tert-Butyl 4-oxopiperidine-1-carboxylate → HCID 69842491, compound

Participants

Reaction Steps

A solution of 2-bromoquinoline (2.0 g, 9.61 mmol) in tetrahydrofuran (10 mL) was added dropwise to a mixture of n-butyllithium in hexane (4.2 mL of a 2.5 M solution) and tetrahydrofuran (10 mL) at −65° C. under N2, and the mixture was stirred at this temperature for 1 hour. A solution of t-butyl-4-oxo-1-piperidine carboxylate (1.92 g, 9.61 mmol) in tetrahydrofuran (10 niL) was added dropwise over 3 minutes., after the addition, the reaction was slowly warmed to ambient temperature and stirred for 16 hours. The reaction was quenched with sat. ammonium chloride (15 mL); the resulting mixture was stirred at ambient temperature for 10 minutes. The organic layer was separated, washed with water (20 mL), brine (20 mL), dried over magnesium sulfate. Concentration yielded 4-hydroxy-4-quinolin-2-yl-piperidine-1-carboxylic acid tert-butyl ester (3.16 g, 98%) as a yellow oil which was used without further purification. 1H NMR CDCl3 δ 8.20 (d, J=9 Hz, 1H), 8.08 (d, J=8 Hz, 1H), 7.83 (d, J=8 Hz, 1H), 7.73 (t, J=8 Hz, 1H), 7.55 (t, J=7 Hz, 1H), 7.42 (d, J=9 Hz, 1H), 5.94 (brd s, 1H), 4.23-4.00 (m, 2H), 3.70 (t, J=6 Hz, 1H), 3.40-3.22 (m, 2H), 2.42 (t, J=6 Hz, 1H), 2.13-1.98(m, 2H), 1.49 (s, 9H).

Provenance & Evidence