Cesium carbonate → 4-(6-Nitropyridin-3-yl)-3-oxopiperazine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-bromo-2-nitropyridine (200 mg, 1 mmol), 1-Boc-3-oxopiperazine (240 mg, 1.2 mmol), Xantphos (43 mg, 0.075 mmol), cesium carbonate (326 mg, 1 mmol), palladium(II) acetate (11 mg, 0.049 mmol) in dioxane (5.5 mL) is heated to 120° C. in a Personal Chemistry microwave apparatus for 0.5 h. TLC and LCMS analysis indicates completion of the reaction. The reaction mixture is filtered through Celite, evaporated in vacuo, and the residue is partitioned between water and ethyl acetate. The organic layer is washed with brine, dried (Na2SO4) and evaporated in vacuo. Purification by flash chromatography on silica (ethyl acetate) provides 4-(6-Nitropyridin-3-yl)-3-oxopiperazine-1-carboxylic acid tert-butyl ester as a pale brown solid (248 mg, 77%). MS (ESI) m/z 323 [M+H+].

Provenance & Evidence