Water → Methyl 6-quinoxalinecarboxylate

HRID 252847Notes

Reaction equation

HRID 252847 reaction equation
[CH3:1][O:2][C:3](=[O:12])[C:4]1[CH:9]=[CH:8][C:7]([NH2:10])=[C:6]([NH2:11])[CH:5]=1.[CH:13]([CH:15]=O)=O.O>C(O)(C)C>[N:10]1[C:7]2[C:6](=[CH:5][C:4]([C:3]([O:2][CH3:1])=[O:12])=[CH:9][CH:8]=2)[N:11]=[CH:15][CH:13]=1

Participants

5

Reactant 3

HCID 962WaterHCID 7860GlyoxalHCID 1355243,5-Diamino-2-methylbenzoic acid

Product 1

HCID 2781239Methyl 6-quinoxalinecarboxylateYield 93%

Reagents, catalysts & solvents 1

HCID 3776IsopropanolSolvent

Conditions

Temperature
80 °C

Procedure

To a stirred solution of 3,4-diamino-benzoic acid methyl ester (236, 2 g, 12.03 mmol) in isopropanol (50 mL) was added oxaldehyde as a 40% solution in water (13.23 mmol, 1.52 mL). The reaction mixture was heated at 80° C. for 2 hours, the solvent was removed under reduced pressure and the residue was dried under vacuum to yield 237a as a yellow solid (2.09 g, 93% yield). 1H NMR: (DMSO) δ 9.01 (s, 2H), 8.54 (d, J=1.6 Hz, 1H), 8.23 (dd, J=8.6, 2.0 Hz, 1H), 8.14 (dd, J=8.6, 0.6 Hz, 1H), 3.35 (s, 3H).

Workup

  1. customthe solvent was removed under reduced pressure
  2. customthe residue was dried under vacuum

Sources & evidence

ORD record
ord-92196afd2d9848e78673ee2addf86140
Source dataset
uspto-grants-2011_01
Patent number
US07868205B2

Reaction notes

Loading…