4-Methoxybenzaldehyde → 1-Tert-butyl 4-methyl 4-((4-methoxybenzylamino)methyl)piperidine-1,4-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

Commercial available 1-tert-butyl 4-methyl 4-(aminomethyl)piperidine-1,4-dicarboxylate (10.10 mmol, 2.75 g) and 4-methoxybenzaldehyde (15.15 mmol, 2.062 g) in anhydrous MeOH (40 mL) were stirred for 2 h at rt. After addition of sodium cyanoborohydride (20.19 mmol, 1.269 g) the reaction was stirred overnight at 45° C. The mixture was evaporated in vacuo, and solved in EtOAc and sat. aq. bicarb. After separation of the organic phase, the aq. phase was extracted with EtOAc. The combined organic phase was dried over MgSO4 and evaporated in vacuo. The crude was purified by flash chromatography (heptane/EtOAc: 10 to 100%) yielding 2.3 g oil (58%). 1H NMR (400 MHz, CDCl3, 300K): δ=1.40 (2H, s), 1.45 (9H, s), 2.07 (2H, dt, J=13.3 Hz, J=3.4 Hz), 2.66 (2H, m), 2.94 (2H, m), 3.68 (2H, s), 3.70 (3H, s), 3.76 (2H, m), 3.79 (3H, s), 6.85 (2H, d, J=8.3 Hz), 7.19 (2H, d, J=8.3 Hz). 13C NMR (100 MHz, CDCl3, 300K): δ=28.8, 31.9, 47.3, 52.3, 53.9, 55.7, 57.3, 79.8, 114.0, 129.4, 132.8, 155.2, 159.0, 176.1. MS (ES) C21H32N2O5 requires: 392. found: 393.3 [M+H]+.

Provenance & Evidence