Ethanol → HCID 21993700, compound

Participants

Reaction Steps

A solution of 5.0 g (21.16 mmol.) of 1-benzoylpiperazine formate, 5.97 g (21.16 mmol.) of 4-bromobutylphthalimide and 9.0 ml (64.57 mmol.) of triethylamine in ethanol (50 ml) was heated for 40 hours under reflux. The reaction mixture was cooled to room temperature, to which was added water. The mixture was subjected to extraction with ethyl acetate. The organic layer was washed with a saturated aqueous saline solution, which was then dried over magnesium sulfate, followed by distilling off the solvent under reduced pressure to leave a crude product. The crude product was purified by means of a column chromatography (methanol/ethyl acetate 5-10%). The solvent was distilled off under reduced pressure to give N-[4-(4-benzoylpiperazin-1-yl)butan-1-yl]phthalimide (6.99 g) as yellow oil. To a solution of 6.99 g of this compound in ethanol (50 ml) was added, at room temperature, 1.34 g (26.8 mmol.) of hydrazine monohydrate. The mixture was heated for 2 hours under reflux. The reaction mixture was cooled to room temperature. The resulting white solid substance was filtered off, and the filtrate was concentrated under reduced pressure. To the concentrate was added water, which was subjected to extraction with chloroform. The organic layer was washed with a saturated aqueous saline solution, which was dried over magnesium sulfate, followed by distilling off the solvent under reduced pressure to leave crude 4-(4-aminobutan-1-yl)-1-benzoylpiperazine. To an ethanol solution of this compound was added, at room temperature, 5 ml (60 mmol.) of 12N hydrochloric acid. The mixture was stirred for one hour at room temperature. The reaction mixture was concentrated under reduced pressure, to which was added diethyl ether. The resulting crystals were collected by filtration and washed with ethanol and diethyl ether to give the object compound as a white crystalline product. The yield was 2.92 g (41%).

Provenance & Evidence