Acetylene → 1-(4-Fluorophenoxy)but-3-yn-2-ol

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Reaction Steps

Acetylene gas, dried by passing through a trap containing sulfuric acid, is bubbled at a moderate rate, through 5 ml of vigorously stirred tetrahydrofuran, for 15 minutes. To this acetylenic solution, is then added dropwise, with continued passage of acetylene, 3.5 ml of a 2.4 M solution of n-butylmagnesium chloride in tetrahydrofuran (8.4 mmoles) over 45 minutes. The mixture is stirred a further 15 minutes, and a solution of 580 mg (3.9 mmoles) of p-fluorophenoxy acetaldehyde (Example 156) in 3 ml of tetrahydrofuran is added dropwise over 15 minutes. This solution is stirred for 2 more hours, with passage of acetylene, poured into 50 ml of a saturated solution of ammonium chloride, extracted twice with 50 ml of ether, washed with 10 ml of ammonium chloride solution, dried with magnesium sulfate, filtered, and evaporated. The crude subject product is purified by sublimation at 75° C. (0.1 mm) for 5 hours to give 330 mg (48%) of white crystals, mp 46°-47° C.

Provenance & Evidence