Ethyl Acetate → 4-Methyl-2-[4-(trifluoromethyl)phenyl]-2H-1,2,3-triazole 1-oxide

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of anti-pyruvic aldehyde 1-oxime (2.67 g, 30.7 mmol) in diethyl ether (50 mL) was added 4-(trifluoromethyl)phenylhydrazine (5.40 g, 30.7 mmol). The reaction mixture was stirred at 23° C. for 2 h, then concentrated under reduced pressure. The crude residue was dissolved in 15% aqueous pyridine (150 mL). A solution of copper(II) sulfate pentahydrate (15.31 g, 61.3 mmol) in water (75 mL) was added at once. The resulting mixture was stirred at reflux for 17 h, then cooled to 0° C. Ethyl acetate (100 mL) was added and the mixture was filtered through Celite® diatomaceaous filter aid. The layers were separated, and the aqueous layer was extracted with ethyl acetate (2×100 mL). The combined organic layers were washed with 1.0 M aqueous hydrochloric acid (3×50 mL). The organic layer was dried (MgSO4), filtered, and evaporated under reduced pressure. The residue was purified by chromatography on silica gel, eluting with 0 to 50% ethyl acetate in hexanes, to afford the title compound (5.84 g) as a colorless solid.

Provenance & Evidence