4-Fluorophenibut

4-Fluorophenibut (developmental code name CGP-11130; also known as β-(4-fluorophenyl)-γ-aminobutyric acid or β-(4-fluorophenyl)-GABA) is a GABA_B receptor agonist which was never marketed.^[1] It is selective for the GABA_B receptor over the GABA_A receptor (IC₅₀ = 1.70 μM and > 100 μM, respectively).^[1] The drug is a GABA analogue and is closely related to baclofen (β-(4-chlorophenyl)-GABA), tolibut (β-(4-methylphenyl)-GABA), and phenibut (β-phenyl-GABA).^[1] It is less potent as a GABA_B receptor agonist than baclofen but more potent than phenibut.^[1]

4-Fluorophenibut

Clinical data
Other names	CGP-11130; β-(4-Fluorophenyl)-γ-aminobutyric acid; β-(4-Fluorophenyl)-GABA; Baflofen; Fluorophenibut; F-Phenibut; Fluoribut
Routes of administration	By mouth
Identifiers
IUPAC name 4-Amino-3-(4-fluorophenyl)butanoic acid
CAS Number	52237-19-1
PubChem CID	103611
ChemSpider	93547
UNII	6DAU7M5P3D
CompTox Dashboard (EPA)	DTXSID00966612
Chemical and physical data
Formula	C10H12FNO2
Molar mass	197.209 g·mol−1
3D model (JSmol)	Interactive image
SMILES C1=CC(=CC=C1C(CC(=O)O)CN)F
InChI InChI=1S/C10H12FNO2/c11-9-3-1-7(2-4-9)8(6-12)5-10(13)14/h1-4,8H,5-6,12H2,(H,13,14) Key:QWHXHLDNSXLAPX-UHFFFAOYSA-N

The substance is sometimes referred to as 4F-phenibut, F-phenibut, or baflofen, and colloquially as fluorobut.

Legal status

F-Phenibut is a prohibited substance in Lithuania^[2] and Hungary.^[3]