Oxalic acid dihydrate → 6-Chloro-1-methylquinoxaline-2,3(1H,4H)-dione

HRID 1709213Notes

Reaction equation

HRID 1709213 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([NH:8][CH3:9])=[C:4]([N+:10]([O-])=O)[CH:3]=1.O.O.[C:15]([OH:20])(=O)[C:16](O)=[O:17]>C(O)C.Cl>[Cl:1][C:2]1[CH:3]=[C:4]2[C:5](=[CH:6][CH:7]=1)[N:8]([CH3:9])[C:16](=[O:17])[C:15](=[O:20])[NH:10]2

Participants

5

Reactant 2

HCID 61373Oxalic acid dihydrateHCID 27368364-chloro-N-methyl-2-nitroaniline

Product 1

HCID 32931736-Chloro-1-methylquinoxaline-2,3(1H,4H)-dioneYield 23%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolventHCID 702EthanolSolvent

Procedure

A suspension of 4-chloro-1-methylamino-2-nitrobenzene (1.73 g, 9.3 mmol) in 50 ml of ethanol was hydrogenated at room temperature and 2 atm. pressure in the presence of 5% palladium-on-carbon (0.5 g) until the theoretical amount of hydrogen was absorbed. The catalyst was filtered off, and 50 ml of IN hydrochloric acid was added to the filtrate. The acidic filtrate was evaporated to dryness and the solid residue was refluxed with oxalic acid dihydrate (1.4 g, 11 mmol) in 100 ml of 4M hydrochloric acid for 90 min. The mixture was cooled and the precipitated product was collected by filtration and washed with water, ethanol and ether to give 0.45 g (23%) of the title compound. M.p. 341.5° C. (N,N-dimethylformamide); IR (KBr): 1700, 1660 cm-1, 1H-NMR (DMSO-d6 : 3.43 (s, 3H, CH3), 6.97-7.40 (m, 3H, ArH), 12.0 (broad s, 1H, NH); MS m/z: 212 (M+ +2, 50%), 210 (M+, 100%).

Workup

  1. customwas hydrogenated at room temperature
  2. custom2 atm. pressure in the presence of 5% palladium-on-carbon (0.5 g) until the theoretical amount of hydrogen was absorbed
  3. filtrationThe catalyst was filtered off
  4. addition50 ml of IN hydrochloric acid was added to the filtrate
  5. customThe acidic filtrate was evaporated to dryness
  6. temperatureThe mixture was cooled
  7. filtrationthe precipitated product was collected by filtration
  8. washwashed with water, ethanol and ether

Sources & evidence

ORD record
ord-13bd3ee29e14429297436e0fe7022926
Source dataset
uspto-grants-1990_08
Patent number
US04948794

Reaction notes

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