Acetic Acid → Ammonia

Participants

Reaction Steps

3-Methyl-4-(piperidin-4-yloxy)-benzofuran-2-carboxylic acid ethyl ester (44 mg), pyridine-3-aldehyde (41 μl) and acetic acid (50 μl) were dissolved in THF (2 ml). The solution was stirred at room temperature for one hour. To a solution was added NaB(OAc)3H (160 mg) and the resulting suspension was stirred at room temperature for two hours. The reaction mixture was diluted with ethyl acetate and washed with saturated sodium hydrogencarbonate solution and water. The organic solvent was dried over anhydrous sodium sulfate and evaporated to dryness. The residue was purified by preparative thin layer chromatography (using dichloromethane:MeOH:ammonia solution (25-28%)=10:1:0.2 as a developing solvent) to give 3-methyl-4-(1-pyridin-3-ylmethyl-piperidin-4-yloxy)-benzofuran-2-carboxylic acid ethyl ester (44 mg) as a colorless oil. MALDI-TOF-MS: m/z 395 (MH+); 1H-NMR (CDCl3): δ 1.44 (3H, t, J=7 Hz), 2.02 (4H, m), 2.47 (2H, m), 2.72 (2H, m), 2.75 (3H, s). 3.56 (2H, s), 4.44 (2H, q, J=7 Hz), 4.58 (1H, m), 6.62 (1H, d, J=8 Hz), 7.09 (1H, d, J=8 Hz), 7.28 (1H, t, J=8 Hz), 7.29 (1H, m), 7.71 (1H, brd, J=8 Hz), 8.53 (1H, brd, J=4 Hz), 8.56 (1H, br s).

Provenance & Evidence