Hydrochloric Acid → 2-(4-Fluorobenzoyl)benzoic acid

Participants

Reaction Steps

To a stirred mixture of 25 parts of 1,3-isobenzofurandione and 108.5 parts of fluorobenzene were added portionwise 50 parts of aluminium chloride. Upon completion, the whole was heated slowly to reflux and stirring was continued for 1.50 hours at reflux temperature. The reaction mixture was cooled and poured onto a mixture of crushed ice and 60 parts of concentrated hydrochloric acid. The product was extracted twice with dichloromethane. The combined extracts were washed with a sodium hydroxide solution 10%. The aqueous phase was separated, washed with 2,2'-oxybispropane and acidified with concentrated hydrochloric acid while cooling. The whole was stirred for one hour at room temperature. The precipitated product was filtered off and dissolved in benzene. The solution was distilled azeotropically to dry. The solid residue was stirred in hexane. The product was filtered off and dried in vacuo at about 50° C., yielding 33.5 parts (80.7%) of 2-(4-fluorobenzoyl)benzoic acid; mp. 129.2° C. (intermediate 7).

Provenance & Evidence