Sulfuric Acid → Cyclopent[f]indole-2,3-dione, 1,5,6,7-tetrahydro-

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Reaction Conditions

Reaction Steps

Add 2-hydroxyimino-N-indan-5-yl-acetamide (4.66 g, 22.84 mmol) in small portions at 65° C. to concentrated sulfuric acid (22 mL) and heat the mixture at 80° C. for 15 minutes. Cool to room temperature, pour into ice water (200 mL) and filter the precipitate. Dissolve the solid in warmed ethanol and leave to cool overnight. Filter the precipitate and wash with ethyl ether. Dry the solid to yield the title compound (3.3 g, 77%). 1H NMR (dimethyl sulfoxide-d6, 300 MHz) δ 1.98 (quintuplet, J=7.7 Hz, 2H), 2.76 (t, J=7.7 Hz, 2H), 2.85 (t, J=7.7 Hz, 2H), 6.74 (s, 1H), 7.28 (s, 1H). MS (ES−): 186 (M−H).

Provenance & Evidence