Sodium Acetate → 4-Acetoxy-6-fluoro-3-methyl-naphthalene-2-carboxylic acid methyl ester

Beteiligte Stoffe

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Reaktionsschritte

To a solution of crude 2-(4-fluoro-benzylidene)-3-methyl-succinic acid 1-methyl ester (approximately 49 g, 0.196 mol) in acetic anhydride (490 mL) was added sodium acetate (32.15 g, 0.392 mol) in one portion. The reaction mixture was stirred at 150° C. for 3 hours. After this time, the reaction mixture was cooled to room temperature, then stirred overnight. Acetic anhydride was removed in vacuo, providing a viscous brown oil. This crude product was dissolved in ethyl acetate. The resulting solution was washed with a saturated, aqueous ammonium chloride solution. The organic phase was dried over Na2SO4, filtered, and concentrated. Flash chromatography (Analogix SuperFlash™ 10% ethyl acetate in hexane) gave 18.4 g (34%) of 4-acetoxy-6-fluoro-3-methyl-naphthalene-2-carboxylic acid methyl ester as a yellow oil.

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