Triphenylphosphine → 4-(7-Fluoro-3-methoxycarbonylmethyl-naphthalen-1-yloxy)-piperidine-1-carboxylic acid tert-butyl ester

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Reaction Steps

To a solution of (6-fluoro-4-hydroxy-naphthalen-2-yl)-acetic acid methyl ester (500 mg, 2.1 mmol), 4-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (640 mg, 3.2 mmol) and triphenylphosphine (840 mg, 3.2 mmol) in anhydrous tetrahydrofuran (20 ml) was added diethyl azodicarboxylate (0.5 ml, 3.2 mmol) dropwise. After being stirred under an argon atmosphere at room temperature for 4 hours, the mixture was diluted with water (15 mL), and extracted with ethyl acetate (20 mL×2). The combined organic layers were washed with brine (20 mL), dried over sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by column chromatography (elution with 20% ethyl acetate in hexanes) to give 4-(7-fluoro-3-methoxycarbonylmethyl-naphthalen-1-yloxy)-piperidine-1-carboxylic acid tert-butyl ester (740 mg, 84%) as a pale yellow solid.

Provenance & Evidence