Title: Furethidine
CAS Registry Number: 2385-81-1
CAS Name: 4-Phenyl-1-[2-[(tetrahydro-2-furanyl)methoxy]ethyl]-4-piperidinecarboxylic acid ethyl ester
Additional Names: 4-phenyl-1-[2-(tetrahydrofurfuryloxy)ethyl]isonipecotic acid ethyl ester; ethyl 1-(tetrahydrofurfuryloxyethyl)-4-phenylpiperidine-4-carboxylate; 1-(2¢-tetrahydrofurfuryloxyethyl)norpethidine
Molecular Formula: C21H31NO4
Molecular Weight: 361.48
Percent Composition: C 69.78%, H 8.64%, N 3.87%, O 17.70%
Literature References: Prepn: Frearson, Stern, GB 797448 (1958 to J. F. Macfarlan & Co.); Frearson et al., J. Chem. Soc. 1960, 2103.
Properties: bp0.5 210°; bp0.3 175-183°. mp ~28°. nD20 1.5219. pKa 7.48.
Melting point: mp ~28°
Boiling point: bp0.5 210°; bp0.3 175-183°
pKa: pKa 7.48
Index of refraction: nD20 1.5219
Derivative Type: Methiodide
Molecular Formula: C22H34INO4
Molecular Weight: 503.41
Percent Composition: C 52.49%, H 6.81%, I 25.21%, N 2.78%, O 12.71%
Properties: Crystals from ethyl acetate, mp 174°.
Melting point: mp 174°
NOTE: This is a controlled substance (opiate): 21 CFR, 1308.11.
Furfural Furfuryl Alcohol Furfurylmethylamphetamine Furonazide Furoyl Chloride

Systematic (IUPAC) name
ethyl 1-[2-(oxolan-2-ylmethoxy)ethyl]-4-phenylpiperidine-4-carboxylate
Clinical data
Legal status Prohibited (S9) (AU) Class A (UK) Schedule I (US)
CAS number 2385-81-1
ATC code None
PubChem CID 61306
DrugBank DB01464
ChemSpider 55245 YesY
Synonyms ethyl 4-phenyl-1-(2-tetrahydrofurfuryloxyethyl)piperidine-4-carboxylate
Chemical data
Formula C21H31NO4 
Mol. mass 361.48 g/mol
 YesY (what is this?)  (verify)

Furethidine is a 4-phenylpiperidine derivative that is related to the opioid analgesic drug pethidine (meperidine).[1]

Furethidine is not currently used in medicine and is a Class A/Schedule I drug which is controlled under UN drug conventions. It has similar effects to other opioid derivatives, such as analgesia, sedation, nausea and respiratory depression.[2]