Cesium carbonate → 3-(4-Bromo-thiophen-2-yl)-oxazolidin-2-one

Participants

Reaction Conditions

Reaction Steps

N,N-Dimethylethylamine (0.22 mL, 2.0 mmol), 2,4-dibromothiophene (5.0 g, 20.6 mmol) and oxazolidinone (2.1 g, 24.8 mmol) were added to a mixture of copper(I) iodide (0.39 g, 2.0 mmol) and cesium carbonate (13.4 g, 41.3 mmol) in dry dioxane under nitrogen. The reaction mixture was stirred at 110° C. for 16 h. The reaction was filtered through the Celite™ reagent and rinsed with methylene chloride. The filtrate was concentrated in vacuo to a residue. Purification of the crude product on silica gel using a stepwise gradient of 6:1 to 3:1 hexane:ethyl acetate as the eluent gave 3-(4-bromo-thiophen-2-yl)-oxazolidin-2-one (790 mg, 15%) as the desired product contaminated with 10% of the 3-(5-bromo-thiophen-3-yl)-oxazolidin-2-one isomer. MS (ES) m/z 249 [M+H]+.

Provenance & Evidence