1821-12-1

4-Phenylbutyric acid is white to slightly yellowish crystalline powder. It is slightly soluble in chloroform and methanol. Its solubility in water is 5.3 g/l (at 40 °C).

4-Phenylbutyric acid is used as a chemical chaperone involved in protein-folding disorders. It is involved in the synthesis of dyes and an active pharmaceutical ingredient intermediate.

4-Phenylbutyric acid is used as organic intermediates.

4-Phenylbutyric acid (4-PBA) is used in the treatment of urea cycle disorders under the trade name Buphenyl. 4-PBA has been used as a selective inhibitor of endoplasmic reticulum stress (ERS).
4-Phenylbutyric acid is used as organic intermediates. It can also be used as a reactant in the synthesis of:
1-Tetralone using Lewis acid catalyst.
4,N-diphenylbutyramide.

4-Phenylbutyric acid is a monocarboxylic acid the structure of which is that of butyric acid substituted with a phenyl group at C-4. It is a histone deacetylase inhibitor that displays anticancer activity. It inhibits cell proliferation, invasion and migration and induces apopto is in glioma cells. It also inhibits protein isoprenylation, depletes plasma glutamine, increases production of foetal haemoglobin through transcriptional activation of the gamma-globin gene and affects hPPARgamma activation.

4-phenylbutyric acid is obtained by the reaction of benzene with butyrolactone in the presence of aluminum chloride, followed by neutralization with base.
Synthesis of 4-phenylbutyric acid

Tetrahedron Letters, 32, p. 3309, 1991 DOI: 10.1016/S0040-4039(00)92693-5

4-Phenylbutyric acid (4-PBA) is a small-molecular-weight fatty acid with a terminal aromatic group, and its sodium salt (sodium 4-phenyl butyrate) has been used for the treatment of urea cycle disorders. This molecule is also used for the treatment of sickle cell diseases and thalassemia owing to its ability to activate β-globin transcription. Moreover, 4-PBA is employed as an orally bioavailable agent for the treatment of spinal muscular atrophy (SMA) and tumors.
Neuroprotective Effects of 4-phenylbutyric Acid and Its Derivatives: Possible Therapeutics for Neurodegenerative Diseases

Store at RT

Crystallise the acid from pet ether (b 40-60o). [Beilstein 9 IV 1811.]