1-benzyl-3-bromopyrrolidin-2-one

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 3-bromo-1-benzyl-pyrrolidin-2-one (1.4 g, 5.1 mmol)(intermediate 3), 4-(4-methoxyphenyl)-piperidine (0.98 g, 5.1 mmol) and DIPEA (3.6 mL, 20.6 mmol) in acetonitrile (15 mL) was heated at 90° C. for 18 h. The reaction mixture was concentrated and the residue was dissolved in ethyl acetate (150 mL), washed with water and brine, and dried over sodium sulfate. The organic layer was concentrated to yield 2.1 g of crude product, which was purified by flash chromatography on silica gel (24 g) using 100% EtOAc to yield 1-benzyl-3-(4-(4-methoxyphenyl)piperidin-1-yl)pyrrolidin-2-one (1.4 g, 71%). 1H NMR: 400 MHz, DMSO-d6: δ ppm 1.51-1.65 (m, 2H) 1.66-1.77 (m, 2H) 1.86-1.98 (m, 1H) 2.02-2.12 (m, 1H) 2.27-2.45 (m, 2H) 2.66-2.83 (m, 2H) 2.99-3.23 (m, 3H) 3.45-3.54 (m, 1H) 3.72 (s, 3H) 4.29-4.46 (m, 2H) 6.85 (d, J=9.04 Hz, 2H) 7.16 (d, J=9.04 Hz, 2H) 7.19-7.24 (m, 2H) 7.28 (s, 1H) 7.32-7.39 (m, 2H). LCMS: R.T. 1.76 min. LCMS (ES-API), 365.2 m/z (M+H). The reaction mixture was concentrated the residue was dissolved in ethyl acetate (150 mL) washed with water and brine dried over sodium sulfate The organic layer was concentrated to yield 2.1 g of crude product, which was purified by flash chromatography on silica gel (24 g)