Cesium carbonate → HCID 67355976, compound

Participants

Reaction Conditions

Reaction Steps

To a degassed mixture of 4-(piperazin-1-yl)-benzoic acid ethyl ester (1.45 g, 6.2 mmol), 4-bromobenzoic acid tert-butyl ester (1.75 g, 6.8 mmol), cesium carbonate (3.9 g, 12 mmol) in dioxane (25 mL) was added tris(dibenzylideneacetone)dipalladium (300 mg, 5 mol %) and 2-(dicyclohexylphosphino)-2′,4′,6′-tris(isopropyl)-biphenyl (x-phos, 300 mg, 10 mol %). The mixture was heated in a sealed tube with stirring at 100° C. for 3 hrs. Solvents were evaporated and the residue was extracted with ethyl acetate and water, The organic layer was dried over sodium sulfate and solvents were evaporated. The crude material was purified through a flash column chromatography using ethyl acetate and hexanes to give the intermediate 4-[4-(4-ethoxycarbonylphenyl)-piperazin-1-yl]-benzoic acid tert-butyl ester as solid (1.3 g, 51% yield)

Provenance & Evidence