Cesium carbonate → 2,3-dichloro-N-[4-(6-chloro-5-cyano-pyrazin-2-yl)-phenyl]-benzenesulfonamide

Participants

Reaction Conditions

Reaction Steps

2,3-Dichloro-N-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl]-benzenesulfonamide (5.78 g) was added to a reaction vessel containing a magnetic stirring bar together with 3,5-dichloro-pyrazine-2-carbonitrile (2.35 g), 1,1′-bis(diphenylphosphino)ferrocene-palladium(II) dichloride (Pd(dppf)2Cl2) (791 mg) and cesium carbonate (13.2 g), followed by 100 ml dioxane and 10 ml water, and the mixture heated to 100° C. under stirring. After 3 h the reaction mixture was cooled to RT and quenched with a saturated aqueous sodium bicarbonate solution (100 ml) and extracted with EtOAc (3×200 ml). The combined aqueous phases were dried over sodium sulfate, filtered and evaporated to afford the crude product as a brown oil. Purification by flash chromatography on silica gel using a mixture of EtOAc and heptane as the eluent afforded 2,3-dichloro-N-[4-(6-chloro-5-cyano-pyrazin-2yl)-phenyl]-benzenesulfonamide as a light brown foam after evaporation of the solvents under reduced pressure. Yield: 4.32 g (73%).

Provenance & Evidence