Carbon tetrabromide → 4-bromomethyl-5-(3,5-dichlorophenylthio)-1-isopropyl-1H-pyrazole-3-carboxylic acid ethyl ester

Participants

Reaction Steps

To a solution of 504 mg 5-(3,5-dichlorophenylthio)-4-hydroxymethyl-1-isopropyl-1H-pyrazole-3-carboxylic acid ethyl ester in 5 ml of dichloromethane was added 375 mg of triphenylphosphine and 474 mg of carbon tetrabromide. The reaction mixture was stirred overnight. The solvent was removed and the residue was purified by flash chromatography on silica gel using diethyl ether/iso-hexane for the elution to give 367 mg of 4-bromomethyl-5-(3,5-dichlorophenylthio)-1-isopropyl-1H-pyrazole-3-carboxylic acid ethyl ester as a colourless gum. Mass spectrum (ES) m/z 451 [M+H]+.

Provenance & Evidence