Tetrahydrofuran → Ethyl 4-ethynylbenzoate

Participants

Reaction Steps

A solution of ethyl 4-iodobenzoate (6.9 g, 25 mmol), (trimethylsilyl)acetylene (7.1 mL, 50 mmol) and triethylamine (200 mL) was purged with argon for 10 minutes, and then treated with bis(triphenylphosphine)palladium (II) chloride (175 mg, 0.25 mmol) and copper (I) iodide (48 mg, 0.25 mmol). The suspension was stirred at room temperature for 3 hours and concentrated under the vacuum of a water aspirator. The residue was dissolved in hexane and washed with 10% aqueous HCl. The layers were separated and the aqueous layer was extracted twice with hexane. The combined organic fractions were washed with water, and brine. The separated organic layer was treated directly with 1 M solution of tetrabutylammonium fluoride and THF (35 mL, 35 mmol). After 30 minutes, the solution was washed with water (2×), and brine, dried (MgSO4) and filtered through silica gel. The solvents were removed under reduced pressure and the residue was purified by silica gel chromatography (98:2, hexane:ethyl acetate) to give the title compound as a yellow oil.

Provenance & Evidence