Hydrochloric Acid → 4-(4-Fluorobenzoyl)pyridine

To a stirred and cooled (ice-bath) solution of 141.5 parts of 4-pyridinecarbonyl chloride hydrochloride in 400 parts of fluorobenzene were added portionwise 399 parts of aluminum chloride. Upon completion, the whole was slowly heated to reflux and stirring at reflux was continued for 6 hours. The reaction mixture is cooled, poured onto crushed ice and acidified with 240 parts of a hydrochloric acid solution 10N. The layers were separated. The acid aqueous phase was washed twice with 180 parts of methylbenzene and strongly alkalized with a sodium hydroxide solution 60%. The product was extracted three times with dichloromethane. The combined extracts were dried, filtered and evaporated. The residue was dissolved in 900 parts of methylbenzene and the solution was treated with activated charcoal. The latter was filtered off and the filtrate was evaporated. The residue was crystallized from 2,2'-oxybispropane, yielding 152 parts (75.5%) of (4-fluorophenyl)(4-pyridinyl)methanone; mp. 85.5° C. (intermediate 25).

1. temperatureUpon completion, the whole was slowly heated
2. temperatureto reflux
3. stirringstirring
4. temperatureat reflux
5. temperatureThe reaction mixture is cooled
6. additionpoured
7. customonto crushed ice
8. customThe layers were separated
9. washThe acid aqueous phase was washed twice with 180 parts of methylbenzene
10. extractionThe product was extracted three times with dichloromethane
11. customThe combined extracts were dried
12. filtrationfiltered
13. customevaporated
14. dissolutionThe residue was dissolved in 900 parts of methylbenzene
15. additionthe solution was treated with activated charcoal
16. filtrationThe latter was filtered off
17. customthe filtrate was evaporated
18. customThe residue was crystallized from 2,2'-oxybispropane

ORD record

ord-b8c3c49dbf0f4c3d9c3e82d55c8e2b9c

Source dataset

uspto-grants-1986_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04581171