1-Benzyl-3-phenylpiperidin-4-one

To a mixture of 5 (122.7 g, 0.418 mol) and sodium bicarbonate (88.6 g, 0.836 mol) in CH3CN (328 mL) was added benzyl bromide (78.7 g, 0.459 mol) at room temperature, and then the mixture was stirred at 70 °C for 2 h. The insoluble material was filtered off, and then the filtrate was concentrated. The residue was dissolved in EtOAc (500 mL), and the solution was washed with aqueous NH4Cl and brine, dried and concentrated to give an oil (166.5 g). The oil was dissolved in EtOH (180 mL). The solution was slowly added to a cooled suspension of sodium hydride (60percent in oil dispersion, 34.7 g, 0.867 mol) in toluene (281 mL) at -5 °C, and then the mixture was heated at 75 °C for 2 h. The reaction mixture was poured into H2O, and then the mixture was extracted with EtOAc (500 mL .x. 2). The extract was washed with aqueous NH4Cl and brine, dried and concentrated to give a brown oil (151.8 g). The obtained oil was dissolved in AcOH (250 mL) and concentrated HCl (250 mL), and then the mixture was heated at 125 °C for 3 h. More AcOH (150 mL) and concentrated HCl (150 mL) were added thereto, and the stirring was continued at 125 °C for 2 h. The solvents were evaporated, and then the residue was dissolved in EtOAc (500 mL). The solution was made basic with 12 N NaOH, and extracted with EtOAc (.x.2). The extract was washed with aqueous NH4Cl and brine, dried and concentrated to give an oil, which was treated with 4 N HCl-EtOAc (100 mL) and the resulting precipitate was collected by Et2O to provide 6 (104.9 g, 83percent) as white powder. 1H NMR (CDCl3) delta: 2.60-2.70 (1H, m), 3.15-3.40 (2H, m), 3.60-3.90 (3H, m), 4.03 (2H, s), 4.86 (1H, dd, J = 12.4, 5.4 Hz), 7.11-7.15 (2H, m), 7.30-7.40 (3H, m), 7.40-7.55 (3H, m), 3.60-7.70 (2H, m). The NMR spectrum was measured as a free base.

Molecular Weight:265.3
XLogP3:2.9
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:3
Exact Mass:265.146664230
Monoisotopic Mass:265.146664230
Topological Polar Surface Area:20.3
Heavy Atom Count:20
Complexity:315
Undefined Atom Stereocenter Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes