Phthalic Anhydride → 2-(2,4-difluorobenzoyl)benzoic Acid

Participants

Reaction Conditions

Reaction Steps

To a mixture of phthalic anhydride (64.8 g, 438 mmol), tetrachloroethane (600 mL) and 1,3-difluorobenzene (100 g, 877 mmol) was added anhydrous AlCl3 (141 g, 964 mmol) over 20 minutes while maintaining the reaction temperature below 40° C. The temperature was increased to 90° C. for 2 hours, the reaction mixture was cooled and poured into ice/6N HCl. The mixture was extracted with ether (2×1.2 L) and the combined ether extracts were dried over Na2SO4. The solvent was removed in vacuo and the residue was recrystallized from hot ethyl acetate to afford 86.5 g (75%) of 2-(2,4-difluorobenzoyl)benzoic acid, m.p. 129°-131° C.

Provenance & Evidence