Diisopropylethylamine → 6-(6,6-Difluorohexahydro-1H-1,4-diazepin-1-yl)-3-(trifluoromethyl)-1,2,4-triazolo[4,3-b]pyridazine

Participants

Reaction Conditions

Reaction Steps

A mixture of 6-chloro-3-(trifluoromethyl)-[1,2,4]triazolo[4,3-b]pyridazine (1 g, 4.49 mmol), tert-butyl 6,6-difluoro-1,4-diazepane-1-carboxylate (1.06 g, 4.49 mmol) and DIPEA (1.56 ml, 8.99 mmol) in DMA (15 mL) was stirred at 135° C. for 6 hours. The reaction mixture was concentrated to dryness and DCM (30 mL) was added. The solution was cooled in an ice bath and TFA (15 mL) was added. The resulting mixture was stirred at room temperature for 4 hours. The reaction mixture was concentrated to dryness, diluted with water, basified with 6M aqueous sodium hydroxide and extracted with DCM. The organic phase was washed with water and brine, dried over magnesium sulfate and concentrated. The residue was purified by flash chromatography on silica gel eluting with 0 to 4% methanol in DCM to give 6-(6,6-difluoro-1,4-diazepan-1-yl)-3-(trifluoromethyl)-[1,2,4]triazolo[4,3-b]pyridazine (0.820 g, 56.6%) as a beige solid.

Provenance & Evidence