Resorcinol → 4-(chloromethyl)-7-hydroxy-2H-chromen-2-one

Participants

Reaction Steps

Ethyl 4-chloroacetoacetate (10.0 mL, 73.0 mmol) was added dropwise to a cold (ice bath) solution of resorcinol (8.0 g, 73.0 mmol) in concentrated H2SO4 (100 mL). The cooling bath was removed, and the reaction mixture was stirred at room temperature overnight (15 h), then poured onto ice (500 mL) and stirred until all ice had melted. The precipitate was collected by filtration and washed with water (200 mL). The solid was dissolved in hot EtOH:ligroin (4:1, 100 mL), filtered, and the filtrate was kept in the freezer (−20° C.) for 3 h. The solid was collected by filtration, washed with ligroin (3×10 mL), and dried to give 4-Chloromethyl-7-hydroxy-2H-chromen-2-one (1) as a pale white solid (12.2 g, 79%).

Provenance & Evidence