In a 2-liter, 3-necked, round-bottomed flask equipped with a stirrer, dropping
funnel, and a condenser protected with a calcium chloride drying tube is
placed 13.7 grams (0.57 mol) of magnesium turnings and the magnesium is
covered with 200 cc of anhydrous ether. A crystal of iodine is added to the
flask and 92.9 grams (0.57 mol) of cyclohexyl bromide dissolved in 300 cc of
anhydrous ether is added dropwise with stirring while the reaction proceeds.
After the addition of the cyclohexyl bromide is completed, the resulting
mixture is stirred and heated on a steam bath for 3 hours. The mixture is
cooled to room temperature and 49.5 grams (0.227 mol) of N-phenacyl-N'-
methylpiperazine dissolved in 50 cc of anhydrous ether is added dropwise and
the resulting mixture is stirred and re fluxed for about 16 hours.
The reaction mixture is cooled and 50 grams of ammonium chloride dissolved
in 200 cc of water is added dropwise thereto with stirring. The decomposed
Grignard complex is then filtered. Benzene is added to the ether filtrate and
the solvents are removed therefrom on a steam bath. The residue is
fractionated and the base, N-(β-cyclohexyl-β-hydroxy-β-phenyl-ethyl)N'-
methylpiperazine, is obtained as a liquid having a boiling point of 196° to
203°C at a pressure of 4.0 mm.
To 3.8 grams of the base dissolved in 35 cc of ethyl alcohol is added 1.6
grams of dimethyl sulfate. The solution is allowed to stand at room
temperature for about 12 hours. The salt formed is filtered, recrystallized from
ethyl alcohol, and is found to have a melting point of 203° to 204°C.
Hexocyclium, 4-(|?-cyclohexyl-|?-hydroxyphenethyl)-1,1-piperazinium
methylsulfate (14.1.28), is synthesized by alkylating 1-methylpiperazine with |á-bromacetophenone, which forms 4-methyl-1-phenacylpiperazine (14.1.26). Reacting this with
cyclohexylmagnesiumbromide gives 4-(|?-cyclohexyl-|?-hydroxyphenethyl)-1,1-piperazine (14.1.27), the alkylation of which using dimethylsulfate gives hexocyclium [23].
