1,2-Epoxy-3-(2-cyanophenoxy)propane (I) is added to one equivalent of N-(2-aminoethyl)-4-benzyloxyphenylacetamide (II) in n-propanol and heated to reflux for 18 h, giving N-[2-(3-o-cyanophenoxy-2-hydroxypropylamino)ethyl]-4-benzyloxyphenylacetamide (III). Hydrogenolysis of the 4-benzyl moiety of (III) may be performed under mild conditions (e.g., hydrogen gas with palladium on carbon in ethanol at room temperature) to yield ICI-141292.
The condensation of 1-(2-cyanophenoxy)-2,3-epoxypropane (I) with ethylenediamine (II) gives 1-(2-cyanophenoxy)-3-(2-aminoethylamino)-2-propanol (III), which is finally treated with phenyl isocyanate (IV) in acetonitrile.