It is prepared through the following sequence: The Strecker reaction of 3,4-dichlorobenzaldehyde (I) with sodium cyanide and NH4Cl affords alpha-amino-3,4-dichlorophenylacetonitrile (II) (HCl salt, m.p. 184-5 C), which is reduced with LiAlH4 to 2-amino-1-(3',4'-dichlorophenyl)ethylamine (III) (di HCl salt, m.p. 283-5 C). Finally compound (III) is cyclized with BrCN in benzene.