Cesium carbonate → Methyl 3-(6-Chloro-2-methyl-3-oxo-2,3-dihydropyridazin-4-ylamino)-1-methyl-1H-pyrazole-5-carboxylate

Participants

Reaction Conditions

Reaction Steps

In a 3-neck RBF was placed 119a (500 mg, 3.2 mmol), 4-bromo-6-chloro-2-methylpyridazin-3(2H)-one (725 mg, 3.2 mmol), cesium carbonate (2.3 g, 7.0 mmol), and Xantphos (160 mg, 8.5 mol %). The flask was evacuated and filled with nitrogen 3×. Dioxane (20 ml) was added and the mixture degassed for 25 min with bubbling nitrogen. Tris(dibenzylideneacetone)dipalladium(0) (150 mg, 5 mol %) was then added and the reaction heated to 100° C. for 6 hrs. The reaction was cooled and diluted with EtOAc (125 mL) and saturated aqueous NaHCO3 (50 mL), the layers were separated and extracted EtOAc (2×100 mL). The organics were washed with brine 3×, dried over Na2SO4, filtered, and concentrated under reduced pressure. The residue was purified by chromatography: ISCO 40 g silica, EtOAc/hexanes, to give 119b.

Provenance & Evidence