4-Fluorobenzoic acid is commercially available.
It may be prepared via the Schiemann reaction, in which a 4-aminobenzoic acid, protected as the ethyl ester, is diazotised and then fluoride introduced using tetrafluoroborate.
Hydrolysis of the ester converts it back to the free acid.

4-Fluorobenzoic acid has been observed to form by the aerobic biotransformation of 4-fluorocinnamic acid.
4-Fluorobenzoic acid is commercially available. It may be prepared via the Schiemann reaction, in which a 4-aminobenzoic acid, protected as the ethyl ester, is diazotised and then fluoride introduced using tetrafluoroborate. Hydrolysis of the ester converts it back to the free acid.
4-Fluorobenzoic acid has been observed to form by the aerobic biotransformation of 4-fluorocinnamic acid.
4-Fluorobenzoic acid