Monoformylpiperazine is reacted molecule for molecule with 2,3,4-
trimethoxybenzyl chloride in the presence of 1 1/2 molecules of sodium
carbonate and in suspension in ethyl alcohol, during 2 to 3 hours.
The reaction product is filtered and the filtrate is evaporated in vacuo to
remove the alcohol. There remains an oily product from which the excess
formyl-ethylenediamine is removed by distillation under 1 mm Hg pressure up
to 125°C. The dark yellow, residual product is treated with 10% hydrochloric
acid at 100°C for 12 hours to eliminate the formyl group; it is evaporated to a
syrupy consistency and taken up with ethyl alcohol at the boiling point until
complete miscibility is attained; it is then discolored over carbon, filtered and
stored at low temperature.
The (2,3,4-trimethoxyphenyl) methylpiperazine hydrochloride precipitates as
white needles: the precipitate is drained and washed with anhydrous sulfuric
ether. Melting point: 222°C to 226°C.