p-Toluenesulfonic acid → N-(3-phenylpropyl)-5-imidazol-1-ylpentylamine

Participants

Reaction Conditions

Reaction Steps

A mixture of 1-(5-aminopentyl)imidazole (3.48 g), 3-phenylpropionaldehyde (3.08 g), p-toluenesulphonic acid (0.1 g) and toluene (90 ml) was boiled under reflux whilst removing the water formed using a Dean & Stark apparatus under nitrogen for 2 hours. The mixture was evaporated to dryness under reduced pressure to give an oil which was dissolved in IMS (100 ml) and cooled to 5° C. under nitrogen. Sodium borohydride (0.87 g) was added to the solution with stirring. The mixture was allowed to warm to 20° C. and stirred at this temperature for 16 hours. The solvent was removed under reduced pressure. The residue was dissolved in water and acidified to pH 2 with 2M hydrochloric acid. The solution was then basified with 2M sodium hydroxide solution (100 ml) and extracted with ethyl acetate to give an oil. The oil was distilled under high vacuum b.p. 250° C. at 0.04 mbar. The distillate was purified by flash column chromatography on silica using ethyl acetate/methanol/triethylamine (80:10:10) as the mobile phase to give N-(3-phenylpropyl)-5-imidazol-1-ylpentylamine 0.75 hydrate.

Provenance & Evidence