The quaternary salt (II), prepared from 1-(pyrimidin-2-yl)piperazine (I) and 1,4-dibromobutane (A), undergoes reaction with 3,3-dimethylglutarimide (III) in the presence of potassium carbonate in refluxing xylene to afford the free base (IV), which is isolated by acid extraction and basification of the extract. Treatment of the free base with HCl in isopropanol affords ttle compound as the monohydrochloride.
This compound has been obtained by two related ways: The reduction of 4-[4-(2-pyrimidinyl)piperazin-1-yl]butyronitrile (I) by means of RaNi and hydrazine in isopropanol gives 4-[4-(2-pyrimidinyl)piperazin-1-yl]butylamine (II), which is then condensed with 3,3-dimethylglutaric anhydride (III) in refluxing xylene or refluxing toluene to yield the target glutarimide derivative. Alternatively, the condensation of N-(4-bromobutyl)-3,3-dimethylglutarimide (IV) with 1-(2-pyrimidinyl)piperazine (V) by means of K2CO3 in refluxing acetonitrile also yields the target glutarimide derivative.