134-32-7

20191-76-8

General procedure for the synthesis of 2,4-dibromo-1-aminonaphthalene from 1-naphthylamine: a mixture of 1-naphthylamine (286 mg, 2 mmol), potassium bromide (309 mg, 2.6 mmol), acetic acid (9 mL), water (1 mL), and dichloromethane (5 mL) was added sequentially to a three-necked flask equipped with a condenser and a thermometer. ZnAl-BrO3-LDHs (3.6 g, 3.6 mmol) was slowly added over 15 min in a thermostatically heated magnetic stirring water bath. The reaction temperature was controlled to be 25 °C for 5 h. The reaction was carried out at a constant temperature with magnetic stirring. After completion of the reaction, the reaction mixture was washed with sodium sulfite solution. It was subsequently extracted with dichloromethane (3 × 10 mL), the organic phases were combined and silica gel (200-300 mesh) was added to the organic phase. The organic solvent was removed by distillation under reduced pressure and the residue was purified by column chromatography (eluent was petroleum ether: ethyl acetate = 13:1) to afford 566 mg of the target product 2,4-dibromo-1-aminonaphthalene as a reddish brown solid in 94% yield.