Cesium carbonate → 4-Isopropenyl-2-methyl-benzoic acid methyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

4-Bromo-2-methyl-benzoic acid methyl ester (4 g, 17.46 mmol), isopropenylboronic acid pinacol ester (3.228 g, 19.21 mmol) and cesium carbonate (19.913 g, 61.11 mmol) were treated with a degassed solution of 15 ml dioxane/5 ml water. After 5 min stirring [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) complex (0.718 g, 0.873 mmol) was added and heated to 120° C. for 40 min in the microwave. The reaction mixture was filtered over cellulose; washed with 20 ml dioxane and concentrated in vacuo. The residue was purified by 120 g silica gel chromatography (gradient elution 0-50% ethyl acetate in hexane during 50 min) to yield 4-Isopropenyl-2-methyl-benzoic acid methyl ester (2.94 g, 15.45 mmol). MS (ESI) 191.3 (M+H)+

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