Triethylamine → 1′-(4-Nitrophenyl)-1,4′-bipiperidine

Participants

Reaction Steps

A solution of 1-fluoro-4-nitrobenzene (1.3 mL, 12.3 mmol), triethylamine (6.0 mL; 43.0 mmol) and 4-(piperidin-1-yl)piperidine (2.36 g; 14.0 mmol) in dioxane (10 mL) was heated at reflux for 18 hr. After cooling to room temperature the mixture was concentrated under reduced pressure and the residue dissolved in DCM (150 mL). The DCM solution was washed with saturated aqueous sodium bicarbonate and brine, then dried over magnesium sulfate and concentrated under reduced pressure to produce a yellow solid. Hexanes were added and the suspension briefly sonicated. The solid was collected by filtration and washed with hexanes to give 1-(4-nitrophenyl)-4-(piperidin-1-yl)piperidine (3.05 g) as a yellow solid. A solution of 1-(4-nitrophenyl)-4-(piperidin-1-yl)piperidine (3.05 g; 10.5 mmol) in ethanol (20 mL) was hydrogenated at atmospheric pressure with 10% palladium on carbon (0.251 g) at room temperature for 17 hr. The mixture was filtered through diatomaceous earth and concentrated under reduced pressure to give 4-[4-(piperidin-1-yl)piperidin-1-yl]benzenamine (2.01 g) as a purple/pink solid.

Provenance & Evidence