Dibutyl Vinylboronate (stabilized with Phenothiazine) → 2-Hydroxy-4-vinyl-benzoic acid methyl ester

Beteiligte Stoffe

Reaktionsschritte

A solution of 2-hydroxy-4-iodo-benzoic acid methyl ester (8.01 g, 0.0288 mol) in THF (184 ml) and H2O (46 ml) is treated with vinyl-boronic acid di-butyl ester (9.53 ml, 0.0432 mol, 1.5 eq.), NaCO3 (21.37 g, 0.201 mol, 7 eq.), and dichloro-bis(triphenyl-phosphine)palladium (1.01 g, 1.44 mmol, 5 mol %). The solution is purged with N2 (g) for 5 minutes and then heated to reflux for 2 hour. The reaction is concentrated in vacuo, diluted with EtOAc, and sequentially washed with H2O and saturated aqueous NaCl. The organic phase is dried over MgSO4, filtered, and concentrated. The crude product is purified with silica gel column chromatography (5% ethyl acetate in hexanes) to afford 2-hydroxy-4-vinyl-benzoic acid methyl ester: ESMS m/z 179.1 (M+H+).

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