During the course of conversion of secondary to tertiary bases by cyanoethylation it was found that the tertiary cyanoethylamines were considerably weaker bases than the secondary amines and about 3 pK units weaker than the corresponding tertiary ethylamines. That the highly electron-withdrawing cyano group should exert a base-weakening effect was to be anticipated but its magnitude was surprising.
![3-[(1-methyl-2-phenylethyl)amino]propiononitrile Structure](https://image.chemsrc.com/caspic/353/16397-28-7.png)
