6-Chloro-3-(trifluoromethyl)-(1,2,4)triazolo(4,3-b)pyridazine → 6-[4-(5-Bromopyridin-2-yl)piperazin-1-yl]-3-(trifluoromethyl)-[1,2,4]triazolo[4,3-b]pyridazine

A mixture of 1-(5-bromopyridin-2-yl)piperazine and 6-chloro-3-(trifluoromethyl)-[1,2,4]triazolo[4,3-b]pyridazine in ethanol (7 mL) was stirred at 80° C. for 20 hours. The reaction mixture was concentrated and partitioned between dichloromethane (50 mL) and saturated aqueous sodium bicarbonate solution (25 mL). The aqueous phase was extracted twice with dichloromethane (2×50 mL). The organic phases were combined, washed with water (100 mL), and concentrated to give a residue that was purified by flash chromatography on silica-gel using ethyl acetate as eluant to give 6-[4-(5-bromopyridin-2-yl)piperazin-1-yl]-3-(trifluoromethyl)-[1,2,4]triazolo[4,3-b]pyridazine 0.353 g, 73.4%)

1. concentrationThe reaction mixture was concentrated
2. custompartitioned between dichloromethane (50 mL) and saturated aqueous sodium bicarbonate solution (25 mL)
3. extractionThe aqueous phase was extracted twice with dichloromethane (2×50 mL)
4. washwashed with water (100 mL)
5. concentrationconcentrated
6. customto give a residue that
7. customwas purified by flash chromatography on silica-gel

ORD record

ord-d6860edd11ed4533ba150f0c21bbc8e4

Source dataset

uspto-grants-2011_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08003649B2