4-Fluorobenzoic acid

4-Fluorobenzoic acid (p-fluorobenzoic acid) is an organic compound with the formula C7H5FO2. This colourless solid is a derivative of benzoic acid carboxylic acid. It is a synthetic intermediate.

4-Fluorobenzoic acid
4-fluorobenzoic acid-3D-balls.png
IUPAC name
4-Fluorobenzoic acid
Systematic IUPAC name
4-Fluorobenzoic acid
Other names
p-fluorobenzoic acid, para-fluorobenzoic acid, 4-fluoro-benzoic acid
3D model (JSmol)
ECHA InfoCard 100.006.600
EC Number
  • 207-259-0
Molar mass 140.113 g·mol−1
Appearance white solid
Density 1.479 g/cm3
Melting point 184 °C (363 °F; 457 K)
Boiling point 253.687 °C (488.637 °F; 526.837 K) at 760 mmHg
1200 mg/L
log P 2.07
Acidity (pKa) 4.14
Main hazards Irritates lungs, eyes, skin
Flash point 107.226 °C (225.007 °F; 380.376 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references


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.[1]


4-Fluorobenzoic acid has been observed to form by the aerobic biotransformation of 4-fluorocinnamic acid.[2]

See alsoEdit


  1. ^ G. Schiemann; W. Winkelmüller (1943). "p-Fluorobenzoic Acid". Organic Syntheses.; Collective Volume, 2, p. 299
  2. ^ Freitas Dos Santos, Luisa M.; Spicq, Arnaud; New, Anthony P.; Lo Biundo, Giuseppe; Wolff, Jean-Claude; Edwards, Andrew (2001). "Aerobic biotransformation of 4-fluorocinnamic acid to 4-fluorobenzoic acid". Biodegradation. 12 (1): 23–9. doi:10.1023/A:1011973824171. PMID 11693292.