Alfentanil hydrochloride

Chemical Name N-[1-[2-(4-Ethyl-4,5-dihydro-5-oxo-1 H-tetrazol-1-yUethyl] -4-(methoxy-methyl)-4-piperidinyl] -N-phenylpropaneamide hydrochloride 

Trade Name Manufacturer Country Year Introdu 

A mixture of 22 parts of 1-ethyl-1,4-dihydro-5H-tetrazol-5-one,45 parts of l-bromo-2-chloro-ethane, 26 parts of sodium carbonate, 0.3 part of potassium iodide and 240 parts of 4-methyl- 

2-pentanone is stirred and refluxed overnight with water-separator. The reaction mixture is cooled, water is added and the layers are separated. The aqueous phase is extracted three times with dichloromethane. The combined organic phases are dried, filtered and evaporated. The residue is purified by column-chromatography over silica gel using trichloromethane as eluent. The pure fractionsare collected and the eluent is evaporated,yielding 28.4 parts (80%) of 1-(2-chloroethyl)-4-ethyl-1,4-dihydro-5H-tetrazol-5-one as a residue. 

A mixture of 1.8 parts of 1 -(2-chloroethyl )-4-ethyl-1,4-dihydro-5H-tetrazol-5-one, 3.45 parts of N-[4-(methoxymethyl )-4-piperidinyl ] -N-phenylpropanamide, 5 parts of sodium carbonate, 0.2 part of potassium iodide and 240 parts of 4-methyl-2-pentanone is stirred and refluxed overnight with water-separator. The reaction mixture is poured onto water and the layers are separated. The organic phase is dried, filtered and evaporated. The residue is purified by column-chromatography over silica gel using a mixtu re of trichloromethane and methanol (97 3 by volume) as eluent. The pure fractions are collected and the eluent is evaporated. The residue is converted into the hydrochloride salt in 2-propanone. The salt is filtered off and crystallized from 2-propanone,yielding 1.5 parts (33.3%) of N-[1-[2-(4-ethyl-4,5-dihydro-5-oxo-1H-tetra-zol-1-yl] -4-(methoxymethyl)-4-piperidinyl] -N-phenylpropanamide monohydrochloride monohydrate melting point 140.8°C. 

Chemical Name 3-Hydroxypregnane-11 0-dione Common Name Alphaxolone Structural Formula  

A solution of 3a-hydroxy-5a-pregn-16-ene-11.20-dione (200 mg) in freshly distilled tetrahy-drofuran (8 ml) with 5% palladium on carbon (100 ml) was hydrogenated until hydrogen uptake ceased. The mixture was filtered through a pad of kieselguhr and the tetrahydrofuran removed in vacuo to give 196 mg, MP 171 to 172.  

Pearce, D.R.and Phillips,G.H.,British Patent 1,317,184 May 16,1973 assigned to Glaxo Laboratories, Ltd. 

Chemical Abstracts Registry No. 23930-194 Trade Name Manufacturer 

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ALFENTANIL HYDROCHLORIDE As an analgesic adjunct given in incremental doses in the maintenance of anesthesia with barbiturate/nitrous oxide/oxygen. 

Opoid anesthestics alfentanil hydrochloride fentanyl citrate remifentanil hydrochloride sufentanil citrate... 

Larijani, G.E. and Goldberg, M.E. Alfentanil hydrochloride a new short-acting narcotic analgesic for surgical procedures, Clin. Pharm. 1987, 6, 275-282. 

Alfentanil Hydrochloride Alfentanil hydrochloride can cause drug dependence similar to that of opioid analgesics. Since this may cause irritation and related adverse effects, it is important to avoid skin contact and the inhalation of alfentanil hydrochloride particles to contain adverse effects. 

Infra-red Spectrum. Principal peaks at wavenumbers 1722,1654, 1252,1109, 715, 967 (alfentanil hydrochloride, KBr disk). 

Hydrocortisone Butyrate Buclizine 448.1 448.4 Benzethonium Chloride Pipamperone Hydrochloride 470.7 471.0 Enoxolone Alfentanil Hydrochloride... 

Drostanolone Propionate 135-140 Alfentanil Hydrochloride Iprindole Hydrochloride... 

Hydrochloride monohydrate, C21H 5 jCI NtOj. H 20, alfentanil hydrochloride, R 39209, Raptfen, Alfenta. Crystals from 2-propanone, mp 140.8 (Janssens, 1979) also reported as crystals from acetone, mp 138.4° (Janssens, 1986). Sol in water. LD i.v. in rats, dogs (mg/kg) 47.5, 20 (Nieme-geers, Janssen). 

Rapifen (Alfentanil hydrochloride). Janssen-Cilag Ltd. UK Summary of product characteristics, May 2007. 

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