Tetrahydrofuran → 3-Ethynyl-4-fluorophthalonitrile

Participants

Reaction Steps

To a solution of 4-fluoro-3-((trimethylsilyl)ethynyl)phthalonitrile (Example 40C) (0.302 g, 1.246 mmol) in anhyd THF (5 mL) was added a solution of TBAF in THF (1.246 mL, 1.246 mmol), dropwise. The resulting black mixture was stirred at rt under N2 for 5 min. The mixture was poured into water and extracted with EtOAc (×3). Combined organics were washed (water, brine), dried over Na2SO4 and concentrated in vacuo. The residue was purified by low pressure liquid chromatography (silica gel, EtOAc/hexanes, gradient elution) affording 3-ethynyl-4-fluorophthalonitrile (0.0635 g, 30% yield) as a tan solid: 1H NMR (400 MHz, CDCl3) δ 7.79 (dd, J=8.7, 4.7 Hz, 1H), 7.49 (dd, J=8.7, 8.0 Hz, 1H), 3.86 (s, 1H); MS (GCMS EI) m/z 170 ([M]+, 100%).

Provenance & Evidence