Tributylvinyltin → 3-Methyl-4-vinylbenzofuran-2-carboxylic acid ethyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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.

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