Water → HCID 178516995, compound

HRID 1461327Notes

Reaction equation

HRID 1461327 reaction equation
[NH2:1][C:2]1[C:11]([NH2:12])=[CH:10][CH:9]=[C:8]2[C:3]=1[N:4]=[C:5]([OH:14])[C:6]([OH:13])=[N:7]2.O.[CH:16]([CH:18]=O)=O.C(=O)([O-])[O-].[Na+].[Na+]>[OH-].[Na+]>[OH:14][C:5]1[C:6]([OH:13])=[N:7][C:8]2[C:3]([N:4]=1)=[C:2]1[C:11](=[CH:10][CH:9]=2)[N:12]=[CH:18][CH:16]=[N:1]1

Participants

6

Reactant 4

HCID 962WaterHCID 7860GlyoxalHCID 10340Sodium CarbonateHCID 178507339HCID 178507339, compound

Product 1

HCID 178516995HCID 178516995, compoundYield 36%

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Conditions

Temperature
50 °C

Procedure

A mixture of 0,5 g (2,6 mmol) 5,6-diamino-2,3-dihydroxyquinoxaline and 20 ml water was added 0,6 ml (3,9 mmol) 40% aqueous glyoxal and 0,41 g (3,9 mmol) sodium carbonate. The reaction mixture was stirred at 50° C. for 1,5 h. After cooling to 25° C., the precipitate was filtered off and washed with water to give 0,49 g. The crude product was dissolved in 2N sodium hydroxide and reprecipitated with 2N hydrochloric acid to pH 6-7 to give 0,2 g (36%) 2,3-dihydroxypyrazino(2,3-f)quinoxaline, m.p.>300° C. NMR (DMSO-d6): 8.30 (1H,d), 8.20 (1H,d), 7.27 (1H,d), 7.0 (1H,d).

Workup

  1. temperatureAfter cooling to 25° C.
  2. filtrationthe precipitate was filtered off
  3. washwashed with water
  4. customto give 0,49 g
  5. customreprecipitated with 2N hydrochloric acid to pH 6-7

Sources & evidence

ORD record
ord-e729e026b0a44c88b38061020fab8976
Source dataset
uspto-grants-1991_12
Patent number
US05075306

Reaction notes

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