Propyne → (3-Prop-1-ynylpyridin-4-yl)carbamic acid tert-butyl ester

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Reaction Steps

Propyne (6.3 mL, 124 mmol) was condensed in a pressure tube at −78° C. A solution of (3-iodopyridin-4-yl)carbamic acid tert-butyl ester (7.98 g, 24.9 mmol) in 15 mL of DMF, 60 mL of triethylamine, dichlorobis(triphenylphosphine)palladium (II) (877 mg, 1.25 mmol), and CuI (472 mg, 2.49 mmol) were added, and the tube was sealed and stirred at room temperature overnight. 200 mL of ethyl acetate and 100 mL of saturated aqueous ammonium chloride solution were added, the phases were separated and the aqueous layer was extracted with three 100 mL portions of ethyl acetate. The combined organic layers were dried over magnesium sulfate, filtered, and concentrated in vacuo. Chromatography on SiO2 (25% to 40% ethyl acetate in hexanes, gradient) afforded 5.65 g of (3-prop-1-ynylpyridin-4-yl)carbamic acid tert-butyl ester (98% yield).

Provenance & Evidence