N,N-Dioctadecyl-1,3-propanediamine:
A). A two-gallon autoclave is charged with 3-(dioctadecylamino)propionitrile
(100 g), ethanol (3750 ml) containing anhydrous ammonia (100 g) and Raney
nickel (20 g dry basis) and purged with nitrogen, then with hydrogen. It is
then sealed and the hydrogen pressure raised to 250 psi. The autoclave is
agitated, the temperature raised to 70°C and the mixture held at this
temperature for 1.5 hours at which time hydrogen absorption has ceased. The
autoclave is cooled to 20°C, vented, and the contents removed. The catalyst
is filtered off, washed with ethanol, and the combined washings and reaction
mixture concentrated in vacuum to a viscous green-yellow oil (82 g) which
solidified upon standing, MP: 39°-41°C.
3-(Dioctadecylamino)propionitrile is prepared by refluxing a mixture of
dioctadecylamine (200 g) and acrylonitrile (1903.8 ml) for eighteen hours.
The mixture is then concentrated to a waxy semi-solid which is slurried in
acetone, filtered, and air dried overnight.
B). The monoacyl derivatives of N,N-dioctadecyl-1,3-propanediamine are
prepared as follows:
To a solution of methylene chloride (500 ml per 0.1 mole of reactants)
containing equimolar amounts of N,N-dioctadecyl-1,3-propanediamine and
triethylamine and cooled in an ice-bath is added an equimolar amount of the
appropriate acyl chloride in methylene chloride (25 ml per 0.1 mole of acyl
chloride) over a period of 15 minutes. The mixture is stirred for ten minutes
then brought to room temperature and stirred for one hour. The methylene
chloride phase is separated and extracted with water (3x25 ml). The water is in turn extracted with methylene chloride (2x25 ml) and the combined
methylene chloride phases dried (Na2SO4) then evaporated under reduced
pressure. The residue is taken up in benzene and the solution passed through
a silica gel column. The column is eluted with benzene, then with benzene
containing increasing amounts of ethyl acetate, e.g., 5, 10, 25, and 50 %.
The eluate is subjected to thin layer chromatography (ethyl acetate) and
those fractions, which show only one spot, combined and evaporated to give
N,N-dioctadecyl-N',N'-bis(2-hydroxyethyl)propanediamine M.P. 48.5°-49°C.
