36637-18-0

Duranest,Astra,US,1976

Anesthetic (local).

ChEBI: An amino acid amide in which 2-[ethyl(propyl)amino]butanoic acid and 2,6-dimethylaniline have combined to form the amide bond. Used as a local anaesthetic (amide caine), it has rapid onset and long action properties, similar to bupivacaine, and is given b injection during surgical procedures and during labour and delivery.

α-(n-Propylamino)-n-butyro-2,6-xylidide(0.243 mol) and freshly distilled diethyl sulfate (1.6 mols were mixed in a flask equipped with reflux condenser, drying tube and stirrer. The mixture was stirred for 5 hours at 90°C. After cooling, water (110 ml) was added with stirring for 15 minutes followed by 4M HCl (110 ml). The solution was washed with ether (3 X 100 ml) and made alkaline with 7M NaOH to pH 10-11. The freed base was taken up in ether (3 X 100 ml); the extracts were dried over sodium sulfate, filtered and evaporated. The residue was dissolved in absolute ether (200 ml) and the hydrochloride prepared by addition of ethereal hydrogen chloride. The precipitate was filtered, washed with ether, and recrystallized twice from absolute ethanol/ether and from isopropanol/isopropylether; MP 203°C to 203.5°C; yield: 0.126 mol (52%). The starting material is prepared by reacting 2-bromobutyric acid with sulfonyl chloride to give the acid chloride. It is then reacted with 2,6-xylidine, then with potassium iodide followed by n-propylamine.

Duranest [as hydrochloride] (Astra).

Local anesthetic