Cesium carbonate → 1,1-Dimethylethyl 4-[(4-nitro-2-pyridinyl)oxy]-1-piperidinecarboxylate

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Reaction Steps

Add 100 mL of toluene to a nitrogen purged mixture of 2-chloro-4-nitro-pyridine (4.32 g, 27.2 mmol), tert-butyl 4-hydroxypiperidine carboxylate (11.0 g, 54.5 mmol), cesium carbonate (13.3 g, 40.8 mmol), palladium acetate (122 mg, 0.544 mmol) and 2-(di-tert-butylphosphino)-1,1′-binapthyl (271 mg, 0.68 mmol). Stir the resulting mixture overnight at room temperature, then partition between water and ethyl acetate. Extract the aqueous layer with additional ethyl acetate, and dry the combined organic layer over sodium sulfate and concentrate under reduced pressure. Subject residue to silica gel chromatography eluting with a gradient of 0 to 20% ethyl acetate in hexanes to afford 4-(4-nitro-pyridin-2-yloxy)-piperidine-1-carboxylic acid tert-butyl ester as a white waxy solid (5.37 g, 61%; LCMS ES+(m/z) 268 [M-tBu]+).

Provenance & Evidence