반응 #351082

반응 방정식

9H-indeno[1,2-b]pyrazine-3,9(4H)-dione

p-toluenesulfonic acid

water

→

title compound

수율 78.5%

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

수율 78.5%

용매

toluene

2,3-butanediol

반응 조건

후처리

1. 1
   기타The reaction mixture was evaporated in vacuo to dryness
2. 2
   workup.ADDITIONanother portion of toluene, 2,3-butanediol and p-toluenesulfonic acid was added
3. 3
   온도the mixture was refluxed again for 20 hours
4. 4
   기타After evaporation to dryness
5. 5
   여과the precipitate was filtered off
6. 6
   세척washed with ethanol
7. 7
   기타dried

실험 절차

A suspension of 9H-indeno[1,2-b]pyrazine-3,9(4H)-dione (2.0 g, 10.09 mmol) in toluene (50 ml), 2,3-butanediol (20 ml) and p-toluenesulfonic acid (40 mg) was refluxed with water separation for 20 hours. The reaction mixture was evaporated in vacuo to dryness and another portion of toluene, 2,3-butanediol and p-toluenesulfonic acid was added and the mixture was refluxed again for 20 hours. After evaporation to dryness, the residue was suspended in ethanol (10 ml) and the precipitate was filtered off and washed with ethanol and dried to give 2.14 g (78.5%) of the title compound as a mixture of isomers. 1H-NMR (DMSO-d6, δ): 1.24-1.4 (m, 6H), 4.03-4.87 (m, 2H), 7.42-7.91 (m, 5H), 12.6 (s, 1H).

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