Potassium Carbonate → 5-(3,5-dichlorophenylsulfanyl)-4-formyl-1-isopropyl-1H-pyrazole-3-carboxylic acid ethyl ester

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Reaction Conditions

Reaction Steps

A solution containing 6 g of 5-chloro-4-formyl-1-isopropyl-1H-pyrazole-3-carboxylic acid ethyl ester in 10 ml of anhydrous dimethyl formamide was treated at room temperature with 5.28 g of 3,5-dichlorothiophenol and 4.07 g of potassium carbonate. The mixture was then heated at 60° C. for 1 h before being left to cool to room temperature. The solvent removed under reduced pressure and the residue partitioned between dichloromethane and water. The organic extract was washed with brine then dried over anhydrous magnesium sulphate, filtered and evaporated. The residue was purified by flash chromatography on silica gel using diethyl ether/petoleum ether (1:4 to 1:3) for the elution to give 8.53 g of 5-(3,5-dichlorophenylthio)-4-formyl-1-isopropyl-1H-pyrazole-3-carboxylic acid ethyl ester as a yellow oil. Mass spectrum (ESI) m/z [M+H]+.

Provenance & Evidence