GENERAL STEPS: 2-methoxyethylamine (12.5 mmol) was added slowly and dropwise to a stirring solution of 2,3-dichloro-1,4-naphthoquinone (10 mmol) and triethylamine (1 mL) in N,N-dimethylformamide (DMF, 20 mL) under ice bath conditions. After the color of the reaction mixture changed from light yellow to red, the ice bath was removed and the reaction continued to be stirred for 1 h at room temperature. Subsequently, the reaction solution was poured into 300 mL of water and an orange-red precipitate precipitated. The precipitate was collected by filtration, washed with cold water and dried to obtain the target product 2-chloro-3-((2-methoxyethyl)amino)naphthalene-1,4-dione. Yield: 96.1%; Appearance: orange powder; Melting point: 82-83 °C; 1H NMR (DMSO-d6, 400 MHz) δ: 7.98 (m, 2H), 7.75-7.87 (m, 2H), 7.25 (s, 1H), 3.92-3.94 (m, 2H), 3.57 (t, J = 5.7 Hz, 2H), 3.29- 3.38 (s, 3H); ESI-MS: m/z 266.1 [M + H]+, C13H12ClNO3 (MW = 265.1).
