Dichloromethane → 8-(3-Pyridinyl)-7-octyn-1-ol

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Reaction Steps

A flame-dried, 22-L flask equipped with a mechanical stirrer, condenser, and a gas inlet tube dipping below the surface of the solvent was charged with 4.0 L of methylene chloride, 1.25 L of triethylamine, 385 g of 7-octyn-1-ol, and 285 mL (456 g) of 3-bromopyridine. The reagents were rinsed into the flask with an additional 100 mL of methylene chloride. Argon was bubbled through the reaction mixture for 30 minutes. The flask was evacuated for 3 minutes at 70 mm. The vacuum was released by bubbling in argon. This process was repeated six times and then 42 g of dichlorobis(triphenyl phosphine)palladium (II) and 4 g of cuprous iodide were added. The mixture was heated at a gentle reflux for 18 hours and cooled to 20°. To the mixture was added, with vigorous stirring, 8.0 L of ether. A small amount of yellowish-white solid was removed by filtration and washed with 2×1.5 L=3.0 L of ether. The combined filtrate was washed with 3.0 L of deionized water and 2×3.0 L=6.0 L of 1N hydrochloric acid. The combined aqueous solutions were washed with 2×2.5 L=5.0 L of ether. The organic solutions were discarded and the aqueous solution was made strongly basic by the addition of 2.50 L of 20% sodium hydroxide solution. The resulting mixture was extracted with 3×4.0 L=12.0 L of methylene chloride. The extracts were dried over sodium sulfate and filtered through Celite. Solvent removal on a rotary evaporator at 45° gave 534.2 g (91% yield) of a pale brown 8-(3-pyridinyl)-7-octyn-1-ol having a strong odor of 3-bromopyridine. No further purification of this material was undertaken.

Provenance & Evidence