Propanal → 1-Benzyl-4-[N-ethyl-N-(3-propylamino-2-pyridinyl)amino]piperidine

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Reaction Steps

1-Benzyl-4-[N-ethyl-N-(3-amino-2-pyridinyl)amino]piperidine (EXAMPLE 204B, 6.37 g, 20.56 mmol) and propionaldehyde (1.63 ml, 22.6 mmol) are dissolved in 50 ml methanol and cooled to 0°. Sodium cyanoborohydride (1.42 g, 22.6 mmol) is added and the mixture is warmed to 20°-25°. Twice more propionaldehyde (22.6 mmol) and sodium cyanoborohydride (22.6 mmol) are added, cooling the mixture to 0° before and warming to 20°-25° after each addition. The mixture is stirred 16 hr, then poured into 1N sodium hydroxide and extracted with dichloromethane. The extract is dried over sodium sulfate, filtered and concentrated. Chromatography (silica gel, 300 g; ethyl acetate/hexane (25/75)), gives the title compound, NMR (400 MHz, CDCl3) 7.72, 7.30, 6.91, 6.78, 4.79, 3.49, 3.14, 3.04, 2.87, 1.98, 1.73, 1.63, 1.01 and 0.86δ.

Provenance & Evidence