Sulfuric Acid → 2,3,5-Trimethyl-1H-pyrrolo[2,3-d]pyridazin-4(5H)-one

HRID 1291225Notes

Reaction equation

HRID 1291225 reaction equation
[CH3:1][NH:2][NH2:3].C([O:6][C:7]([C:9]1[C:13]([CH3:14])=[C:12]([CH3:15])[NH:11][C:10]=1[CH:16]=O)=O)C.S(=O)(=O)(O)O>C(O)C>[CH3:15][C:12]1[NH:11][C:10]2[CH:16]=[N:3][N:2]([CH3:1])[C:7](=[O:6])[C:9]=2[C:13]=1[CH3:14]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 6061MethylhydrazineHCID 18919237ethyl 2-formyl-4,5-dimethyl-1H-pyrrole-3-carboxylate

Product 1

HCID 1356675992,3,5-Trimethyl-1H-pyrrolo[2,3-d]pyridazin-4(5H)-oneYield 104.2%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of methylhydrazine (1.82 g) and 3-ethoxycarbonyl-4,5-dimethyl-2-formylpyrrole (3.85 g) in ethanol (40 ml) was refluxed for 2 hours. After cooling to room temperature, concentrated sulfuric acid (0.7 ml) was added and the mixture was further refluxed for 13 hours. The mixture was cooled to room temperature and the resulting precipitate was collected by filtration, washed with ethanol and ether, and dried under reduced pressure to provide the title compound as light-yellow powder (3.64 g; yield 100%). 1H-NMR (DMSO-d6) δ: 2.26(6H,s), 3.62(3H,s), 7.98(1H,s), 11.6-11.7(1H,m).

Workup

  1. temperaturethe mixture was further refluxed for 13 hours
  2. temperatureThe mixture was cooled to room temperature
  3. filtrationthe resulting precipitate was collected by filtration
  4. washwashed with ethanol and ether
  5. customdried under reduced pressure

Sources & evidence

ORD record
ord-ff5b76dd6f1d45f79e703caaef075dba
Source dataset
uspto-grants-1998_05
Patent number
US05753664

Reaction notes

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