5-Bromo-3-methylisothiazole → 6-(1-(6-(3-Methylisothiazol-5-yl)-[1,2,4]triazolo[4,3-b]pyridazin-3-yl)ethyl)quinoline

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-bromo-3-methylisothiazole (1.00 g, 5.6 mmol) in 10 mL of THF at −45° C. (CH3CN/dry ice) was added isopropylmagnesium chloride LiCl complex (7.9 ml, 7.9 mmol) (LiCl complex, 1M in THF). The mixture was stirred at −45° C. for 20 minutes and was added zinc chloride, 0.5 m in thf (17 ml, 8.4 mmol) slowly via a syringe. The mixture was then warmed up to rt and continued to stir for additional 30 minutes. 6-(1-(6-chloro-[1,2,4]triazolo[4,3-b]pyridazin-3-yl)ethyl)quinoline (0.5787 g, 1.9 mmol), tris(dibenzylideneacetone)dipalladium (o) (0.51 g, 0.56 mmol) and Q-Phos (0.65 g) in 15 mL of N,N-dimethyl acetamide was added to the reaction mixture. The reaction was warmed up to 50° C. for 6 h and was quenched with 50 mL of satd. NH4Cl aq. solution. The mixture was extracted with 150 mL of EtOAc and the organic phase was washed with 60 mL of brine. The aqueous phases were extracted with 100 mL EtOAc again. The combined organic phases were dried over Na2SO4 and concentrated in vacuo. The residue was purified by a silica gel column chromatography (EtOAc to 15% MeOH in EtOAc) to give red solid as desired product 6-(1-(6-(3-methylisothiazol-5-yl)-[1,2,4]triazolo[4,3-b]pyridazin-3-yl)ethyl)quinoline. MS (ESI, pos. ion) m/z: 373.2 (M+1).

Provenance & Evidence