2-(2-Chlorobenzyloxy)-5-fluorobenzoic acid → 2-(2-Chlorobenzyloxy)-5-fluorobenzyl alcohol

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Reaction Steps

5.50 g (20 mmol) of 2-(2-chlorobenzyloxy)-5-fluorobenzoic acid are dissolved in 25 ml of THF, heated to reflux and then 20 ml of 1 M borane-dimethyl sulfide complex are added dropwise. The reaction solution is then cooled to room temperature and stirred at this temperature for 1 h. The solvent is distilled out in vacuo, and water is added to the residue. Acidification is then carried out cautiously (copious gas evolution) with 1 N hydrochloric acid. 1 N sodium hydroxide solution is then added to make slightly basic, and the aqueous phase is extracted three times with dichloromethane. The organic phases are dried over magnesium sulfate, filtered and washed with dichloromethane, and the filtrate is concentrated. Petroleum ether is added to the residue, and the crystals which have separated out are filtered off with suction and dried on a clay dish. 3.65 g (13.6 mmol, 68% of theory) of the title compound are isolated.

Provenance & Evidence