Cesium carbonate → (4-Chloro-3-fluoro-phenyl)-propynoic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

To a mixture of 4-chloro-3-fluoroiodobenzene (74.27 g, 284 mmol) and cesium carbonate (185.0 g, 568 mmol) in tetrahydrofuran (730 mL) was added under an argon atmosphere cuprous iodide (2.16 g, 11.4 mmol) and bis(triphenylphosphine)palladium (II) chloride (3.98 g, 5.7 mmol). Ethyl propiolate (57.0 g, 575 mmol) was added dropwise over a period of 20 min. The resulting dark brown suspension was stirred for 38 h at 35° C., then filtrated over Hyflo® and the residue was washed with tetrahydrofuran (285 ml). The filtrate was evaporated and purification of the residue by chromatography (SiO2, heptane: ethyl acetate=90:10) afforded the title compound (57.1 g, 89%) as a yellow liquid. MS m/e: 226.0 [M]+.

Provenance & Evidence