carboxy-5,5'-dimethoxybiphenyl was dissolved in 75 mL of methanesulfonic acid to obtain a dark brown solution. The solution was stirred at room temperature for one hour, heated at 40°-50° C. for 5 hours and then cooled to room temperature. The reaction mixture was then poured onto crushed ice to form a yellow colored precipitate which was collected by filtration. The precipitate was washed with large amounts of water and then air dried to yield 6.7 g of crude 3,6-dimethoxy-9-fluorenone. Recrystallization from ethanol followed by column chromatography on silica gel using methylene chloride as the eluent yielded pure 3,6-dimethoxy-9-fluorenone. The structure was confirmed by NMR and mass spectroscopy.

1. customto obtain a dark brown solution
2. temperatureheated at 40°-50° C. for 5 hours
3. temperaturecooled to room temperature
4. additionThe reaction mixture was then poured
5. customonto crushed ice
6. customto form a yellow colored precipitate which
7. filtrationwas collected by filtration
8. washThe precipitate was washed with large amounts of water
9. customair dried