Phosphorus oxychloride → 3-Chloro-6-(2-chlorophenyl)-7-(4-chlorophenyl)-[1,2,4]triazolo[4,3-b]pyridazine

Participants

Reaction Conditions

Reaction Steps

A suspension of 6-(2-chlorophenyl)-7-(4-chlorophenyl)-[1,2,4]triazolo[4,3-b]pyridazin-3(2H)-one (1.0 g, 2.8 mmol) in phosphorus oxychloride (10 mL) was stirred at 130° C. for 6 h. Analysis by HPLC/MS indicated the starting material had been consumed. After cooling to room temperature, the reaction mixture was concentrated under reduced pressure. The obtained residue was diluted with CH2Cl2, the resulting solution washed with saturated aqueous NaHCO3, saturated aqueous NaCl, dried (Na2SO4) and concentrated under reduced pressure to afford 1.1 g (100%) of the title compound as an off-white solid. HPLC/MS (method A): retention time=3.52 min, (M+H)+=375.0.

Provenance & Evidence