Methyl chloroformate → 4-Methoxycarbonyloxy-3-fluorobenzoic acid

Beteiligte Stoffe

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Reaktionsschritte

4-methoxycarbonyloxy-3-fluorobenzoic acid (VI) was synthesized from 3-fluoro-4-hydroxybenzoic acid (V) by reaction of the latter with methyl chloroformate. NaOH (90 mmol) and 3-fluoro-4-hydroxybenzoic acid (30 mmol) were dissolved in water (80 ml) and cooled to -20° C. Methyl chloroformate (45 mmol) was added dropwise to the mixture. The mixture was then stirred with a magnetic stir bar at 5° C. for four hours and left overnight in the refrigerator. The mixture was then acidified to pH 5 to precipitate 4-methoxycarbonyloxy-3-fluorobenzoic acid. The precipitates were filtered and crystallized from acetonitrile to afford the clean product, 4-methoxycarbonyloxy-3-fluorobenzoic acid (VI), in a 77% yield.

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