Water → 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic Acid

Participants

Reaction Conditions

Reaction Steps

To a solution of 6,7-dichloro-2,3-dihydro-2-hydroxymethylbenzofuran (10.4 gm.) in acetone (200 ml.) cooled to 20° C. is added an oxidizing solution prepared from chromium trioxide (6.0 g.), concentrated sulfuric acid (5.3 ml.) and water (43 ml.) over a one-half hour period. The reaction mixture is stirred at 25° C. for 18 hours. The acetone layer is separated from the precipitated chromium salts, added to water (600 ml.) and extracted with ether (2 × 150 ml.). The ether extract is washed with water then extracted with aqueous sodium bicarbonate. Acidification of the basic solution gives 3.4 g. of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid.

Provenance & Evidence