Sulfuric Acid → Methyl 8-bromo-4,5-dihydro-4-oxo-1-(tetrahydro-2H-pyran-4-yl)[1,2,4]triazolo[4,3-a]quinoxaline-7-carboxylate

HRID 1807866Notes

Reaction equation

HRID 1807866 reaction equation
[Br:1][C:2]1[CH:11]=[C:10]2[C:5]([NH:6][C:7](=[O:21])[C:8]3[N:9]2[C:12]([CH:15]2[CH2:20][CH2:19][O:18][CH2:17][CH2:16]2)=[N:13][N:14]=3)=[CH:4][C:3]=1[C:22]([OH:24])=[O:23].S(=O)(=O)(O)O.[C:30](=O)([O-])O.[Na+]>CO>[Br:1][C:2]1[CH:11]=[C:10]2[C:5]([NH:6][C:7](=[O:21])[C:8]3[N:9]2[C:12]([CH:15]2[CH2:20][CH2:19][O:18][CH2:17][CH2:16]2)=[N:13][N:14]=3)=[CH:4][C:3]=1[C:22]([O:24][CH3:30])=[O:23]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 516892Sodium BicarbonateHCID 58575207HCID 58575207, compound

Product 1

HCID 58575443Methyl 8-bromo-4,5-dihydro-4-oxo-1-(tetrahydro-2H-pyran-4-yl)[1,2,4]triazolo[4,3-a]quinoxaline-7-carboxylate

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a mixed liquid of 360 mg of 8-bromo-4-oxo-1-(tetrahydro-2H-pyran-4-yl)-4,5-dihydro[1,2,4]triazolo[4,3-a]quinoxaline-7-carboxylic acid and 10 mL of methanol was added 2 mL of concentrated sulfuric acid, followed by stirring overnight under a refluxing condition. After cooling to room temperature, the pH was adjusted to about 8 by the addition of a saturated aqueous sodium hydrogen carbonate solution, followed by extraction with a mixed liquid of chloroform and isopropanol. The organic layer was washed with saturated brine and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure to obtain 320 mg of methyl 8-bromo-4-oxo-1-(tetrahydro-2H-pyran-4-yl)-4,5-dihydro[1,2,4]triazolo[4,3-a]quinoxaline-7-carboxylate as an orange solid.

Workup

  1. extractionfollowed by extraction with a mixed liquid of chloroform and isopropanol
  2. washThe organic layer was washed with saturated brine
  3. dry with materialdried over anhydrous magnesium sulfate
  4. customThe solvent was evaporated under reduced pressure

Sources & evidence

ORD record
ord-d21422c3663541138ce267582ed3ed77
Source dataset
uspto-grants-2013_01
Patent number
US08357688B2

Reaction notes

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