N-bromobutanimide → 1-(2,4-Difluorophenyl)-2-(3-isopropyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)ethane-1,2-dione

Participants

Reaction Steps

To a round bottom flask was added 1-(2,4-difluorophenyl)-2-(3-isopropyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)ethanone (1.50 g, 4.74 mmol, Preparation #K.1) followed by DMSO (15 mL) and NBS (0.844 g, 4.74 mmol). The reaction mixture was stirred at about ambient temperature for about 3 d. The reaction mixture was partitioned between EtOAc and water. The layers were separated, and the organic layer was washed with brine, dried over MgSO4, filtered, and concentrated in vacuo. The crude material was purified by silica gel chromatography using heptane/EtOAc (gradient, 1:0 to 0:1) to give the title compound (1.14 g, 73%): LC/MS (Table 1, Method a) Rt=2.4 min; MS m/z: 331.1 (M+H)+.

Provenance & Evidence