2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → Ethyl 5-bromo-1H-indole-7-carboxylate

Participants

Reaction Steps

DDQ (119.3 g. 525.7 mmol) was added in several portions to a solution of ethyl 5-bromo-2,3-dihydro-1H-indole-7-carboxylate (129.1 g, 0.48 mmol) in CHCl3 (1500 mL) and the mixture was stirred for 2 h. The reaction was filtered and the solid was washed with CHCl3 (3×500 mL). The filtrate was washed with 5% NaOH (3×500 mL), H2O (500 mL) and brine (500 mL) then dried over Na2SO4. The solution was evaporated and the residue was recrystallized with EtOH, giving 88 g (69%) of the title compound.

Provenance & Evidence