Phosphorus oxychloride → 2-Chloro-4-[1-sec-butyl-3-(5-chloro-2-thienyl)-1H-pyrazol-4-yl]pyridine

Participants

Reaction Steps

4-[1-sec-butyl-3-(5-chloro-2-thienyl)-1H-pyrazol-4-yl]pyridine-N-oxide (6.1 mmol) was stirred in 20 mL of phosphorous oxychloride at 120° C. for 5 h. The solvent was then evaporated and the residue was treated with methanol and evaporated again. The residue was purified by chromatography on silica gel (hepthane:ethyl acetate 5:1 to 3:1) to afford 623 mg of 2-Chloro-4-[1-sec-butyl-3-(5-chloro-2-thienyl)-1H-pyrazol-4-yl]pyridine (29% yield).

Provenance & Evidence