Ethanol → 9H-Indeno[1,2-b]pyrazine-3,9(4H)-dione 9-ethylene acetal

HRID 263899Notes

Reaction equation

HRID 263899 reaction equation
[N:1]1[C:2]2[C:14](=[O:15])[C:13]3[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=3[C:3]=2[NH:4][C:5](=[O:7])[CH:6]=1.C1(C)C=CC(S(O)(=O)=O)=CC=1.O.[CH2:28]([OH:30])[CH3:29]>C(O)CO.C1(C)C=CC=CC=1>[CH2:28]1[O:30][C:5]2([NH:4][C:3]3[C:8]4[CH:9]=[CH:10][CH:11]=[CH:12][C:13]=4[C:14](=[O:15])[C:2]=3[N:1]=[CH:6]2)[O:7][CH2:29]1

Participants

7

Reactant 4

HCID 702EthanolHCID 962WaterHCID 6101p-Toluenesulfonic acidHCID 190359769H-Indeno[1,2-b]pyrazine-3,9(4H)-dione

Product 1

HCID 677228069H-Indeno[1,2-b]pyrazine-3,9(4H)-dione 9-ethylene acetalYield 83%

Reagents, catalysts & solvents 2

HCID 174Ethylene GlycolSolventHCID 1140TolueneSolvent

Procedure

A suspension of 9H-indeno[1,2-b]pyrazine-3,9(4H)-dione (1.0 g, 5.05 mmol) in ethylene glycol (10 ml), toluene (20 ml) and p-toluenesulfonic acid (20 mg) was refluxed with water separation for 18 hours. The reaction mixture was cooled to room temperature, ethanol (5 ml) was added and the precipitate was filtered off and washed with ethanol and dried to give 1.014 g (83%) of the title compound. M.p. 296°-298° C. 1H-NMR (DMSO-d6, δ): 4.3-4.42 (m, 4H), 7.43-7.6 (m, 3H), 7.75 (d, 1H), 7.88 (s, 1H), 12.7 (s, 1H).

Workup

  1. filtrationthe precipitate was filtered off
  2. washwashed with ethanol
  3. customdried

Sources & evidence

ORD record
ord-ae1bdbc6166546a2946401fab85c4974
Source dataset
uspto-grants-1997_07
Patent number
US05646146

Reaction notes

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