Hydrochloric Acid → 2-Fluoro-6-(1-methyleneethyl)anisole

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

41.8 g (639 mmol) of zinc dust and 874 mg (3.1 mmol) of lead(II) chloride are suspended in 557 ml of THF and at room temperature 39 ml (556 mmol) of dibromomethane are added. The mixture is stirred for a further 30 minutes and at 0° C. 68.8 ml (68.8 mmol) of a 1 M titanium(IV) chloride solution in dichloromethane are added dropwise. The cooling bath is removed and after 30 minutes at room temperature 13.6 g (80.8 mmol) of 1-(3-fluoro-2-methoxyphenyl)ethan-1-one (Chem. Commun. 2000, 14, 1323-4) in 139 ml of THF are added dropwise. The reaction mixture is stirred for a further 1.5 hours at room temperature. It is diluted with diethyl ether and cautiously poured onto a mixture of 4 M hydrochloric acid and ice. The phases are separated and subjected to extraction with diethyl ether, the extracts are washed with water and dried over sodium sulphate and the solvent is removed. The crude product is purified by column chromatography on silica gel (hexane/isopropyl ether 0-5%) to give 9.5 g of 2-fluoro-6-(1-methyleneethyl)anisole.

Herkunft & Nachweise