Ethyl Acetate → Methyl 6-fluoro-4-hydroxy-2-naphthoate

Reaktionsgleichung

[F:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[CH:8]=[C:7]([C:12]([OH:14])=[O:13])[CH:6]=[C:5]2[OH:15].S(Cl)(Cl)=O.[C:20](OCC)(=O)C>CO>[CH3:20][O:13][C:12]([C:7]1[CH:6]=[C:5]([OH:15])[C:4]2[C:9](=[CH:10][CH:11]=[C:2]([F:1])[CH:3]=2)[CH:8]=1)=[O:14]

Komponenten

Versuchsvorschrift

To a solution of 6-fluoro-4-hydroxy-naphthalene-2-carboxylic acid (0.500 g, 2.42 mmol) in MeOH (10 mL) was added thionyl chloride (0.265 ml, 3.63 mmol) drop-wise at 0° C. and the resulting mixture was refluxed for 5 hours. Methanol was distilled off under reduced pressure, and the residue was diluted with water (5 mL) and extracted with ethyl acetate (2×10 mL). The combined organic extracts were washed with water (5 mL) followed by brine (5 mL), dried and concentrated under reduced pressure to obtain the crude product. Silica gel column chromatography (5% ethyl acetate in hexanes) afforded 6-fluoro-4-hydroxy-naphthalene-2-carboxylic acid methyl ester (0.150 g, 28%) as a light yellow solid. MS cald. for C12H10FO3 [(M+H)+]: 221, obsd. 221.2.