Potassium Carbonate → 4,4-bis(4-methoxyphenyl)piperidine

Participants

Reaction Steps

4,4-bis-(4-Methoxyphenyl)piperidine (9.01 g, 30.3 mmol, 1.00 equiv), 3-bromopropylamine hydrobromide (6.66 g, 30.3 mmol, 1.00 equiv) and potassium carbonate (5.02 g, 36.3 mmol, 1.20 equiv) were stirred in refluxing anhydrous 1,4-dioxane (200 mL) for 12 hours. After removal of dioxane, water (200 mL) was added and the pH was adjusted to 11-12 by addition of 1 N aqueous NaOH. The mixture was extracted with CH2 Cl2 (4×200 mL). The combined organic solutions were dried over MgSO4 and concentrated. The residue was purified by flash chromatography (SiO2, CHCl3 -MeOH-NH3 (2M in MeOH) 100:20:10) to give 6.50 g of 4,4-bis-(4-methoxyphenyl)piperidine and 2.70 g (25%, 90% after correction for recovered starting material) of 1-(3-aminopropyl)-4,4-bis-(4-methoxyphenyl)piperidine (colorless oil), which was characterized spectroscopically.

Provenance & Evidence