2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → HCID 21106351, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 7-iodo-5-nitro-2,3-dihydro-1H-indole II (15 g, 51.7 mmol) in ethanol (1200 mL) and isopropanol (20 mL) at 25° C. was treated with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (13.6 g, 59.9 mmol). The resulting solution was warmed to 65° C. and air was bubbled through for 1 h. An additional 0.57 equivalents of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (6.8 g, 29.9 mmol) was added and the reaction was stirred at 65° C. for another 2 h before being concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230–400 mesh, 90/10 toluene/ethyl acetate) afforded 7-iodo-5-nitro-1H-indole III (13.07 g, 79%) as a yellow solid: 1H NMR (DMSO-d6, 300 MHz) δ 11.82 (broad s, 1H), 8.59 (d, J=1.83 Hz, 1H), 8.30 (d, J=1.83 Hz, 1H), 7.61 (t, J=2.93 Hz, 1H), 6.90 (dd, J1=1.83 Hz, J2=3.30 Hz, 1H).

Provenance & Evidence