Triethylamine → 6-[4-(4-{2-[4-(Methylsulfonyl)piperazin-1-yl]ethoxy}phenyl)piperidin-1-yl]-3-(trifluoromethyl)-7,8-dihydro[1,2,4]triazolo[4,3-b]pyridazine

Participants

Reaction Conditions

Reaction Steps

A solution of methanesulfonyl chloride (0.029 mL, 0.38 mmol) in DCM (0.5 mL) was is added dropwise to 6-[4-[4-[2-(piperazin-1-yl)ethoxy]phenyl]piperidin-1-yl]-3-(trifluoromethyl)-7,8-dihydro-[1,2,4]triazolo[4,3-b]pyridazine (obtained as described in Example 5.1, preparation of starting materials) (150 mg, 0.31 mmol) and triethylamine (0.088 mL, 0.63 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 a further 15 minutes. The reaction mixture was diluted with water (2 mL), passed through a phase separating cartridge and then the organic layer was 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-(methylsulfonyl)piperazin-1-yl]ethoxy}phenyl)piperidin-1-yl]-3-(trifluoromethyl)-7,8-dihydro[1,2,4]triazolo[4,3-b]pyridazine (92 mg, 52.7%) as a solid.

Provenance & Evidence