Cesium carbonate → HCID 69359925, Verbindung

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A flask was charged under nitrogen with 3-bromo-5-iodo-benzoic acid methyl ester (D8b) (840 mg, 2.2 mmol, 1.1 equiv), Cs2CO3 (900 mg, 2.8 mmol, 1.4 equiv), tris(dibenzylideneacetone)dipalladium(0) (92 mg, 0.1 mmol, 0.05 equiv), Xantphos (120 mg, 0.2 mmol, 0.1 equiv) and toluene (40 ml). 5-Phenyl-2-piperidinone (Koelsch, J. Am. Chem. Soc. 1943, (65), 2093, 350 mg, 2 mmol, 1 equiv) was then added and the resulting mixture was stirred at 100° C. for 2.5 h then cooled to room temperature and concentrated in vacuo. The residue was partitioned between AcOEt and a saturated aqueous NaHCO3 solution. The layers were separated and the organic phase was dried over MgSO4 and concentrated in vacuo to give a solid residue. Purification of the residue by flash chromatography on silica gel (iso-hexane/AcOEt: 4/1 to 1/1) gave 1,1-dimethylethyl 3-bromo-5-(2-oxo-5-phenyl-1-piperidinyl)benzoate (D191) (480 mg, 51%) as a white solid. [M+H]+=432.2, RT=3.82 min.

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