Hydrochloric Acid → 6-(3-(2,4-Difluorophenyl)-1-(pyrrolidin-3-yl)-1H-pyrazol-4-yl)-3-isopropyl-[1,2,4]triazolo[4,3-b]pyridazine

Participants

Reaction Conditions

Reaction Steps

To a round bottom flask was added tert-butyl 3-(3-(2,4-difluorophenyl)-4-(3-isopropyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)-1H-pyrazol-1-yl)pyrrolidine-1-carboxylate and tert-butyl 3-(5-(2,4-difluorophenyl)-4-(3-isopropyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)-1H-pyrazol-1-yl)pyrrolidine-1-carboxylate (0.446 g, 0.875 mmol, Preparation #X.1.1.1) as a mixture of regioisomers followed by 1,4-dioxane (10 mL) and concentrated hydrochloric acid (3.50 mL, 17.5 mmol). The reaction mixture was heated to about 85° C. for about 20 min. The reaction mixture was partitioned between saturated aqueous NaHCO3 and DCM (50 mL). The organic layer was isolated and the aqueous layer extracted with DCM (2×50 mL). The combined organic layers were dried with MgSO4, filtered and concentrated in vacuo. The reaction mixture was purified by flash chromatography (40 g RediSep® silica gel; DCM/MeOH with 5% 2.0 M ammonia in EtOH gradient from 1:0 to 80:20) to give the title compound (0.265 g, 74%): LC/MS (Table 1, Method g) Rt=1.75 min; MS m/z: 410.3 (M+H)+.

Provenance & Evidence