Benzyl Bromide → 4-Benzyloxy-5-(4-fluorophenoxy)-1-pentene

Participants

Reaction Steps

A solution of 5-(4-fluorophenoxy)-1-penten-4-ol (9.81 g., 50 mmoles) in dimethylformamide (15 ml.) is added dropwise to a suspension of hexane (2 × 10 ml.) prewashed sodium hydride (50% oil dispersion, 2.64 g., 55mmoles) in dimethylformamide (45 ml.). The resulting mixture is stirred until gas evolution ceases. (A few drops of methanol may be needed to initiate the evolution of hydrogen). The reaction mixture is chilled in an ice bath and treated with a solution of benzyl bromide (10.30 g., 60 mmoles) in dimethylformamide (10 ml.). The reaction mixture is then stirred at room temperature overnight (ca. 16 hours), and then heated on a steam bath for 1 hour. The reaction mixture is diluted with cold water (50 ml.), and extracted with ether four times. The combined extracts are washed with 2N hydrochloric acid and saturated brine and finally dried over anhydrous magnesium sulfate. After the removal of the solvent, the oil residue is vacuum distilled at 112°~6° C./0.025 mm. to give the title compound (13.1 g., 45.7 mmoles, 92%). ir (neat) 3.3~3.5, 6.08, 6.21, 6.65, 8.01, 8.28, 9.13, 10.90, 12.10, 13.18, 13.60, 14.40μ; pmr (CCl4)δ 2.37 (2H, t, J-5Hz), 3.5-4.0 (3H, m), 4.57 (2H, s), 4.8-5.05 (1H, m), 5.05-5.25 (1H, m), 5.4-6.2 (1H, m), 6.6-7.1 (4H, m), 7.19 (5H, s).

Provenance & Evidence