Piperidine-catalyzed condensation of ethyl cyanoacetate with (I) (1) afforded cyanoester (II). Michael addition of KCN to (II) gave dinitrile (III), which was hydrolyzed under basic conditions to afford diacid (IV). Condensation of (IV) with N,N-diethylaminopropylamine afforded the desired imide (V). Reduction of (V) with lithium aluminum hydride gave the required diamine which was treated with aqueous HCl/n-propanol to yield the diamine as the dihydrochloride salt, SK&F 106615-A2 (VI).