Thionyl Chloride → 2-(4-nitrophenyl)-1,2-dihydro-3H-pyrazolo[4,3-c]cinnolin-3-one

HRID 1875476Notes

Reaction equation

HRID 1875476 reaction equation
S(Cl)(Cl)=O.O[C:6]1[C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[N:9]=[N:8][C:7]=1[C:16]([O:18]C)=O.[N+:20]([C:23]1[CH:28]=[CH:27][C:26]([NH:29][NH2:30])=[CH:25][CH:24]=1)([O-:22])=[O:21]>C(O)C>[N+:20]([C:23]1[CH:24]=[CH:25][C:26]([N:29]2[C:16](=[O:18])[C:7]3[N:8]=[N:9][C:10]4[CH:11]=[CH:12][CH:13]=[CH:14][C:15]=4[C:6]=3[NH:30]2)=[CH:27][CH:28]=1)([O-:22])=[O:21]

Participants

5

Reactant 3

HCID 24386Thionyl ChlorideHCID 3310889(4-Nitrophenyl)hydrazineHCID 178499158HCID 178499158, compound

Product 1

HCID 589748402-(4-nitrophenyl)-1,2-dihydro-3H-pyrazolo[4,3-c]cinnolin-3-one

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Thionyl chloride (326 g, 200 ml) was added dropwise under inert atmosphere to methyl 4-hydroxycinnoline-3-carboxylate (10.0 g, 49 mmol). The mixture was heated to reflux for 2.5 h, cooled to room temperature and excess thionyl chloride was removed under vacuum. Toluene (100 ml) was added to the residue and removed under vacuum. This procedure was repeated with further toluene (100 ml). A brown semi-solid material was obtained and taken up in ethanol (200 ml). 4-Nitrophenylhydrazine (5.99 g, 39.2 mmol) was added portionwise. The mixture was stirred at room temperature overnight. The mixture was heated to 40-45° C. for 1 h and cooled to room temperature. The solids were collected by filtration, triturated with ethanol (100 ml) and dried under vacuum. The title compound was isolated as a brown solid (8.42 g, 27.4 mmol, 70%). LCMS: m/z 308 [M+H]+.

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux for 2.5 h
  3. customexcess thionyl chloride was removed under vacuum
  4. additionToluene (100 ml) was added to the residue
  5. customremoved under vacuum
  6. customA brown semi-solid material was obtained
  7. temperatureThe mixture was heated to 40-45° C. for 1 h
  8. temperaturecooled to room temperature
  9. filtrationThe solids were collected by filtration
  10. customtriturated with ethanol (100 ml)
  11. customdried under vacuum

Sources & evidence

ORD record
ord-ef28e5fff4174daba87dd409dd588f53
Source dataset
uspto-grants-2012_11
Patent number
US08309552B2

Reaction notes

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