Diethyl Ether → (1-Ethyl-7-methoxy-2-oxo-1,2-dihydro-quinolin-3-yl)-acetic acid methyl ester

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Reaction Steps

A slurry of (7-methoxy-2-oxo-1,2-dihydro-quinolin-3-yl)-acetic acid methyl ester (5.0 g, 20 mmol) in tetrahydrofuran (40 mL) was treated with potassium bis(trimethylsilyl)amide (0.5 M in toluene, 41 mL, 21 mmol) at 25° C. and the mixture heated to reflux. After 1 h at reflux, ethyl iodide (16 mL, 200 mmol) was added. After an additional 3 h at reflux, the cooled mixture was quenched with 0.1N aqueous HCl (50 mL) and concentrated in vacuo. Water (200 mL) was added and the aqueous phase extracted with chloroform (3×200 mL). The extracts were dried (K2CO3) and concentrated in vacuo to give the crude product (5.3 g). Flash chromatography (225 g silica; 2:1, then 1:1 hexane-ether, then 100% ether) gave the title compound (4.4 g, 79% yield) as a white solid.

Provenance & Evidence