Potassium Carbonate → 3-(1-tert-butyl-5-chloro-3-trifluoromethyl-1H-pyrazol-4-ylmethylthio)-5,5-dimethyl-2-isoxazoline

Participants

Reaction Steps

21.8 g of sodium hydrosulfide (purity: 70%, 272.5 mmoles) was added to a solution of 24.1 g (136.0 mmoles) of 5,5-dimethyl-3-methylsulfonyl-2-isoxazoline dissolved in 200 ml of N,N-dimethylformamide. The mixture was stirred for 1 hour. Thereto were added 18.8 g (136.2 mmoles) of anhydrous potassium carbonate and 21.0 g (136.2 mmoles) of Rongalit. The resulting mixture was stirred for 2 hours. Thereto was added, with ice-cooling, 40 g (125 mmoles) of 4-bromomethyl-1-tert-butyl-5-chloro-3-trifluoromethyl-1H-pyrazole. The resulting mixture was stirred at room temperature for 2 hours to give rise to a reaction. After the completion of the reaction, the reaction mixture was poured into water, followed by extraction with ethyl acetate. The resulting organic layer was washed with water and an aqueous sodium chloride solution and then dried over anhydrous magnesium sulfate. The resulting solution was subjected to vacuum distillation to remove the solvent contained therein. The residue was purified by silica gel column chromatography (developing solvent: hexane-ethyl acetate mixed solvent) to obtain 23.0 g (yield: 57.1%) of 3-(1-tert-butyl-5-chloro-3-trifluoromethyl-1H-pyrazol-4-ylmethylthio)-5,5-dimethyl-2-isoxazoline as light pink crystals (melting point: 79.0 to 81.0° C.).

Provenance & Evidence