反应详情

Praseodymium (III) trifluoromethanesulfonate (3.53 g as a wet solid) and para-toluic acid (1.36 g) were refluxed together in 125 mL toluene with azeotropic removal of the lower water layer (Dean-Stark apparatus). After 24 hours, the mixture was cooled and extracted with 3×25 mL water, then by 2×25 mL saturated sodium bicarbonate solution. The organic layer was dried using anhydrous sodium sulfate, filtered, then concentrated down in vacuo to give crude 4,4′-dimethylbenzophenone (0.65 g, 31% yield) as a cream-colored crystalline solid. This was then recrystallized from methanol to give white needles of pure 4,4′ dimethylbenzophenone (0.19 g,9% yield) (M.P. 90.5-91.5° C.).

1. temperaturethe mixture was cooled
2. extractionextracted with 3×25 mL water
3. customThe organic layer was dried
4. filtrationfiltered
5. concentrationconcentrated down in vacuo
6. customto give crude 4,4′-dimethylbenzophenone (0.65 g, 31% yield) as a cream-colored crystalline solid
7. customThis was then recrystallized from methanol