Water → Diethyl 1H-indole-2,6-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

Ethyl 4-(3-ethoxy-2,3-dioxopropyl)-3-nitrobenzoate (91 g, 0.29 mol) is suspended in 800 mL of acetic acid and it is heated with stirring to 75° C. Once the solid is dissolved, water (600 mL) is added. Zinc dust (189 g, 2.9 mol) is added carefully in small portions and the reaction temperature is kept below 85° C. The mixture is then stirred vigorously for 1 hour after the addition. EtOAc (1500 mL) is added and the mixture was filtered through Celite. The solid is washed with more EtOAc (1500 mL) and the filtrates are combined, washed twice with water (1500 mL), four times with saturated NaHCO3 (1000 mL), and once with brine (1000 mL). The filtrate is dried (Na2SO4), filtered, and concentrated to afford the crude compound which was recrystallized from toluene to afford the title compound (44.6 g, 58%) as a yellow powder.

Provenance & Evidence