Sodium ethoxide → 2-(Bromomethyl)-5-fluoro-2,3-dihydrobenzofuran

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Reaction Steps

A sodium ethoxide solution, prepared in the conventional manner starting from 15.2 parts of sodium in 100 parts of ethanol, is added dropwise to a mixture of 231 parts of 3-(2,3-dibromopropyl)-4-acetoxy-fluorobenzene in 800 parts of ethanol (exothermic reaction: temperature rises to 50° C.). Upon completion, stirring is continued for 2 hours at reflux temperature. The reaction mixture is cooled to room temperature, filtered from some insoluble matter and the filtrate is evaporated. The residue is divided between water and ether. The aqueous layer is separated and extracted once more with ether. The combined ethereal phases are dried over calcium chloride, filtered and evaporated. The oily residue is distilled in vacuo, yielding 102 parts of 2-bromomethyl-2,3-dihydro-5-fluorobenzofuran; bp. 100° -105° C. at 1.5 mm. pressure.

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