Potassium bis(trimethylsilyl)amide → 3-(9-chloro-3-methyl-4-oxo-5H-isoxazolo[4,3-c]quinolin-5-yl)-piperidine-1-carboxylic acid methyl ester

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Reaction Steps

Add potassium bis(trimethylsilyl)-amide (5.5 mL, 2.73 mmol, 0.5 M in toluene) to a solution of 3-{[3-(2-chloro-6-fluoro-phenyl)-5-methyl-isoxazole-4-carbonyl]-amino}-piperidine-1-carboxylic acid methyl ester (0.72 g, 1.82 mmol) in dimethylformamide (56 mL). After 5 minutes, quench the reaction with 1N HCl and concentrate. Partition the resulting material between 20% isopropanol/chloroform and 1N HCl. Wash the organic layer with saturated aqueous sodium bicarbonate solution and brine, dry over magnesium sulfate, and concentrate. Purify by flash chromatography on silica gel (eluting with 0–0.5% methanol/chloroform) to give 632 mg of the title compound as a white solid, 92% yield. 1H NMR: consistent with structure. MS (ion spray) 376 (M+).

Provenance & Evidence