The reaction of 2-chlorophenylacetonitrile (I) with 2-chloroethyldiisopropylamine (II) by means of NaNH2 in hot toluene gives alpha-[2-(diisopropylamino)ethyl]-2-chloroethyl-2-chlorophenylacetonitrile (III), which is condensed again with 1-(2-chloroethyl)piperidine (IV) by means of NaNH2 in the same way to afford alpha-[2-(1-piperidino)ethyl]-alpha-[2-(diisopropylamino)ethyl]-2-chlorophenylacetonitrile (V). Finally this compound is hydrolyzed partially by means of H2SO4 at 0 C.