5-amino-3H-pyrazol-3-one → 7-(2,3-Dichlorophenyl)-1,2,4,7-tetrahydro-5-methyl-2-oxopyrazolo[1,5-a]pyrimidine-6-carboxylic acid, ethyl ester

HRID 1252989Notes

Reaction equation

HRID 1252989 reaction equation
[Cl:1][C:2]1[C:7]([Cl:8])=[CH:6][CH:5]=[CH:4][C:3]=1[CH:9]=[C:10]([C:16](=O)[CH3:17])[C:11]([O:13][CH2:14][CH3:15])=[O:12].[NH2:19][C:20]1[N:21]=[N:22][C:23](=[O:25])[CH:24]=1>CN(C)C=O.C(OCC)(=O)C>[Cl:1][C:2]1[C:7]([Cl:8])=[CH:6][CH:5]=[CH:4][C:3]=1[CH:9]1[N:21]2[NH:22][C:23](=[O:25])[CH:24]=[C:20]2[NH:19][C:16]([CH3:17])=[C:10]1[C:11]([O:13][CH2:14][CH3:15])=[O:12]

Participants

5

Reactant 2

HCID 42555565-amino-3H-pyrazol-3-oneHCID 54112468Ethyl 2-[(2,3-dichlorophenyl)methylidene]-3-oxobutanoate

Product 1

HCID 141304317-(2,3-Dichlorophenyl)-1,2,4,7-tetrahydro-5-methyl-2-oxopyrazolo[1,5-a]pyrimidine-6-carboxylic acid, ethyl esterYield 38.6%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Procedure

A solution of 2-[(2,3-dichlorophenyl)methylene]-3-oxobutanoic acid, ethyl ester (2.8 g; 10.0 mmole) in dimethylformamide (7 ml) was treated with 3-amino-5-pyrazolone (990 mg) and the resulting mixture was heated at 65° C.±5° for 15 hours. The reaction mixture was allowed to cool to room temperature and then diluted with ethyl acetate. The solution was washed with water, brine, and dried over anhydrous magnesium sulfate. Evaporation of the solvent provided a foam which was purified by flash chromatography (7% methanol in dichloromethane). The product was crystallized from acetonitrile-isopropyl ether to provide the title compound as a solid (1.42 g; melting point 213°-218° C.; sinters above 155° C.).

Workup

  1. temperaturethe resulting mixture was heated at 65° C.±5° for 15 hours
  2. washThe solution was washed with water, brine
  3. dry with materialdried over anhydrous magnesium sulfate
  4. customEvaporation of the solvent
  5. customprovided a foam which
  6. customwas purified by flash chromatography (7% methanol in dichloromethane)
  7. customThe product was crystallized from acetonitrile-isopropyl ether

Sources & evidence

ORD record
ord-f78e2d7279a34a54a79cf6d7d830d5ac
Source dataset
uspto-grants-1988_05
Patent number
US04746656

Reaction notes

Loading…