Cesium carbonate → 6-chloro-4-(1,5-dimethyl-1H-pyrazol-3-ylamino)-2-methylpyridazin-3(2H)-one

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Reaction Conditions

Reaction Steps

1,5-Dimethyl-1H-pyrazol-3-amine (400 mg, 3.6 mmol, Eq: 1.00) and 4-bromo-6-chloro-2-methylpyridazin-3(2H)-one (965 mg, 4.32 mmol, Eq: 1.20) were combined with 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (312 mg, 540 μmol, Eq: 0.15), cesium carbonate (3.52 g, 10.8 mmol, Eq: 3) and tris(dibenzylideneacetone)dipalladium(0) (165 mg, 180 μmol, Eq: 0.05) in dioxane (10.0 ml). The solution was degassed with Ar. The reaction mixture heated at 100° C. for 18 h. The mixture was cooled to room temperature. The solution was diluted with 100 ml DCM. The organic layer was washed with water. The organic layer was dried over MgSO4. Concentrated in vacuo. The crude material was purified by flash chromatography (silica gel, 40 g, 10% to 50% (60:10:1 DCM:MeOH:NH4OH)/DCM gradient) to give 6-chloro-4-(1,5-dimethyl-1H-pyrazol-3-ylamino)-2-methylpyridazin-3(2H)-one (408 mg, 45%). LC/MS-ESI observed [M+H]+ 235.

Provenance & Evidence