Oxalic acid dihydrate → HCID 178517016, compound

HRID 345412Notes

Reaction equation

HRID 345412 reaction equation
[NH2:1][C:2]1[CH:10]=[CH:9][C:5]2[S:6][CH:7]=[CH:8][C:4]=2[C:3]=1[N+:11]([O-])=O.O.O.[C:16](O)(=[O:20])[C:17](O)=[O:18]>C(O)C.Cl>[OH:18][C:17]1[C:16]([OH:20])=[N:1][C:2]2[CH:10]=[CH:9][C:5]3[S:6][CH:7]=[CH:8][C:4]=3[C:3]=2[N:11]=1

Participants

5

Reactant 2

HCID 61373Oxalic acid dihydrateHCID 19915792HCID 19915792, compound

Product 1

HCID 178517016HCID 178517016, compoundYield 38.8%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolventHCID 702EthanolSolvent

Procedure

A solution of 5-amino-4-nitrobenzo[b]thiophene (0.50 g, 2.6 mmol) in 50 ml of 96% ethanol was hydrogenated at room temperature and atm. pressure in the presence of 5% palladium-on-carbon until the theoretical amount of hydrogen was absorbed. The catalyst was filtered off, and the filtrate was acidified with 1 N hydrochloric acid and evaporated to dryness. The residue was refluxed with oxalic acid dihydrate (0.40 g, 3.1 mmol) in 25 ml of 4M hydrochloric acid for 2 h. The mixture was cooled, and the precipitated solid was isolated by filtration, washed with water, ethanol and ether, and dried. The crude product was dissolved in a minimum amount of 2N sodium hydroxide, treated with decolourising charcoal, and filtered. The filtrate was acidified with 4M hydrochloric acid and the resulting precipitate was collected by filtration, washed with water, ethanol and ether to give 0.22 g (3g%) of the thienoquinoxaline; m.p. 186.6° C.; IR (KBr): 1680 cm-1 ; H-NMR (DMSO-d 6) 7.13 (d,J=9 Hz, 1H, ArH), 7.62 (D,J=9 Hz, 1H, ArH), 7.72 (d,J=5 Hz, 1H, ArH), 7.95 (d,J=5 Hz, 1H, ArH); MS m/z: 218 (M+, 100%).

Workup

  1. customwas hydrogenated at room temperature
  2. custompressure in the presence of 5% palladium-on-carbon until the theoretical amount of hydrogen was absorbed
  3. filtrationThe catalyst was filtered off
  4. customevaporated to dryness
  5. temperatureThe mixture was cooled
  6. customthe precipitated solid was isolated by filtration
  7. washwashed with water, ethanol and ether
  8. customdried
  9. dissolutionThe crude product was dissolved in a minimum amount of 2N sodium hydroxide
  10. additiontreated with decolourising charcoal
  11. filtrationfiltered
  12. filtrationthe resulting precipitate was collected by filtration
  13. washwashed with water, ethanol and ether

Sources & evidence

ORD record
ord-1110b0a9d82246e6848a2047cc2f8db3
Source dataset
uspto-grants-1991_10
Patent number
US05057516

Reaction notes

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