99-40-1

120-80-9

79-04-9

99-40-1

Anhydrous aluminum trichloride (6.0 g, 45 mmol) was slowly added to the cooled 1,2-dichloroethane (20 mL) solution at 5-10 °C and stirred for 30 min keeping the temperature at 5-10 °C. Subsequently, catechol (1) (2.0 g, 18.1 mmol) was added to the reaction mixture in batches over a period of 10 minutes and stirring was continued for 20 minutes. Chloroacetyl chloride (2.2 g, 19.3 mmol) was added dropwise to the reaction system at the same temperature. The reaction system was then warmed up to room temperature with continuous stirring for 20 hours. Upon completion of the reaction, the reaction was carefully quenched with dilute hydrochloric acid solution (40 mL) at 5-10 °C and stirred at room temperature for 2-3 hours. The solid product was collected by filtration and washed with water. The wet solid was suspended in dilute acetic acid and heated until completely dissolved. Activated charcoal (0.1 g) was added to the clarified solution to decolorize it, stirred for 30 minutes and then hot filtered. The filtrate was cooled to precipitate a solid, filtered, washed with water and dried to give the target product 2-chloro-1-(3,4-dihydroxyphenyl)ethanone (2). Yield: 2.5 g, 74% yield; melting point 175-177 °C.