A mixture of 0.1 mol of N-mono-1-p-chlorobenzohydrylpiperazine and 0.1 mol
of 1-chloro-2-(2-hydroxy-ethoxy)-ethane is heated for 3 hours to 150°C. The
mass is then taken up in 100 ml of benzene and 100 ml of a 10% aqueous
solution of NaOH; decanting takes place, and the benzene solution is washed
with water and the solvent is evaporated. Vacuum distilling of the residue
yields 1-p-chlorobenzohydryl-4-[2-(2-hydroxy-ethoxy)-ethyl]-piperazine, BP
220°C/0.5 mm Hg. The corresponding dihydrochloride is prepared by dissolving this base in about
twice its weight of alcohol, by treating it with excess of gaseous HCl and by
precipitating it with ether. The solvent is decanted and the residue, dissolved
in a minimum of alcohol, crystallizes on the addition of ether, MP 193°C.
