Tert-butyl 4-hydroxypiperidine-1-carboxylate → HCID 49759211, compound

To a mixture of tert-butyl 4-hydroxypiperidine-1-carboxylate (1.49 g) and tetrahydrofuran (30 mL), potassium tert-butoxide (830 mg) was added under ice cooling and stirred for 30 minutes, followed by addition of a mixture of 4-fluoro-2-methoxy-1-nitrobenzene (1.00 g) and tetrahydrofuran (20 mL). After stirring at room temperature for 3 hours, the reaction mixture was extracted by addition of water and ethyl acetate, washed with saturated aqueous sodium chloride, and then dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (eluent; n-hexane:diethyl ether=4:1) to give tert-butyl 4-(3-methoxy-4-nitrophenoxy)piperidine-1-carboxylate (898 mg).