Triethylamine → 6-(1-Dodecynyl)-2-pyridinecarboxaldehyde

Participants

Reaction Conditions

Reaction Steps

To a solution of 6-bromo-2-pyridinecarboxaldehyde (3.0 g) in tetrahydrofuran (10 ml), was added sequentially bis(triphenylphosphine)palladium(II)chloride (0.178 g), copper(I)iodide (0.024 g), 1-dodecyne (3.25 ml), and triethylamine (2.12 ml). The solution was stirred at 40° C. overnight. The reaction mixture was cooled to room temperature, charged again with bis(triphenylphosphine)palladium (II) chloride (0.024 g), copper (1) iodide (0.024 g), and triethylamine (2.12 ml), and 1-dodecyne (3.25 ml), and tetrahydrofuran (5.0 ml), and heated at 40° C. for 5 hrs. The reaction mixture was again cooled and recharged as above, and heated at 40° C. for 24 hrs. The cooled mixture was concentrated, taken up in ethyl acetate (100 ml), washed with water and saturated sodium chloride solution, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated. The residue was taken up in ethyl acetate (100 ml) and filtered. The filtrate was combined with material from a similar reaction run 1.43 g of the carboxaldehyde and proportionate amounts of the catalysts, 1-dodecyne, and solvent. The filtrate was concentrated. The residue was purified by flash chromatography using 1.5% ethyl acetate/hexane followed by 1% ethyl acetate/hexane as eluents. The appropriate fractions were collected and concentrated to yield 2.24 g (29%) of product, as an oil.

Provenance & Evidence