Phosphorus tribromide → 4-bromomethyl-1-tert-butyl-5-chloro-3-trifluoromethyl-1H-pyrazole

Participants

Reaction Conditions

Reaction Steps

A solution of 9.2 g (35.7 mmoles) of (1-tert-butyl-5-chloro-3-trifluoromethyl-1H-pyrazol-4-yl)-methanol dissolved in 100 ml of diethyl ether was cooled to −10° C. Thereto was added 11.6 g (42.9 mmoles) of phosphorus tribromide. The mixture was stirred at room temperature overnight to give rise to a reaction. After the completion of the reaction, the reaction mixture was poured into ice water and extraction with diethyl ether was conducted. The resulting organic layer was washed with an aqueous sodium chloride solution and then dried over anhydrous magnesium sulfate. The resulting solution was subjected to reduced pressure distillation to remove the solvent contained therein, to obtain 10.0 g (yield: 87.3%) of 4-bromomethyl-1-tert-butyl-5-chloro-3-trifluoromethyl-1H-pyra-zole.

Provenance & Evidence