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

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 1 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 (87.7%) of 2-(4-fluorobenzoyl)benzoic acid; mp. 129.2° C. (intermediate 90).

1. temperatureUpon completion, the whole was heated slowly
2. temperatureto reflux
3. temperatureat reflux temperature
4. temperatureThe reaction mixture was cooled
5. extractionThe product was extracted twice with dichloromethane
6. washThe combined extracts were washed with a sodium hydroxide solution 10%
7. customThe aqueous phase was separated
8. washwashed with 2,2'-oxybispropane
9. temperaturewhile cooling
10. stirringThe whole was stirred for 1 hour at room temperature
11. filtrationThe precipitated product was filtered off
12. dissolutiondissolved in benzene
13. distillationThe solution was distilled azeotropically
14. customto dry
15. stirringThe solid residue was stirred in hexane
16. filtrationThe product was filtered off
17. customdried in vacuo at about 50° C.

ORD 기록

ord-e03c3cfe18cc42acbd0e13d780b9d8d7

출처 데이터셋

uspto-grants-1991_10

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US05057525