Tributylvinyltin → 1-(3-Chloro-5-vinyl-2-pyridyl)cyclopropanecarbonitrile

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Reaction Steps

4.7 g of 1-(5-Bromo-3-chloro-pyridin-2-yl)-cyclopropanecarbonitrile (step 2 of PREPARATION EXAMPLE 3) was dissolved in 40 ml anhydrous toluene, then 700 mg of tetrakis(triphenylphosphine)palladium(0) and 9.0 g vinyltributylstannane were added under a nitrogen atmosphere. The reaction mixture was heated on reflux for 3 hours. After cooling to ambient temperature, the reaction mixture was filtered, the filtrate was diluted with 100 ml of ethyl acetate, then washed with water and with saturated potassium fluoride solution. The organic layer was dried over anhydrous sodium sulfate and concentrated. Crude material was obtained as a dark oil, which was purified by flash chromatography on silica gel with heptane/ethyl acetate as a solvent. Thus, 1.9 g of 1-(3-chloro-5-vinyl-2-pyridyl)cyclopropanecarbonitrile was obtained as a yellow oil. 1H-NMR (CDCl3): 8.40 ppm (s, 1H), 7.78 ppm (s, 1H), 6.67 ppm (dd, 1H), 5.87 ppm (d, 1H), 5.50 ppm (d, 1H), 1.77 ppm (m, 2H), 1.63 ppm (m, 2H).

Provenance & Evidence