Dichloromethane → 6-Chloro-4-phenyl-3-(trifluoromethyl)pyridazine

Participants

Reaction Steps

To a stirred solution of 5-phenyl-6-trifluoromethyl-2H-pyridazine-3-one (D2) (20.66 g, 0.086 mol) in acetonitrile (150 ml) was added phosphorous oxychloride (20 ml, 0.215 mmol) and the reaction heated at reflux for 1 h. After this period, the reaction mixture was poured into a saturated solution of sodium hydrogen carbonate, ice and dichloromethane. Further solid sodium hydrogen carbonate was then added until gas evolution had ceased. The organic layer was then separated, dried (Na2SO4) and the solvents evaporated in vacuo. The crude residue was then filtered through silica gel, eluting with dichloromethane, in order to remove the minor isomer. After evaporation of the solvent, the crude product was then re-purified by column chromatography (silica; 0-25% ethyl acetate/heptane) to yield D3 (7.1 g, 32%). C11H6ClF3N2 requires 258; Found 259 (MH+).

Provenance & Evidence