Tributylvinyltin → HCID 69417337, compound

Participants

Reaction Steps

A solution of 5-Fluoro-6-(2-fluoro-4-iodo-phenylamino)-3-methyl-3H-benzoimidazole-5-carboxylic acid methyl ester (6.36 g, 14.4 mmol) and vinyl tributylstannane (5.0 g, 15.8 mmol) in dioxane (100 mL) was de-gassed by freeze-pump-thaw cycle (twice). Tetrakis(triphenylphoshine)palladium was added and the reaction mixture was refluxed under an atmosphere of nitrogen until mass spectrometry indicated complete consumption of the aryl iodide. The reaction mixture was allowed to cool to ambient temperature and was filtered through a pad of Celite and washed with ethyl acetate (255 mL). Aqueous potassium fluoride (1M, 50 mL) was added to the filtrate and the biphasic mixture was shaken. The resultant precipitate was removed by filtration and the organics were further washed with aqueous potassium fluoride (1M, 50 mL), water (2×100 mL), and saturated brine (100 mL). The solution was dried over anhydrous sodium sulfate, concentrated in vacuo and chromatographed on silica gel. Elution with ethyl acetate afforded 5-Fluoro-6-(2-fluoro-4-vinyl-phenylamino)-3-methyl-3H-benzoimidazole-5-carboxylic acid methyl ester (2.13 g, 44% yield): 1H NMR (400 MHz, DMSO-d6) δ 8.44 (s, 1 H), 8.09 (br s, 1 H), 8.06 (s, 1 H), 5.36 (dd, J=13.2, 1.5 Hz, 1 H), 5.05 (dd, J=8.3, 1.5 Hz, 1 H), 6.60 (dd, J=15.5, 10.9 Hz, 1 H), 6.50 (td, J=8.8, 4.6 Hz, 1 H), 5.65 (d, J=15.4 Hz, 1 H), 5.11 (d, J=11.2 Hz, 1 H), 3.92 (s, 3 H), 3.82 (s, 3 H).

Provenance & Evidence