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

HRID 507073Notes

Reaction equation

HRID 507073 reaction equation
ON=[CH:3][C:4]([NH:6][C:7]1[CH:8]=[C:9]2[C:13](=[CH:14][CH:15]=1)[CH2:12][CH2:11][CH2:10]2)=[O:5].S(=O)(=O)(O)[OH:17]>>[NH:6]1[C:7]2[C:15](=[CH:14][C:13]3[CH2:12][CH2:11][CH2:10][C:9]=3[CH:8]=2)[C:3](=[O:17])[C:4]1=[O:5]

Participants

3

Conditions

Temperature
80 °C

Procedure

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).

Workup

  1. temperatureCool to room temperature
  2. filtrationfilter the precipitate
  3. dissolutionDissolve the solid in warmed ethanol
  4. customleave
  5. temperatureto cool overnight
  6. filtrationFilter the precipitate
  7. washwash with ethyl ether
  8. customDry the solid

Sources & evidence

ORD record
ord-0b5f2ce785d6412ca4a0ab37ed05dafd
Source dataset
uspto-grants-2010_08
Patent number
US07786108B2

Reaction notes

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