反応 #57598

反応方程式

3-methyl-4-trifluoromethanesulfonyloxy-benzofuran-2-carboxylic acid ethyl ester

vinyl tributyltin

lithium chloride

→

3-methyl-4-vinylbenzofuran-2-carboxylic acid ethyl ester

収率 75.2%

溶媒

DMF

water

反応条件

後処理

1. 1
   温度cooled to room temperature
2. 2
   抽出extracted with ether
3. 3
   洗浄The combined organics were washed with water and brine
4. 4
   乾燥dried over magnesium sulfate
5. 5
   ろ過filtered
6. 6
   濃縮concentrated in vacuo
7. 7
   その他The residue was chromatographed on silica gel eluting with ethyl acetate/hexanes (1:25)

実験手順

To a solution of 2.48 g (7.05 mmol) of 3-methyl-4-trifluoromethanesulfonyloxy-benzofuran-2-carboxylic acid ethyl ester (Example 20, Step 2) in 30 mL of DMF was added 2.16 mL (7.40 mmol) of vinyl tributyltin, 0.898 g (21.1 mmol) of lithium chloride and 0.247 g (0.352 mmol) of tetrakis(triphenylphosphine)palladium(0). The reaction was heated to 90° C. for 3 h and then cooled to room temperature. The reaction was diluted with water and extracted with ether. The combined organics were washed with water and brine, dried over magnesium sulfate, filtered and concentrated in vacuo. The residue was chromatographed on silica gel eluting with ethyl acetate/hexanes (1:25) to provide 1.22 g of 3-methyl-4-vinylbenzofuran-2-carboxylic acid ethyl ester.

出典