Diphenyl Ether → 4'-Phenoxyacetophenone

Participants

Reaction Conditions

Reaction Steps

To a frozen solution of 1.70 g. (0.010 mole) diphenyl ether in 1.30 g. (0.012 mole; a 20 mole % excess) acetic anhydride, was added 3.0 ml anhydrous hydrogen fluoride (50% by weight of reactants). A magnetic stirrer was added and the reaction mixture was stirred magnetically and degassed several times while warming to 24° C. in air, and stirred for 18 hours at 24° C. The resultant red solution was poured into a plastic beaker and allowed to evaporate in an air stream/24° C., leaving a crystalline residue. This was crushed in ca 30 ml ice water, collected by filtration, partly air dried and further dried at 40° C. under a vacuum for about 2 hours, yielding 2.0 g. (94.2%) of nearly colorless crystals with a yellow tinge. Analysis showed only 0.73% unreacted diphenyl ether or 99.25% yield of p-phenoxyacetophenone by gas-liquid chromatography GLC. Thin layer chromatography (TLC) showed a very weak fast moving impurity spot corresponding to diphenyl ether while no trace of a slower moving spot which would correspond to a diacylation product was observed. The product had a melting point of 47°-50° C.

Provenance & Evidence