Cesium carbonate → 4-(3,5-dichlorophenoxy)-3,5-dimethyl-1H-pyrazole

HRID 2215309Notes

Reaction equation

Cl[CH:2]([C:6](=O)[CH3:7])[C:3](=O)[CH3:4].[Cl:9][C:10]1[CH:11]=[C:12]([OH:17])[CH:13]=[C:14]([Cl:16])[CH:15]=1.C(=O)([O-])[O-].[Cs+].[Cs+].O.[NH2:25][NH2:26]>CC(C)=O>[Cl:9][C:10]1[CH:11]=[C:12]([CH:13]=[C:14]([Cl:16])[CH:15]=1)[O:17][C:2]1[C:6]([CH3:7])=[N:25][NH:26][C:3]=1[CH3:4]

Participants

Conditions

Temperature: 60 °C

Procedure

A mixture of 3-chloro-2,4-pentanedione (5.00 g, 37.0 mmol), 3,5-dichlorophenol (6.03 g, 37.0 mmol), cesium carbonate (12.0 g, 37.0 mmol) and acetone (40 ml) was heated under reflux for 18 hours. After cooling the solid was removed by filtration and the filtrate concentrated under reduced pressure. The intermediate was dissolved in ethanol (30 ml) and hydrazine hydrate (1.85 g, 37.0 mmol) was added and the mixture heated at 60° C. for 30 minutes. After cooling the mixture was concentrated under reduced pressure and the residue purified by flash column chromatography on silica gel eluting with ethyl acetate:pentane (30:70, by volume) to provide the title compound (3.00 g) as a yellow oil which solidified on standing to leave a yellow solid, m.p. 85–87° C.

Workup

temperaturewas heated
temperatureunder reflux for 18 hours
temperatureAfter cooling the solid
customwas removed by filtration
concentrationthe filtrate concentrated under reduced pressure
dissolutionThe intermediate was dissolved in ethanol (30 ml)
temperatureAfter cooling the mixture
concentrationwas concentrated under reduced pressure
customthe residue purified by flash column chromatography on silica gel eluting with ethyl acetate:pentane (30:70, by volume)

Sources & evidence

ORD record: ord-30b2c4779f404902baf94d92fa1e5b7d
Source dataset: uspto-grants-2006_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07109228B2

Reaction notes

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