236. Alfentanil

Nomenclature

CAS number: 71195-58-9
N-[1-[2-(4-Ethyl-4,5-dihydro-5-oxo-1H-tetrazol-1-yl)ethyl]-4-(methoxymethyl)-4-piperidinyl]-N-phenylpropanamide; N-[1-[2-(4-ethyl-5-oxo-2-tetrazolin-1-yl)ethyl]-4-(methoxymethyl)-4-piperidyl]propionanilide.
C21H32N6O3; mol wt 416.52.
C 60.56%, H 7.74%, N 20.18%, O 11.52%.

Description and references

Synthetic opioid analgesic; derivative of fentanyl, q.v. Prepn: F. Janssens, DE 2819873; idem, US 4167574 (1978, 1979 both to Janssen); F. Janssens et al., J. Med. Chem. 29, 2290 (1986). Pharmacology and acute toxicity: C. J. E. Niemegeers, P. A. J. Janssen, Drug Dev. Res. 1, 83 (1981). LC-MS/MS determn in urine: M. Thevis et al., Eur. J. Mass Spectrom. 11, 419 (2005). Review of pharmacology and clinical efficacy: G. E. Larijani, M. E. Goldberg, Clin. Pharm. 6, 275-282 (1987). Comparative review of clinical pharmacokinetics: J. Scholz et al., Clin. Pharmacokinet. 31, 275-292 (1996); and clinical uses: J. S. Willens, N. R. Myslinski, Heart Lung 22, 239-251 (1993).

Chemical structure

Derivative

Hydrochloride.

Nomenclature

CAS number: 69049-06-5; 70879-28-6 (monohydrate)
R-39209; Alfenta (Taylor Pharm.); Brevafen (Janssen-Cilag); Fentalim (Angelini); Limifen (Janssen-Cilag); Rapifen (Janssen-Cilag).
C21H32N6O3.HCl; mol wt 452.98.
C 55.68%, H 7.34%, N 18.55%, O 10.60%, Cl 7.83%.

Properties

White to almost white powder. Monohydrate, crystals from acetone, mp 138.4°. pKa 6.5. Partition coefficient (n-octanol/water): 128 (pH 7.4). Freely sol in methanol, ethanol, chloroform; sol in water; sparingly sol in acetone. LD50 in rats, dogs (mg/kg): 47.5, 20 i.v. (Niemegeers, Janssen).

Note

This is a controlled substance (opiate): 21 CFR, 1308.12.

Therapeutic Category

Analgesic; anesthesia adjunct.

Therapeutic Category (Veterinary)

Analgesic.

Keywords

Analgesic; Opioids; Phenylpiperidines