A Grignard solution is prepared by introducing methyl chloride into a boiling
suspension of 36 g of magnesium in 1,000 cc of absolute ether until all the
magnesium has reacted. 216 grams of 4-chloro-benzophenone are slowly
added to the Grignard solution with ice cooling and stirring; after 15 hours,
the thus-obtained product is poured into a mixture of 200 g of ammonium
chloride and ice, whereupon it is separated with ether. The separated ether
layer is dried with sodium sulfate, and the ether is distilled. The residual
carbinol is added to a suspension of 45 g of sodium amide in 500 cc of
toluene. To the thus-obtained mixture there are added 125 g of
dimethylaminoethyl chloride, and the mixture is heated at boiling temperature
for 3 hours with stirring.
The mixture is taken up with water and the base is extracted from the toluene
with dilute hydrochloric acid. The hydrochloric solution is rendered alkaline
with caustic soda, the base is separated with ether, dried, and after distillation
of the ether fractionated in vacuo, BP at 0.05 mm Hg, 150° to 153°C. The
basic ether is then dissolved in dry ether, and ether saturated with dry
hydrogen chloride is added dropwise with stirring. An excess of hydrogen
chloride must be avoided as it may produce decomposition to the
corresponding diphenyl ethylene. The ether-moist hydrochloride is preferably
dried at once in vacuo and subsequently reprecipitated from acetone-ether
and then again dried in vacuo over phosphorus pentoxide. Hydrochloride, MP
128°C.
