Tributylvinyltin → 2-Amino-4-trifluoromethyl-5-vinyl-benzoic acid methyl ester

Participants

Reaction Steps

Add tetrakis palladium(triphenylphosphine)(0) (5.00 g, 4.33 mmol) to a mixture of 2-amino-5-iodo-4-trifluoromethyl-benzoic acid methyl ester (Example 3, Step 3) (17.25 g, 49.99 mmol) and tributyl(vinyl)tin (16.10 mL, 55.14 mmol) in toluene (500 mL) and heat at reflux for 14 h. Allow the reaction to cool to room temperature dilute the mixture with ethyl acetate (1 L). Wash the mixture with saturated aqueous potassium fluoride solution (3×300 mL), then water (300 mL), followed by brine (500 mL). Dry the organic layer over anhydrous sodium sulfate, filter, and remove the solvents under reduced pressure. Purify the residue by column chromatography on silica gel, eluting with ethyl acetate/hexanes (0 to 15%), to provide the title compound as a pale yellow solid (8.73 g, 71%): TLC Rf 0.52 (3:1 hexanes/ethyl acetate); 1H NMR (CDCl3, 300 MHz) δ 3.89 (s, 3H), 5.21-5.30 (m, 1H), 5.60-5.71 (m, 1H), 5.98 (bs, 2H), 6.83-7.02 (m, 2H), 8.19 (s, 1H).

Provenance & Evidence