To a stirred solution of phenacyl bromide (1 mmol, 1 equiv) in diethyl ether (13 mL) was added hexamethylenetetramine (1 mmol, 1 equiv) all at once and the mixture was stirred for 12 h at room temperature. The resulting solid was filtered, washed with diethyl ether (15 mL), and dried under reduced pressure to afford the quaternary salt, which was next placed in a two-necked round-bottomed flask fitted with a reflux condenser, and EtOH (22 mL) was added to it. Concentrated HCl (0.6 mL) was added, and the mixture was refluxed for 3 h (solid formed). After cooling to room temperature, the solid was filtered, washed with EtOH (20 mL), and dried under vacuum to afford pure 2-Aminoacetophenone hydrochloride.
