Reacción #42400

Ecuación de reacción

methyl 3-bromo-5-(hydroxymethyl)benzoate

cesium carbonate

potassium carbonate

trimethyl boroxine

→

title compound

Methyl 3-(hydroxymethyl)-5-methylbenzoate

Disolventes

dioxane

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe reaction mixture is refluxed for 12 h
2. 2
   Otropartitioned between water and ethyl acetate
3. 3
   LavadoThe organic layer is washed with water and brine
4. 4
   Secadodried (magnesium sulfate)
5. 5
   Filtraciónfiltered
6. 6
   Concentraciónconcentrated under reduced pressure
7. 7
   Otrofollowed by purification by flash column chromatography (silica, 25% ethyl acetate/hexanes)

Procedimiento

To a stirred solution of methyl 3-bromo-5-(hydroxymethyl)benzoate (4.53 g, 18.5 mmol) in dioxane (74 mL) is added cesium carbonate (6.0 g, 18.5 mmol), potassium carbonate (5.1 g, 37 mmol), and palladium(0)tetrakis(triphenylphosphine) (2.1 g, 1.85 mmol), followed by trimethyl boroxine (5.1 mL, 37 mmol). The reaction mixture is refluxed for 12 h, cooled to room temperature, and then partitioned between water and ethyl acetate. The organic layer is washed with water and brine, dried (magnesium sulfate), filtered, and concentrated under reduced pressure. The black oil is adsorbed onto silica gel followed by purification by flash column chromatography (silica, 25% ethyl acetate/hexanes) to provide the title compound. 1H NMR (300 MHz, CDCl3) δ 7.75 (s, 1H), 7.65 (s, 1H), 7.39 (s, 1H), 5.31 (br s, 1H), 4.53 (s, 1H), 3.84 (s, 3H), 2.36 (s, 3H).

Fuente