Acetyl chloride → 6-[4-[4-[2-(4-Acetylpiperazin-1-yl)ethoxy]phenyl]piperidin-1-yl]-3-(trifluoromethyl)[1,2,4]triazolo[4,3-b]pyridazine

Participants

Reaction Conditions

Reaction Steps

A solution of acetyl chloride (0.029 mL, 0.40 mmol) in DCM (0.5 mL) was added dropwise to 6-[4-[4-(2-piperazin-1-ylethoxy)phenyl]piperidin-1-yl]-3-(trifluoromethyl)[1,2,4]triazolo[4,3-b]pyridazine (obtained as described in Example 727) (160 mg, 0.34 mmol) and triethylamine (0.094 mL, 0.67 mmol) in DCM (1 mL) cooled to 0° C. under nitrogen. The resulting solution was stirred at 0° C. for 5 minutes then allowed to warm to room temperature and stirred for 15 minutes. The reaction mixture was diluted with water (2 mL), passed through a phase separating cartridge and the organic layer evaporated to afford crude product. The crude product was purified by preparative HPLC (Waters XBridge Prep C18 OBD column, 5μ silica, 19 mm diameter, 100 mm length), using decreasingly polar mixtures of water (containing 1% ammonia) and MeCN as eluents. Fractions containing the desired compound were evaporated to dryness to afford 6-[4-[4-[2-(4-acetylpiperazin-1-yl)ethoxy]phenyl]piperidin-1-yl]-3-(trifluoromethyl)[1,2,4]triazolo[4,3-b]pyridazine (60.0 mg, 35%).

Provenance & Evidence