To the solution of 2-cyano-N-(1-(4-(2-(diethylamino)ethoxy)phenyl)butyl)acetamide (29; 116 mg, 0.35 mmol) in ethanol (2 mL) was added β-alanine (499 mg, 5.6 mmol) and water (2 mL). 6-Bromopicolinaldehyde (260 mg, 1.4 mmol) was added, and the resulting mixture was then stirred at room temperature for 18 hours. The reaction mixture was diluted with ethyl acetate, washed with sat. aqueous NaHCO3 (2×) and sat. brine, dried over sodium sulfate, and concentrated to a crude solid. Purification by flash silica gel column chromatography, eluting with 5:95 methanol/dichloromethane, afforded 33 (140 mg, 80%) as a thick yellow oil: MS (ES+) m/z=499.1 (M+H)+.
