Hydrochloric Acid → 4-chloromethyl-3-methoxy-1-methyl-5-trifluoromethyl-1H-pyrazole

Participants

Reaction Conditions

Reaction Steps

0.45 g of paraformaldehyde (15.0 mmoles in terms of formaldehyde) and 5 ml of concentrated hydrochloric acid were added to a solution of 1.00 g (5.6 mmoles) of 3-methoxy-1-methyl-5-trifluoromethyl-1H-pyrazole dissolved in 25 ml of acetic acid. The mixture was stirred at 80° C. for 2 hours to give rise to a reaction. After the completion of the reaction, the reaction mixture was poured into water and neutralized with potassium carbonate, followed by extraction with ethyl acetate. The resulting organic layer was washed with water 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 0.83 g (yield: 65.0%) of 4-chloromethyl-3-methoxy-1-methyl-5-trifluoromethyl-1H-pyrazole.

Provenance & Evidence