4-fluoro-3-methylphenyl 4-fluorophenyl ketone synthesis

Yield:59396-50-8 61.5%

Reaction Conditions:

with potassium hydroxide;HF;boron trifluoride in water;

Steps:

1 EXAMPLE 1

EXAMPLE 1 Into a 250 ml stainless steel reactor equipped with a magnetic stirrer system, 100 ml of anhydrous HF, 42.7 g (0.2 mole) of p-fluorotrichloromethylbenzene, and 22 g (0.2 mole) of orthofluorotoluene were introduced at about 0° C. The reactor was closed, after which gaseous boron trifluoride was introduced until a constant pressure of 6 bars was achieved. The reaction was then allowed to proceed with stirring at ambient temperature for 3 hours. After reaction, the reactor was decompressed to atmospheric pressure, and the reaction mixture poured over 200 g of crushed ice. Following warming up to ambient temperature, the heterogeneous mixture was stirred for one to two hours, then extracted three times with 200 ml of methylene chloride. The organic phases were washed three times with 200 ml of water, once with 200 ml of an aqueous 3% potassium hydroxide solution, and twice with 200 ml of water. The organic phase was dried over magnesium sulfate and the solvent eliminated by distillation under reduced pressure. 35.3 g (yield: 61.5%) of raw 4,4'-difluoro-3-methylbenzophenone was recovered.

References:

US4453012,1984,A