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

HRID 129444Notes

Reaction equation

HRID 129444 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-23822854a35043a397407781165306f2
Source dataset
uspto-grants-1995_11
Patent number
US05468748

Reaction notes

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