Dialkylation reaction of commercially available cyanamid with the corr
esponding bromomethyl compounds proceeds smoothly in the presence of a
phase-transfer catalyst in a mixture of toluene-water or dichlorometh
ane-water under mild alkaline conditions, and affords N,N'-dicyano[3.3
]azacyclophanes and their higher homologs in good to moderate yields.
The two-step reaction involving the coupling followed by decyanation o
f the N-cyano groups provides a new, simple, synthetic method of azacy
clophanes, especially for the sterically constrained or acid sensitive
azacyclphanes.