Acetic Acid → 1H-2-Benzopyran-3-carboxylic acid, 4-(4-fluorophenyl)-1-oxo-

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Reaction Steps

A stirred mixture of 3,3-bis(ethoxycarbonyl)-4-(4-fluorophenyl)-4-hydroxy-3,4-dihydroisocoumarin (3.85 g), glacial acetic acid (40 ml) and concentrated hydrochloric acid (40 ml) was heated at reflux for 2 hours. The mixture was then cooled and poured onto a mixture of ice and water (200 ml), and the resulting solid was filtered off and washed with water, to give 4-(4-fluorophenyl)isocoumarin-3-carboxylic acid (2.65 g) in the form of a white powder, m.p.218°-220° C. [Elemental analysis: C,67.4; H,3.41; F,6.73%; calculated: C,67.6; H,3.19; F,6.68%].

Provenance & Evidence