2-Aminopyridine → 2-Chloromethyl-imidazo(1,2-A)pyridine

Participants

Reaction Steps

To a solution of 1,3-dichloropropan-2-one (1.40 g, 11 mmol) in 1,2-dimethoxyethane (5 mL), pyridin-2-amine (0.94 g 10 mmol) was added. The solid dissolved immediately and a white precipitate was observed. The mixture was stirred at room temperature for 1 h, and then was cooled to 0° C. for 20 min. The resulting mixture was filtered to give a white solid. The precipitate was suspended in ethanol (EtOH) (40 mL) and heated at reflux to render a clear solution. After refluxing for 2 h, the reaction mixture was concentrated under reduced pressure. The residue was dissolved in water and saturated aqueous NaHCO3 solution was added to adjust the pH to ˜7.0. A white suspension formed during the course of addition. The resulting mixture was stirred for 20 min and then filtered to give the title compound as a white solid (0.5 g, 30% yield). ESI MS: m/z 167 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ 8.49 (d, J=6.8 Hz, 1H), 7.97 (s, 1H), 7.49 (d, J=8.8 Hz, 1H), 7.23 (t, J=7.6 Hz, 1H), 6.88 (t, J=6.4 Hz, 1H), 4.82 (s, 2H).

Provenance & Evidence