To a 1000 mL four-necked flask was added hydroxylamine hydrochloride (48.7 g, 0.70 mol, 1.4 eq.), water (50 g), and ethanol (200 g, 2.3 times the volume), and stirred at room temperature until hydroxylamine hydrochloride was completely dissolved. Ethyl octanoate (86.7 g, 0.5 mol, 1.0 eq.) was then added and stirred at room temperature to form a two-phase system. The reaction mixture was cooled to 5-10°C and 40% KOH solution (168 g, 1.2 mol, 2.4 eq.) was added slowly and dropwise. After the dropwise addition, the reaction system was heated to 50~55°C and the reaction was held for 3 hours and monitored by gas chromatography (GC) until the ethyl octanoate material completely disappeared. After the reaction was completed, cooled to 5~10°C, slowly added concentrated hydrochloric acid (90 mL) to adjust the pH to 6.4~6.7, at which time a large amount of white solid precipitated. The solid was collected by filtration and dried at 50°C for 8 hours. The crude product was recrystallized with benzene to give 78.8 g of white flocculent solid in 91.1% yield.
