4-Fluorobutyrfentanyl

4-Fluorobutyrylfentanyl (also known as 4-FBF and p-FBF or para-fluorobutyrylfentanyl) is an opioid analgesic that is an analog of butyrfentanyl and has been sold online as a designer drug.^[1][2] It is closely related to 4-fluorofentanyl, which has an EC₅₀ value of 4.2 nM for the human μ-opioid receptor.^[3]

4-Fluorobutyrfentanyl

Legal status
Legal status	BR: Class F1 (Prohibited narcotics) CA: Schedule I DE: Anlage II (Authorized trade only, not prescriptible) UK: Class A US: Schedule I Illegal in China and Sweden
Identifiers
IUPAC name N-(4-Fluorophenyl)-N-[1-(2-phenylethyl)-4-piperidinyl]-butanamide
CAS Number	244195-31-1
PubChem CID	86280430
ChemSpider	32779976
UNII	2378L0E82T
KEGG	C22765
CompTox Dashboard (EPA)	DTXSID101032566
Chemical and physical data
Formula	C23H29FN2O
Molar mass	368.496 g·mol−1
3D model (JSmol)	Interactive image
SMILES CCCC(=O)N(C1CCN(CC1)CCC2=CC=CC=C2)C3=CC=C(C=C3)F
InChI InChI=1S/C23H29FN2O/c1-2-6-23(27)26(21-11-9-20(24)10-12-21)22-14-17-25(18-15-22)16-13-19-7-4-3-5-8-19/h3-5,7-12,22H,2,6,13-18H2,1H3 Key:QZFMCYUBPSLOBP-UHFFFAOYSA-N

Side effects

Side effects of fentanyl analogs are similar to those of fentanyl itself, which include itching, nausea and potentially serious respiratory depression, which can be life-threatening. Fentanyl analogs have killed hundreds of people throughout Europe and the former Soviet republics since the most recent resurgence in use began in Estonia in the early 2000s, and novel derivatives continue to appear.^[4]

Legal status

Sweden's public health agency suggested classifying 4-fluorobutyrylfentanyl as hazardous substance on August 18, 2014.^[5]

In October 2015, 4-fluorobutyrylfentanyl became a controlled substance in China.^[6]

4-Fluorobutyrfentanyl is a Schedule I controlled drug in the USA since 1. February 2018.^[7]

See also

• 3-Methylbutyrfentanyl
• 3-Methylfentanyl
• 4-Fluorofentanyl
• 4-Fluoroisobutyrfentanyl
• α-Methylfentanyl
• Acetylfentanyl
• Acrylfentanyl
• Furanylfentanyl
• List of fentanyl analogues