Hydrochloric Acid → Methyl 3-(4-fluoro-2-hydroxyphenyl)-3-oxopropanoate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A 1.0 M tetrahydrofuran solution of lithium bis(trimethylsilyl)amide (39.0 mL, 39.0 mmol) was stirred at −78° C. and treated over a 25 min period with a solution of 1-(4-fluoro-2-hydroxyphenyl)ethanone (2.00 g, 13.0 mmol) in 50 mL of tetrahydrofuran. The resulting solution was stirred at −78° C. for 1 h, and then at −15° C. for 2 h. After being cooled again to −78° C., the solution was treated with a solution of dimethyl carbonate (1.20 mL, 14.3 mmol) in tetrahydrofuran (5 mL). The resulting mixture was allowed to warm to rt where it stirred overnight. After this time, the mixture was poured over ice and then concentrated hydrochloric acid (10 mL) was added. The resulting mixture was extracted three times with dichloromethane. The combined organic phases were washed twice with water, dried over sodium sulfate and then concentrated under vacuum to yield a residue. The residue was purified by radial thin-layer chromatography (silica gel, 2-40% ethyl acetate-hexane) to provide methyl 3-(4-fluoro-2-hydroxyphenyl)-3-oxopropanoate as a white solid (1.76 g, 64%). 1H NMR (400 MHz, CDCl3) δ ppm 3.78 (s, 3 H) 3.98 (s, 2 H) 6.62-6.71 (m, 2 H) 7.69 (dd, J=8.9, 6.4 Hz, 1 H) 12.15 (d, J=1.5 Hz, 1 H). Mass spectrum m/z 213.14 (M+H)+.

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