反応 #42400

反応方程式

methyl 3-bromo-5-(hydroxymethyl)benzoate

cesium carbonate

potassium carbonate

trimethyl boroxine

→

title compound

Methyl 3-(hydroxymethyl)-5-methylbenzoate

溶媒

dioxane

反応条件

後処理

1. 1
   温度The reaction mixture is refluxed for 12 h
2. 2
   その他partitioned between water and ethyl acetate
3. 3
   洗浄The organic layer is washed with water and brine
4. 4
   乾燥dried (magnesium sulfate)
5. 5
   ろ過filtered
6. 6
   濃縮concentrated under reduced pressure
7. 7
   その他followed by purification by flash column chromatography (silica, 25% ethyl acetate/hexanes)

実験手順

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).

出典